Ebook Ballenger’s otorhinolaryngology head and neck surgery (17/E): Part 2

(BQ) Part 2 book “Ballenger’s otorhinolaryngology head and neck surgery” has contents: Anatomy and physiology of the oral cavity, deep head and neck space infections, airway management in the infant and child, congenital anomalies of the larynx,… and other contents.

The child born with a malformed ear faces a

lifelong hearing and communication impairment

along with the social stigma of a facial deformity

Associated disturbances of the vestibular system

may add the developmental hurdle of a motor

delay Frequently, there are additional anomalies,

such as mandibular hypoplasia, as well as other

facial and skeletal deformities There may be

dys-function of associated neural pathways, including

cranial nerves and intracranial structures

Addi-tionally, there are psychological factors to be

considered, including parental guilt, peer ridicule,

and the shame of “being different.” Educationally

and economically, these hearing-impaired

chil-dren face the prospect of limited opportunities

The appropriate management involves

recog-nizing the problems and limitations of therapy,

which need to be thoroughly understood by the

parents and, when appropriate, the patient

EMBRYOLOGY OF ATRESIA AND

MICROTIA

In the 3 to 4 mm embryo (3 to 4 weeks), the fi rst

indications of aural ontogenesis are the fi rst and

second branchiomeric structures and the otic

plac-ode, an ectodermal thickening on the lateral

sur-face of the head opposite the fourth ventricle The

placode invaginates to fi rst form a pit and then a

vesicle detached from its surface origin This

oto-cyst forms the inner ear membranous structures,

with the endolymphatic duct developing fi rst at

the 6 mm stage, followed by the appearance of

the semicircular ducts and the cochlear

diverticu-lum at the 15 mm stage (6 weeks) By the end of

the third month, the cochlea is fully coiled

The cranial nerves entering the otocyst exert an

inductive infl uence to produce neuroepithelium,

for which retinoic acid is a potent morphogen

Retinoic acid receptors are uniquely expressed in the developing organ of Corti; medications that affect retinoic acid metabolism, such as isotreti-noin (Accutane, Roche, Nutley, New Jersey), can lead to embryopathies, including inner ear mal-formation.1

The cochleovestibular ganglia develop from the otic placode epithelium The nerve fi bers themselves not only influence sensory cell development but are also directed to the develop-ing inner ear by the sensory cells.2

As the membranous structures of the inner ear form, they become enveloped in a cartilaginous capsule, which eventually gives rise to the petrous portion of the temporal bone Concurrently, the structures that originate from the fi rst pharyngeal pouch develop separately but adjacent to the otic capsule derivatives The pouch begins to form in the 3 to 4 mm embryo and expands into a tubotym-panic recess, which will eventually give rise to the eustachian tube, middle ear space, and mastoid air cell system The third branchial arch migrates superiorly to the level of the recess, and its artery (the internal carotid) comes to lie dorsal to the eustachian tube Variations in this relationship may result in a lateralized displacement of the internal carotid artery into the middle ear space

In adults, an ectopic carotid artery can be mistaken for a middle ear mass, such as a glomus tumor

As the pharyngeal pouches form in the 3 to

4 mm embryo, corresponding grooves develop

on the external surface of the nascent cervical region The fi rst of these branchial clefts deep-ens until it approaches the tubotympanic recess, being separated only by the thin layer of meso-derm destined to become the middle fi brous layer

of the tympanic membrane Subsequently, in the

30 mm embryo (8 weeks), the primordial external canal becomes occluded by an ectodermal plug

By the twenty-fi rst week, this begins to resorb

to form the defi nitive external auditory canal, replete with its hair and glandular appendages Aberrations in the canalization process can lead

to stenosis, canal tortuosity, or fi brous or osseous obliteration Since middle ear structures develop independently, the tympanic cavity and ossicles may be normal

Defects in the canalization process may also

be associated with faulty formation of the pinna, which arises in the 8 to 11 mm embryo from six mesodermal thickenings These hillocks sur-round the entrance of the fi rst branchial cleft The

fi rst branchial arch cartilage (Meckel cartilage) forms the tragus and superior helical crus; the remainder of the pinna derives from the second arch cartilage (Reichert cartilage), although some authorities posit a hyoid arch derivation for all but the tragus The developing auricular appendage migrates from its initial position in the lower face toward the temporal area This movement occurs along the fusion plane of the fi rst and second branchial arches The auricle is initially located anteriorly in a horizontal axis; with develop-ment of the branchial structures it migrates from its original position in the lower face laterally, and as its axis rotates, it assumes a more verti-cal angulation Branchial cleft dysmorphogenesis can impede this migration and leave the pinna in

a low, transverse orientation (Figure 1)

As the middle ear forms, the tion between the fi rst pharyngeal pouch and cleft is fi lled in by mesenchyme In the 8 mm embryo (6 weeks), part of the connective tis-sue condenses to form the malleus handle; the subsequent expansion of the tympanic cavity

separa-▼

760 PART IV / Pediatric Otorhinolaryngology

superiorly is delayed until the cartilaginous otic

capsule fully forms The expansion of the fi rst

pharyngeal pouch results in the envelopment of

the ossicles in an endodermal epithelium The

ossicles predominantly originate from

mesenchy-mal visceral bars of the fi rst and second arches

The fi rst arch forms the head of the malleus and

body of the incus, with the second arch giving

rise to the manubrium, long process of the incus,

stapes superstructure, and lateral portion of the

footplate The medial lamina of the footplate

is derived from the otic capsule The obturator

foramen of the stapes forms around the stapedial

artery, which usually remains diminutive while

the stapes enlarges If variations in vascular

development cause enlargement of the artery, a

conductive hearing loss may result from

impair-ment of stapes motion As the derivatives of the

fi rst pharyngeal pouch continue to extend into

the developing temporal bone, the antrum,

mas-toid air cells, and petrous pyramid cells begin to

form Most mastoid development is postnatal;

abnormalities that arrest middle ear formation

result in a poorly pneumatized bone

The facial nerve is intimately related to

the development of the middle and inner ear

structures outlined above The blastema of the

stapes is adjacent to the seventh nerve, which

divides the second (hyoid) visceral mesenchymal

bar into a laterohyale, stapes blastema, and

inter-hyale The interhyale forms the stapedius tendon,

whereas the laterohyale forms part of the bony

fallopian canal and pyramid Thus, the

develop-ment of the stapes is closely related to that of the

facial nerve Abnormalities in the development

of the stapes are frequently associated with facial

nerve anomalies This relationship of facial nerve

to developing middle ear structures increases the

likelihood of an anomalous course of the nerve in

the malformed middle ear.3,4 Development of the

ear is also discussed in Chapter 2, “Development

of the Ear.”

ETIOLOGY OF AURAL ATRESIA

Atresia and microtia are part of several known syndromes associated with inherited defects or acquired embryopathies owing to intrauterine infection (rubella, syphilis), ischemic injury (hemifacial microsomia), or toxin exposure (tha-lidomide, isotretinoin)

Although inner ear abnormalities, such as Usher syndrome, Waardenburg syndrome, and the neurofi bromatoses, are becoming understood

on a molecular biologic basis, the genetic basis

of external and middle ear anomalies generally remains poorly characterized.5 Aural atresia occurs

in approximately 1 in 20,000 live births Although the inner and middle ears develop separately, inner ear abnormalities coexist in 12 to 50% of cases

Atresia is bilateral in 30% of cases, occurring more commonly in males and in the right ear.6

Microtia occurs in 1 in 7,000 live births and can be associated with aural atresia Microtia represents a failure of normal development of

fi rst and second branchial arch fusion It is more common in males (two-thirds) and in the right ear (60%) Ten percent of cases are bilateral

Prenatal maternal history is not associated with the development of microtia

Children with microtia should be screened for hemifacial microsomia and other fi rst and second arch anomalies, and coordination of care with a maxillofacial surgeon beginning at an early age can be critical in optimizing facial symmetry

It is not surprising that an embryonic insult severe enough to cause aural atresia would also affect other organ systems The following organs

or systems may be anomalous in patients with atresia: neurocranium defects (Crouzon dis-ease or craniofacial dysostosis), central nervous system (mental retardation), oral cavity (fi rst and second branchial arch syndromes), the eye (Goldenhar syndrome), the neck (branchial fi s-tula), the CHARGE association (coloboma, heart defect, choanal atresia, retarded growth, geni-tourinary defects, and ear anomalies), Treacher Collins syndrome (mandibulofacial dysostosis), Duane syndrome (abducens palsy with retracted globe), VATER complex (probable disorganiza-tion of the primitive streak with impairment of early mesodermal migration causing vertebral defects, anal atresia, tracheoesophageal fi stula, renal defects, and genital anomalies), and Pierre Robin syndrome Chromosomal anomalies affect-ing the external and middle ears include Turner syndrome and trisomy 13 to 15, 18, 21, and 22 syndromes.7

Anomalies of the ear in the absence of dromes are usually not familial From the above information, it is obvious that other congenital anomalies should be assiduously sought; some, such as renal dysgenesis, may not be readily apparent A chromosomal analysis may be indi-cated As progress is made in the identifi cation of genes and their products in the recently mapped human genome, the genetic basis for many of these disorders may provide a means of treat-ment or prevention.8 The genetic and molecular

syn-Figure 1 This child’s auricle has not migrated from its

embryonic low, transverse position.

determinants of malformations of the ear are cussed in Chapter 2, “Development of the Ear.”

dis-DIAGNOSIS AND EVALUATION

In the more severe cases of microtia, the nosis is apparent on inspection of the external ear Depending on the degree of the abnormal-ity, the microtic ear may be classifi ed into three grades In grade I, the auricle is developed and, though misshapen, has a readily recognizable, characteristic anatomy (Figure 2) In grade II, the helix is rudimentary and the lobule developed (Figure 3) In grade III, an amorphous skin tag

diag-is present9 (Figure 4) Grade III microtia can be further described as conchal remnant or lobu-lar remnant Lobular remnants typically present with a vertically oriented skin covered mass of deformed cartilage superiorly, extending into a soft tissue and skin portion inferiorly Conchal remnant microtias present with all of the above, with additionally a blind pouch, which represents

a primitive conchal bowl In all stages, wide ations of morphology exist The pinna may be fully formed with a transverse and low-set orien-tation There may be accessory appendages of the pinna (pretragal tags with or without cartilage) and preauricular sinus tracts The external canal may be stenotic or atretic to varying degrees10

vari-(Figure 5) In cases of stenosis, entrapped squamous cell epithelium may lead to a retention cholesteatoma with bone destruction

Schuknecht observed that in 7 ears with genital meatal stenosis, all had cholesteatomas, whereas 3 of 11 ears with partial atresia and nar-rowed canals had cholesteatoma.11 In 50 ears with complete atresia, only 2 had cholesteatomas

con-Abnormalities of the tympanic cavity alone may occur with a normal tympanic membrane and external ear In ears with conductive hear-ing losses and normal otoscopic examinations, isolated ossicular anomalies should be suspected (Table 1) Ossicular fi xation can be produced by

a variety of abnormalities and may involve the stapes, incus, or malleus Alternatively, there may be a failure of bone development produc-ing an ossicular discontinuity, which generally involves the incus and/or stapes arch Ossicular malformations caused by abnormalities related

to fi rst or second branchial cartilaginous tives can frequently be surgically repaired (see Table 1, groups I and II) However, ossicular

deriva-fi xations owing to cochlear capsule ties, especially when associated with an aberrant facial nerve, may not be surgically correctable (see Table 1, group III) Otic capsule abnor-malities producing stapedial fi xation are fre-quently associated with abnormal communica-tion between the inner ear and the subarachnoid space In these instances, manipulation of the stapes results in a persistent gusher of cerebro-spinal fl uid Vascular malformations also occur

abnormali-in the middle ear, such as high jugular bulb, sistent stapedial artery, and anomalous course of the carotid artery.12

per-CHAPTER 62 / Microtia, Canal Atresia, and Middle Ear Anomalies 761

Further delineation of structural abnormalities requires computed tomography (CT).13 Younger children may require sedation if they are unable to cooperate The images are processed with a bone algorithm image enhancement using 1.5 mm slices

at either 1.5 or 1 mm intervals Optimally, both axial and coronal scans are obtained, although reformatted coronal or sagittal images may be adequate Three-dimensional reconstruction may

be useful in visualizing the temporal bone raphy.13,14 Auditory brainstem responses (ABRs) should be performed in all children born with either microtia or atresia as neonates In cases of microtia with fairly normal canals, an ossicular malformation producing a conductive hearing loss may be present In patients with unilateral atresia, it is not unusual for the seemingly normal contralateral ear to have a hearing loss Bilateral involvement may cause masking dilemmas; such

topog-is the case when one ear has a conductive loss and the other a sensorineural loss These dilemmas may be minimized by using multichannel analy-sis of ipsilateral versus contralateral responses to determine the laterality of wave I.15 As the infant matures, behavioral audiometric evaluations must

be obtained to confi rm the neurophysiologic tests

of hearing In children older than 1 year, ditioned free fi eld play audiometry should help

con-to quantify the overall hearing levels ally, pure-tone and speech testing with masking should be obtained in children with fairly normal canals Impedance and stapedial refl ex measures

Eventu-in a seemEventu-ingly normal ear can provide valuable information as well as more extensive malforma-tions occurring in Treacher Collins syndrome and hemifacial microsomia CT studies allow deter-mination of the degree of the canal atresia, the thickness of the atresia plate (Figure 6A), the extent of pneumatization of the middle ear and mastoid, the distance between the glenoid fossa and mastoid, the intratemporal course of the facial nerve, the status of the malleus and incus, and, in some instances, the presence or absence of the stapes and oval window (Figure 6B) However, subtleties of oval and round window anatomy are often not revealed An unsuspected cholesteatoma may also be apparent The normalcy of the osse-ous inner ear structures is also revealed by CT

Figure 3 An example of a grade II microtia The auricle

is reduced in size and has a characteristic recognizable

shape The inferior and superior crura have not developed,

although the helix is well preserved.

Figure 4 Auricle showing a grade III microtia An

amor-phous ridge of skin and nubbins of cartilage are present in place of a recognizable, well-developed auricle.

Figure 2 This pinna exhibits a grade I microtia with canal

atresia The size of the auricle and the characteristic

ana-tomic landmarks are fairly normal A pretragal skin tag is

present.

Table 1 Congenital Middle Ear Abnormalities with Patent Ear Canal, Mobile Tympanic Membrane, and Conductive Loss

I Ossicular fi xation

a Stapes fi xation

1 Defi cient annular ligament

2 Elongated pyramidal process, ossifi ed stapedial tendon

b Malleolar-incudal fi xation

1 Lateral epitympanic ankylosis

2 Medial epitympanic ankylosis of body of incus, head of malleus

3 Ossifi ed anterior malleolar ligament

II Ossicular discontinuity

a Absent stapes arch

b Defi cient lenticular process of incus

c Defi cient long process of incus III Cochlear capsule and facial nerve anomalies

a Aplasia of oval or round window

b Facial nerve anomaly occluding oval window

c High jugular bulb occluding the round window niche

Figure 5 A grade II to III microtia with poor formation of

the superior third of the auricle and a preauricular pit, sibly because of a fi rst branchial arch dysmorphism The lower portion of the ear, which is derived from the second branchial arch, has a relatively normal appearance The canal is stenotic, leading to the subsequent development

pos-of a retention cholesteatoma.

762 PART IV / Pediatric Otorhinolaryngology

Evaluation of the function of other organ

sys-tems should be considered by the otologist For

example, some of the syndromal associations of

atresia involve mandibular and laryngeal

anoma-lies that can lead to airway obstruction; cardiac,

renal, endocrine, and immune function should be

ascertained in selected instances

MANAGEMENT OF AURAL ATRESIA

AND MICROTIA

Nonsurgical

The prime concern in the young child is the

assessment and improvement of hearing When

ear deformities are present, the ABR techniques

outlined above are helpful in determining the type

and severity of hearing loss and should be

performed as early in life as possible Early amplifi

-cation, auditory training, and speech therapy can

improve speech and language skills In children

with bilateral atresia, amplifi cation with

bone-conduction aids should be provided as soon as

possible, preferably within the fi rst few months

of life.16–18 In infants with a unilateral atresia and

conductive hearing loss in the seemingly normal

ear, an air-conduction aid should be fi tted to the

ear with a canal

Surgical

In the unilateral case with normal contralateral

hearing, repair of either the microtia or the atresia

is considered elective, and there is less urgency

to intervene during childhood When the atresia

is bilateral with acceptable-appearing auricles,

reconstructive surgery can be performed at a

fairly young age However, in cases of microtia

that require reconstruction, atresia repair should

be deferred until the initial stages of the auricular

repair are completed Generally, microtia surgery

requires a cartilage graft that is obtained from

the lower costochondral region An adequate

graft requires suffi cient growth and fusion at the

donor site, which has usually occurred by 5 to

6 years of age Additionally, in bilateral cases, many authorities recommend postponing surgery for the restoration of hearing until at least age fi ve

so that pneumatization can develop.11 In children with frequent upper respiratory infections and suspected eustachian tube dysfunction, it may also be necessary to delay hearing reconstructive surgery

Surgical Treatment of Congenital Conductive Hearing Loss The success of the surgical cor-

rection of congenital conductive hearing losses

is related to the abnormality since a wide range

of malformations is possible.10 Surgery in an ear that has an isolated ossicular malformation with an otherwise patent canal, intact tympanic membrane, aerated middle ear cleft, normal facial nerve, and mobile stapes has the potential for excellent hearing (Table 2, class I) Conversely,

an ear with canal atresia, a narrowed and poorly aerated middle ear space, and an anomalously positioned facial nerve occluding the oval win-dow is destined to have poor postoperative hear-ing (see Table 2, class III) Between these two extremes is an array of anomalies with variable surgical outcomes Even with sophisticated

imaging techniques, the preoperative prediction

of what awaits the otologist is not always rate.19

accu-Surgeons wishing to correct congenital ductive hearing losses are embarking on a pro-cedure with signifi cant potential complications

con-Generally, the initial attempt is the procedure most likely to improve the hearing Unplanned revisions are often more complex and less suc-cessful Additionally, if a signifi cant sensorineu-ral hearing loss occurs after surgery in a patient with bilateral malformations, the opposite ear

is effectively excluded from surgical correction since it becomes the better hearing ear Before assuming this responsibility, especially in chil-dren, the otologic surgeon must have suffi cient experience to maximize the likelihood of a suc-cessful outcome

The presence of a conductive hearing loss in

an ear with a normal canal and mobile drumhead generally indicates that the ossicular chain is not transmitting sound energy to the cochlea Isolated ossicular malformations involving the stapes arch and long process of the incus may not be appreci-ated on CT studies In these cases, the middle ear can be explored by elevating a tympanomeatal

fl ap and assessing the normalcy of the ossicular transduction mechanism If the canal is small, a postauricular approach will improve operative exposure Frequently, even the young child’s ear canal has a suffi cient diameter to admit an adequately sized ear speculum, even though the length of the canal is shorter

Once the middle ear is entered, the surgeon needs to decide if the chain is fi xed If so, what is the cause of the fi xation (see Table 1) First, the motility of the incus and malleus is ascertained

Is the fi xation in the epitympanum and, if not, where (Figure 7)? Drilling away the bone over the malleus head and body of the incus provides the required exposure to explore this area Is the sta-pedial tendon ossifi ed? If the stapes is fi xed, mobi-lization may produce a sustained improvement

Alternatively, a stapedectomy using a replacement prosthesis with an oval window tissue graft to

(B)

(A)

Figure 6 (A) A coronal computed tomographic (CT) scan showing a bony atresia plate (arrow) The middle ear space

is normally pneumatized (B) Coronal CT scan showing a low-lying tegmen (T), which precludes construction of an

external canal The middle ear cleft has not developed A rudimentary antrum is unaerated (A) Atresia surgery is

con-traindicated in this case.

Figure 7 A coronal computed tomographic scan in a

patient with a congenital conductive hearing loss caused

by osseous fi xation of the malleus head to the lateral

epi-tympanic wall (arrow).

Table 2 Congenital Atresia Classifi cation

Class I

a Aerated normal middle ear space

b Developed oval window with mobile stapes

c Oval window not obstructed by facial nerve Class II

a Narrowed, but aerated, middle ear space

b Fixed stapes, oval window aplasia

c Oval window not obstructed by facial nerve Class III

a Nonaerated, hypoplastic middle ear space

b Oval window obstructed by facial nerve

c Tegmen low hanging, obstructs access to middle ear space

CHAPTER 62 / Microtia, Canal Atresia, and Middle Ear Anomalies 763

prevent a perilymphatic leak may be performed

In some cases, the surgeon may elect to defer

stapes surgery until the child is grown

A gap interrupting the ossicular chain’s

conti-nuity occurs most commonly at the

incudostape-dial joint, either owing to absence of the lenticular

process or long process of the incus or the stapes

arch The presence of a mobile stapes facilitates

the surgery and greatly improves the operative

result A variety of techniques have proven useful

in the restoration of ossicular chain continuity by

means of bridging an existing gap If there is a

small distance between the stapes capitulum and

the long process of the incus, a tragal cartilage

graft can successfully negotiate the gap Defi

-ciencies of the long process of the incus can be

corrected by either interposing the reshaped incus

between the mobile stapes and the malleus

han-dle or using an alloplastic prosthesis designed for

this purpose (type III tympanoplasty) When the

stapes arch is absent, similar procedures can be

performed to bridge the gap from either the

mal-leus handle or the undersurface of the drumhead

to the mobile footplate (type IV tympanoplasty)

A coexisting fi xation of the stapes or obstruction

of the oval window by the facial nerve increases

the technical diffi culty, yields poorer hearing

results, and increases the chance of

complica-tions, such as sensorineural hearing loss or facial

nerve injury.20

Surgery for Microtia and Canal Stenosis or

Atresia Congenital malformations of the

auri-cle, external canal, and middle ear may occur as

isolated abnormalities or in various

combina-tions Reconstruction of the external ear is

usu-ally performed by a plastic surgeon, whereas

external auditory canal and middle ear defects are

corrected by the otologist; both work as a team to achieve the optimal result

Microtia surgery is technically diffi cult, and not infrequently, the results are somewhat dis-appointing The surgery should be performed

by individuals with special expertise.21 lar reconstruction is an elective procedure The deformity can usually be masked by a longer hair style Generally, the slight deformity of a grade I microtia may be cosmetically acceptable

Auricu-Reconstruction of a moderately deformed grade

II microtia must be individualized Correction of

a severe grade III microtia requires several staged procedures

Treatment of microtia must begin with a frank discussion of the surgical and nonsurgical options with the patient’s parents, as well as surgical tim-ing considerations Generally, surgery is deferred until the child reaches 5 to 6 years of age Prior to this, the contralateral ear is undersized and under-developed and available costal cartilage is lim-ited; moreover, the child is not suffi ciently mature

to comply and assist with postoperative care nifi cantly, children younger than 5 years of age generally have not been stigmatized because of their deformity by their peers

Sig-The standard surgical technique for microtia reconstruction has been well-described by Tan-zer22 and subsequently refi ned by Brent.23 Dur-ing the fi rst stage, costal cartilage is harvested from the contralateral sixth to eighth ribs using a curvilinear incision near the medial aspect of the costal margin A template based on the contralat-eral ear is made from sterilized, exposed radio-graphic fi lm and accurately copies the contour

Figure 8 Costal cartilage framework for repair of right

microtia Sixth and seventh rib cartilage is used to

recre-ate the antihelix and conchal bowl; eighth rib cartilage is

thinned and sutured to sixth and seventh rib cartilage to

serve as the helical rim.

Figure 9 At the conclusion of the fi rst stage, the

frame-work has been placed and suction drains coapt skin to the framework.

Figure 10 Prior to the second-stage procedure, the

lobu-lar remnant is displaced anteriorly and is separate from the tail of the neohelix.

and size of the pertinent structures of the mal auricle (Figure 8) Using the template as a guide, the appropriate sections of costal cartilage are harvested The medial portion of the seventh rib will serve as the posterior rim of the conchal bowl and superior crus, and the synchondrosis between the sixth and seventh ribs is harvested

nor-en bloc with the sevnor-enth rib and is later sculpted

to serve as the inferior crus A segment of the eighth rib is harvested separately and is used to

Figure 11 At the conclusion of the second stage, the

lob-ule has been transposed using a Z-plasty technique.

764 PART IV / Pediatric Otorhinolaryngology

construct the helical rim which generally requires

at least an 8 cm long segment Great care is taken

to dissect in a subperichondrial plane on the deep

side to avoid puncture of the parietal pleura and

a pneumothorax Once all cartilage is harvested,

meticulous hemostasis is ensured The wound is

then fi lled with warm, sterile saline, and

posi-tive pressure ventilation manually applied and

held by the anesthesiologist for 10 seconds If

no bubbles indicative of an air leak are observed,

the wound is drained and closed in layers;

how-ever, if an air leak is identifi ed, the site of pleural

injury is identifi ed If small, a red rubber catheter

is placed through the pleural tear, and a purse string suture is placed around the periphery of the tear The suture is then tied as suction is applied through the catheter as it is withdrawn Patients are followed by serial chest X-rays to ensure that

a pneumothorax does not develop Larger pleural injuries may require chest tube placement

The individual pieces of cartilage are then carved using the template as a guide Finally, the eighth rib is thinned to allow it to be curled around the conchal and antihelical framework, and the two pieces are sutured to each other with clear nylon sutures It is important when constructing the framework to exaggerate features, as these will be blunted by the thicker temporal skin

Next, the unusable portion of microtic appendage is removed, generally consisting of the

superior “knot” of deformed cartilage; the rior portion is retained for later reconstruction of the lobule Using the contralateral ear as a guide, the ideal position of the reconstructed auricle is determined and marked A 2 cm curvilinear inci-sion is then made approximately 2 cm above the location of the superior part of the helix, and

infe-a subcutinfe-aneous dissection is performed under the markings for the auricle location and car-ried approximately 1 cm beyond these mark-ings to allow for appropriate skin draping The framework is then carefully positioned in the skin pocket, with care taken to ensure proper positioning and orientation Residual cartilage is banked subcutaneously under hair bearing tem-poral skin Two 4 mm drains are then positioned

to coapt the skin to the framework and to ate any blood or serum and are left on gentle

evacu-Figure 12 During the third stage of microtia repair, the

framework is elevated from the temple, the posterior scalp

is advanced into the postauricular sulcus and the bare areas

of the auricle and sulcus covered with a skin graft.

Figure 13 Healed auricle after three stages of repair,

prior to atresia repair Blue dotted line indicates incision

that will be made for the atresia repair.

(B) (A)

Figure 14 Placement of osseointegrated implants for attachment of a prosthetic pinna (A) The percutaneous abutments

and associated wire framework used to attach the right prosthetic pinna via clips (B) The normal left pinna can be seen

(C) The right prosthetic pinna in place It should be noted how similar the prosthesis appears compared to the normal pinna seen in B (D) Oblique view of the prosthetic pinna (Published with permission, copyright © 2007 P A Wackym, MD.)

CHAPTER 62 / Microtia, Canal Atresia, and Middle Ear Anomalies 765

The timing of the microtia and atresia repairs requires close communication between the sur-geons Because scarring interferes with the auricular repair, reconstruction of the atresia is deferred until the auricular cartilaginous scaffold-ing is completed However, it is important to posi-tion the reconstructed auricle correctly so that it aligns with the meatal opening and the middle ear

The meatal, canal, and middle ear reconstruction

is frequently performed as part of the second or third stage of the auricular reconstruction.13,26

A postauricular approach is used, with great care being taken to avoid exposing the scaffold (Figure 15) Temporalis fascia is harvested for reconstruction of the tympanic membrane The periosteum of the lateral surface of the temporal bone is elevated A bony circular canal is cre-ated by drilling between the glenoid fossa ante-riorly and the tegmen plate superiorly while trying to avoid entering mastoid air cells poste-riorly (Figure 16) Continuous suction irrigation cools the bone and clears away blood and bone dust while the water enhances the translucency of the wet bone This permits visualization of struc-tures such as dura, facial nerve, and glenoid fossa through the intact thinned bone The surgeon should anticipate that the facial nerve will be located more anteriorly and more laterally than in the normal temporal bone The nerve frequently follows a C-shaped path in its course between the geniculate ganglion and its point of emergence from the temporal bone The purposeful identifi -cation of the facial nerve will prevent inadvertent injury A facial nerve monitor may facilitate iden-tifi cation of the nerve in atretic ears

Visualization of the facial nerve as a landmark permits the opening of the atresia plate to approx-imate the size of a normal middle ear opening

While drilling on this plate, it must be bered that the malleus handle may be fused to it

remem-Precautions must be taken to avoid drilling on the mobilized atresia remnant since this may transmit traumatic vibratory energy through the ossicular chain to the inner ear and result in a permanent sensorineural hearing loss (Figure 17)

The status of the ossicular chain is assessed

If the stapes is mobile, an appropriate ossicular reconstruction is performed (Figure 18) If it is

fi xed or the oval window is obscured by the facial nerve, the ossicular reconstruction should be deferred Temporalis fascia is used to fabricate a

Figure 15 Surgery for canal atresia A postauricular

incision is made While exposing the mastoid cortex and

dysmorphic tympanic bone, the previously implanted

car-tilaginous auricular scaffold should be protected during

retraction.

Figure 16 Construction of a canal is begun by drilling

between the glenoid fossa anteriorly and the superior

tem-poral line The latter roughly corresponds to the tegmen

(fl oor of the middle cranial fossa) When possible, entry

into the mastoid air cells is avoided TMJ =

temporoman-dibular joint.

Figure 17 Drilling is continued until a normal-sized

mid-dle ear opening has been created Great care is taken not to drill on a mobile, deformed, but intact ossicular chain The anteriorly coursing facial nerve is identifi ed.

Figure 18 The ossicular chain is reconstructed by

inter-posing the malformed, sculpted ossicle onto the stapes

Silastic sheeting, 0.005 in thick, is positioned to prevent bony ankylosis.

suction for 3 to 4 days (Figure 9) The incision is

closed with nylon suture

Two to three months after the fi rst stage,

lobule creation can be performed Essentially,

Z-plasty double transposition fl aps reorient the

vertically positioned skin tag to align with the

inferior part of the helical tail while the skin from

this area is transposed anteriorly to close the

donor site (Figures 10 and 11) In conchal

rem-nant microtias, transposition of the remrem-nant can

construct an inferior conchal bowl, lobule and,

occasionally, an antitragus

Two to three months later, the third stage of

reconstruction is performed A split thickness skin

graft (0.015 to 0.020 in thick) is harvested from

the posterior aspect of the thigh An incision is

then made approximately 8 to 10 mm peripheral to

the buried framework, from the anterior part of the

helix down to the repositioned lobule The

frame-work is then elevated, leaving a generous amount

of scar and subcutaneous tissue on the medial

aspect of the framework The banked costal

car-tilage is retrieved and sutured to the anteromedial

aspects of the framework to maintain

lateraliza-tion Posteriorly the scalp is undermined widely

and advanced into the postauricular sulcus, and

the portions of the sulcus and auricle still bare are

covered with the skin graft A bolster dressing is

placed into the postauricular sulcus and left for 1

week (Figure 12) Atresia repair can be performed

3 to 4 months later (Figure 13) An additional

stage can reconstruct the tragus using a portion

of the contralateral conchal bowl as a composite graft several months after atresia repair

Alternatives to this standard approach for reconstruction exist An externally mounted pros-thesis can be modeled on the normal ear and can appear quite realistic However, the prosthesis needs to be mounted onto the temporal skin with adhesives on a daily basis Percutaneous osseointegrated implants can be placed into the temporal bone and used to anchor the prosthesis more securely These prostheses need lifetime care They may become dislodged at socially inconvenient times Pediatric patients may fi nd compliance diffi cult and socially unacceptable;

however, the cosmetic result can be vastly rior compared to the multistage reconstruction approach (Figure 14) Nagata has described a two-stage procedure using autologous rib carti-lage.24 This is a technically challenging proce-dure, and results may not be as predictable as the Tanzer/Brent method Finally, a single stage procedure has been described using a porous high density polyethylene custom implant covered by

supe-a temporopsupe-arietsupe-al fsupe-ascisupe-a fl supe-ap supe-and split thickness skin graft.25 While results can be good, if fl ap failure occurs early, salvage may be diffi cult

Additionally, trauma to the implant can lead to framework cracking, and even minor injuries can lead to skin loss, implant exposure, and chronic infection Exposure of the synthetic framework

to the mastoid cavity can lead to chronic implant infection and recurrent drainage, and the prior use of a temporoparietal fascia fl ap limits the tis-sue available for salvage

Figure 19 Temporalis fascia is used to construct a

tym-panic membrane.

766 PART IV / Pediatric Otorhinolaryngology

new tympanic membrane (Figure 19) A meatal

opening is made in the area of the imperforate

concha, incising the skin to create a rectangularly

shaped, anteriorly based conchal skin fl ap The

underlying cartilage and soft tissue are removed

to debulk the fl ap and create an opening that

communicates with the drilled out external canal

(Figure 20) The conchal fl ap is rotated to

resur-face the anterior third of the external canal and is

stabilized by suturing it to the adjacent soft tissues

(Figure 21) A thin split-thickness skin graft is

harvested from the lower part of the abdomen and

is used to resurface the remaining ear canal The

canal is packed snugly with Gelfoam (Upjohn,

Kalamazoo, Michigan) to compress the skin graft

against the underlying bone and soft tissue The

postauricular incision is reapproximated using

absorbable sutures

Risks and Benefi ts of Atresia Surgery Atresia

surgery is technically demanding The results

achieved are directly related to the experience

and skill of the operating surgeon Generally,

hearing improvement to a serviceable level can

be achieved in approximately 65 to 75% of

selected patients.27,28 Complications of surgery

include the small risk of facial paralysis, a severe

to profound sensorineural hearing loss,

steno-sis requiring additional surgery, persteno-sistent

otor-rhea, and tympanic membrane graft failure with perforation

In children with a unilateral atresia and a normal contralateral ear, surgery may not be routinely indicated.19 The potential benefi t of this sophisticated surgery, that is, achieving binaural hearing, may not justify the risk of complica-tions In binaural cases, the successful creation of

an external canal, even when hearing cannot be improved, will allow the use of an ear-level air-conduction hearing aid to restore hearing with-out using a cumbersome bone-conduction aid

Thus, in bilateral cases in which the facial nerve obstructs the oval window or when a hearing improvement cannot be achieved, providing the patient with a stable, skin-lined canal is a worthy goal in and of itself

Another hearing restorative technique for external auditory canal atresia is the placement

of a bone anchored hearing aid (BAHA).29 This procedure involves implanting a titanium post which becomes osseointegrated into the cal-varia A special hearing aid is attached to this post via a percutaneous abutment and uses bone conduction to stimulate the cochlea The titanium post requires a 3-month period for osseointegra-tion in an adult and a 4- to 6-month period for children, before the external appliance can be attached to the abutment The use of the BAHA

requires at least a bone conduction threshold in one ear to be at a minimum of 40 to 45 dB to be effective

In adults, placement of the BAHA is usually performed in a one-stage procedure to implant the titanium post and abutment In children, the two-stage procedure can be employed which involves the placement of the post only and allowing it to osseointegrate for 3 to 6 months A second stage is then carried out which includes the thinning of the skin fl ap for effi cient trans-duction as well as placement of the percutane-ous abutment The external processor is fi tted 3

to 4 weeks after the skin fl ap heals Frequently,

a second “sleeper” fi xture is placed at the same time, which allows its immediate use in the future should the fi rst fi xture ever extrude or fail

to osseointegrate

The BAHA system has some distinct tages which make this procedure a viable option for atresia patients The hearing result with the BAHA is superior to an atresia repair which usually results in a mild conductive hearing loss

advan-in the best circumstances Furthermore, this cedure poses no risk to the facial nerve and is not dependent on a patent external auditory canal

pro-Succcesful atresia surgery involves a ness skin graft to resurface the bony canal This may require that the child take water precautions

split-thick-to keep the ear dry This is not a problem with the BAHA Drawbacks include failure to osseo-integrate, loss of post fi xation over time, and periodic infections around the abutment if daily cleaning is not performed In addition, there are the cosmetic issues of a permanent percutane-ous abutment and the depilated skin around the

fi xture The cosmetic issue is usually more of a concern for boys or for girls with short hair as the abutment is more apparent in these situations

REFERENCES

1 Lefebvre PP, Malgrange B, Staecker H, et al Retinoic acid stimulates regeneration of mammalian auditory hair cells

Science 1993;260:692–5.

2 Anson BJ, Davies J, Duckert LG Embryology of the ear In:

Paparella MM, Shumrick DA, Gluckman JL, et al, editors

Otolaryngology, 4th edition Philadelphia: JB Lippincott;

1991 p 3–21.

3 Williams GH Developmental anatomy of the ear In: English

GM, editor Otolaryngology Philadelphia: JB Lippincott;

1990.

4 Nager GT, Proctor B Anatomic variations and anomalies involving the facial canal Otolaryngol Clin North Am 1991;24:531–53.

5 Snow JB Preface Otolaryngol Clin North Am 1992;25:

xv–i.

6 Jafek BW, Nager GT, Strife J Congenital aural atresia: ysis of 311 cases Trans Am Acad Ophthalmol Otolaryngol 1975;80:580–95.

7 Sando IS, Shibahara Y, Wood RP Congenital anomalies of the external and middle ear In: Bluestone CD, Stool SE, edi- tors Pediatric Otolaryngology Philadelphia: WB Saunders;

1990 p 271–302.

8 Bergstrom LB Anomalies of the ear In: English GM, editor

Otolaryngology Philadelphia: JB Lippincott; 1990.

9 Teunissen EB, Cremers CWRJ Classifi cation of congenital middle ear anomalies Report on 144 ears Ann Otol Rhinol Laryngol 1993;102:606–12.

10 Jahrsdoerfer RA, Yeakley JW, Aguilar EA, et al Grading system for the selection of patients with congenital aural atresia Am J Otol 1992;13:6–12.

11 Schuknecht HF Congenital aural atresia Laryngoscope 1989;99:908–17.

Figure 20 A meatal opening is made

through the imperforate conchal skin A rectangular, anteriorly based skin fl ap is debulked and rotated to line the anterior lateral third of the new canal.

Figure 21 A thin,

split-thick-ness skin graft harvested from the lower part of the abdomen is used

to resurface the remainder of the canal Handling and placement of the graft are facilitated by gluing the epidermal surface to thin (0.005 in.) Silastic sheeting The raw surface of the graft is compressed against the bone by fi ling the canal lumen with Gelfoam.

CHAPTER 62 / Microtia, Canal Atresia, and Middle Ear Anomalies 767

12 Curtin HD Congential malformations of the ear Otolaryngol

Clin North Am 1988;21:317–36.

13 Jahrsdoerfer RA, Garcia ET, Yeakley JW, et al Surface

con-tour three-dimensional imaging in congenital aural atresia

Arch Otolaryngol Head Neck Surg 1993;119:95–9.

14 Andrews JC, Anzai Y, Mankovich NJ, et al

Three-dimensional CT scan reconstruction for the assessment of

congenital aural atresia Am J Otol 1992;13:236–40.

15 Jahrsdoerfer RA, Yeakley JW, Hall JW, et al High-resolution

CT scanning and auditory brain stem response in congenital

aural atresia: Patient selection and surgical correlation

Oto-laryngol Head Neck Surg 1985;93:292–8.

16 Granstrom G, Bergstrom K, Tjellstrom A The

bone-anchored hearing aid and bone-bone-anchored epithesis for

con-genital ear malformations Otolaryngol Head Neck Surg

1993;109:46–53.

17 van der Pouw KT, Snik AF, Cremers CW Audiometric

results of bilateral bone-anchored hearing aid application in

patients with bilateral congenital aural atresia Laryngoscope 1998;108:548–53.

18 Tjellstrom A, Hakansson B The bone anchored ing aid (BAHA) design principles, indications and long- term clinical results Otolaryngol Clin North Am 1995;

hear-115:1–20.

19 Trigg DJ, Applebaum EL Indications for the surgical repair of unilateral aural atresia in children Am J Otol 1998;19:679–84.

20 Jahrsdoerfer RA, Lambert PR Facial nerve injury in genital aural atresia surgery Am J Otol 1998;19:283–7.

21 Chandrasekhar SS, De la Cruz A, Garrido E Surgery of genital aural atresia Am J Otol 1995;16:713–7.

22 Tanzer RC Microtia: A long-term follow-up of 44 structed auricles Plast Reconstr Surg 1978;61:161–4.

23 Brent B Technical advances in ear reconstruction with ogous rib cartilage grafts: Personal experience with 1200 cases Plast Reconstr Surg 1999;104:319–24.

24 Nagata S A new method of total reconstruction of the auricle for microtia Plast Reconstr Surg 1993;92:187–93.

25 Romo T, Fozo M, Sclafani AP Microtia reconstruction using a porous polyethylene framework Facial Plast Surg 2000;16:15–22.

26 Bellucci RJ Congenital aural malformations: sis and treatment Otolaryngol Clin North Am 1981;14:

Anatomy and Physiology of the Oral Cavity

Margaret A Kenna, MD, MPH

Manali Amin, MD

63

The oral cavity is important for many vital

bodily functions including speech and

swallow-ing It is a complex space, bounded anteriorly

by the lips and posteriorly by the oropharynx

Its two compartments are the vestibule, or

exter-nal compartment, and the interexter-nal compartment

The vestibule is the space lateral to the alveolar

ridges and medial to the lips and buccal mucosa

The oral cavity proper is bounded by the alveolar

ridges laterally, the hard and soft palates

supe-riorly and postesupe-riorly and the fl oor of mouth

caudally Its primary contents are the teeth, the

anterior two-thirds of the tongue, minor salivary

glands, and the parotid and submandibular

sali-vary ducts The palatoglossus muscles form the

anterior tonsillar pillars All structures anterior to

the anterior tonsillar pillars are contained within

the oral cavity All structures posterior to the

pil-lars are part of the oropharynx The oropharynx

contains the posterior one-third of the tongue, the

lingual and palatine tonsils, and the paired

tonsil-lar piltonsil-lars formed by the palatoglossus and

pala-topharyngeus muscles It extends from the soft

palate superiorly to the base of tongue inferiorly

TONGUE

The tongue is a large muscular organ in the oral

cavity The anterior two-thirds of the tongue is

mobile and has four surfaces: the dorsum, the

ventral surface, and the lateral borders The

dor-sal surface opposes the hard palate and has an

irregular mucosal surface covered with multiple

epithelial appendages known as papillae The

ventral surface faces the fl oor of mouth and is

covered by a thin mucosal layer that meets in

the midline to form a band of tissue known as

the frenulum The mucosa is continuous with the

mucosa of the fl oor of mouth

All tongue movements are accomplished by

the anterior two-thirds of the tongue, also known

as the mobile tongue Tongue movement is

accomplished through use of both intrinsic and

extrinsic muscles The tongue is divided into

two halves by a median fi brous septum that is

fi xed to the body of the hyoid bone Each half of

the tongue contains two sets of muscles,

extrin-sic and intrinextrin-sic The extrinextrin-sic muscles are the

genioglossus, hyoglossus, and stylopharyngeus

The palatoglossus is sometimes considered an

extrinsic muscle of the tongue and sometimes a

muscle of the soft palate The extrinsic muscles

allow for tongue movement anteriorly, backward, upward, and downward The genioglossus func-tions to protrude and retract the tongue as well

as depress its tip The styloglossus and sus aid in retracting the tongue and in raising and depressing its margins respectively The intrinsic muscles are the superior and inferior longitudi-nal, transverse, and vertical The intrinsic muscles function to change the shape of the tongue during speech and swallowing The palatoglossus muscle within the anterior tonsillar pillar also elevates the tongue Although it helps with tongue movement, the primary function is in the downward move-ment of the soft palate, and it may be an important regulator in the transition from the oral phase to the pharyngeal phase of swallowing.1

hyoglos-The posterior one-third of the tongue is divided from the anterior two-thirds by an inverted V-shaped groove known as the sulcus terminalis (Figure 1) The foramen cecum, the origin of the thyroglossal duct, is at the apex of the sulcus The posterior one-third of the tongue

is composed primarily of the lingual tonsil

Motor innervation of the tongue is almost exclusively through the hypoglossal nerve, that

is, CN XII It innervates all of the extrinsic and intrinsic muscles except for the palatoglossus

The hypoglossal nerve enters the tongue on the lateral surface of the genioglossus muscle, anas-tomosing with fi bers from the lingual nerve The paired motion of the genioglossus allows for straight protrusion of the tongue When one of

the hypoglossal nerves is paralyzed, the tongue will deviate to the side of the paralysis upon protrusion The palatoglossus is innervated by branches from the pharyngeal plexus which is derived from the vagus nerve, that is, CN X

Sensory innervation of the tongue is what more complex (Table 1) (Figure 2) Gen-eral sensation (touch, pain, and temperature) of the anterior two-thirds of the tongue is carried by afferent fi bers from the third or mandibular divi-sion of the trigeminal nerve (CN V3) in the form

some-of the lingual nerve Taste in the anterior thirds of the tongue is carried by afferent fi bers

two-of the seventh cranial nerve in the form two-of the chorda tympani nerve By contrast, both general sensation and taste to the posterior one-third of the tongue are carried by afferent fi bers of the glossopharyngeal nerve

Taste Receptors

Taste is mediated through specialized tors known as taste buds Taste buds are located within epithelial appendages on the dorsal sur-face of the tongue known as papillae (Figure 3)

recep-In addition, taste buds are found in the lium of the soft palate, pharynx, larynx, epi-glottis, and esophagus Their distribution varies widely both within an individual and among individuals In general, newborns and children have a higher number of extralingual taste buds than adults.2

epithe-Taste buds are oval sensory end organs composed of 50 to 150 spindle-shaped, epithe-lial cells with receptor properties.2,3 They are involved in the perception of chemical stimuli and in taste transduction A single taste bud is

an almost ovoid structure, 70 µm in height with

a diameter of approximately 40 µm and a tral opening on its epithelial surface, known as the taste pore The taste pore, approximately 2

cen-to 10 µm in size, exposes the apical surface of receptor cells to molecular food particles dis-solved in saliva

Ultrastructurally, the taste bud is composed

of three types of cells: basal cells, edge cells, and taste receptor cells Basal cells are undif-ferentiated cells from which the other taste receptor cells are derived Edge cells, as their name suggests, defi ne the lateral aspect of the taste bud Three different types of taste recep-tor cells have been identifi ed: dark cells (type I cells), light cells (type II cells), and intermediate

Figure 1 The dorsal surface of the tongue Filiform

papil-lae cover the dorsum The lingual tonsil and palatine sils are part of Waldeyer ring.

ton-770 PART IV / Pediatric Otorhinolaryngology

cells (type III cells) Type I cells are known as

dark cells because they contain dense granules

near their apex Type II cells are known as light

cells because they lack these dense granules

Intermediate cells are felt to be intermediate

between the other two types of cells The

func-tion of these cells and how they differ from one

another or whether they represent a progression,

is not well understood.2 All three of the receptor

cell types contain microvilli at their apical end

and synapse with afferent nerve endings at their

basal end The microvilli project into the taste

pore and expose the taste receptors to gustatory

stimuli.2 The two primary classes of receptors

are the seven-transmembrane G-protein

cou-pled receptors (GPCRs) and ion channels.4 The

GPCR proteins consist of a second messenger

cascade which is activated upon binding of the

receptor The ion channels allow passage of

dif-ferent cations or protons and modulate the

mem-brane permeability The fi nal mechanism of taste

transduction, irrespective of the receptor type

stimulated, is an increase in intracellular Ca2+

and subsequent neurotransmitter release

Gustatory Papillae Taste buds are found in

both extralingual sites as well as in lingual

papil-lae The dorsal surface of the tongue has four

types of papillae: fungiform, circumvallate,

foli-ate, and fi liform The papillae have a core of

connective tissue covered with epithelium that

expresses hair-like keratins Filiform papillae

are distributed throughout the dorsal surface of

the anterior part of the tongue They are the only

form of papillae that do not contain taste buds

Their primary function is to assist with tactile aspects of feeding

The fungiform, circumvallate, and foliate papillae, collectively referred to as the gustatory papillae, differ from fi liform papillae in that their epithelial covering contain sense organs capable

of perceiving taste The fungiform papillae, as their name suggests, are mushroom-shaped, raised structures found on the anterior two-thirds of the tongue surface There are 200 to 300 fungiform papillae containing a total of nearly 1,600 taste buds on the human tongue.3 The foliate papil-lae are found on the posterolateral surface of the tongue and contain approximately 1,000 taste buds.3 Finally, the circumvallate papillae are found in an inverted V-shape along the anterior margin of the sulcus terminalis Similar to the sulcus, it marks the division between anterior and posterior parts of the tongue There are a total

of 8 to 12 circumvallate papillae, containing approximately 250 taste buds each.3 The circum-vallate papillae are associated with deep lingual salivary glands also known as von Ebner glands

Von Ebner glands secrete serous saliva and open into the trenches around the circumvallate papil-lae and into mucous glands found in the poste-rior part of the tongue Mucous glands are found within the crypts of the lingual tonsil.5,6

The exact function of the von Ebner glands remains debatable One study has shown that they may have three possible functions.5 First, they produce a digestive enzyme, lingual lipase, which may be important in the neonatal period when pancreatic function is limited and pancreatic lipase sparse Secondly, they have been shown to

produce a small, soluble protein from the calin family Lipocalins assist in the transmission

lipo-of pheromonal chemoreception Finally, von Ebner gland proteins have been postulated to be involved in the transduction of taste

Taste Chemosensory stimulation of these

taste receptors occurs when saliva mixed with molecular food particles washes over the different taste buds within the papillae.3 Humans are able to distinguish fi ve taste qualities: sour, salty, bitter, sweet, and umami Umami is the taste associated with monosodium glutamate and certain other 5´-ribonucleotides.7 Recent studies have shown that the perception of bitter, sweet, and umami are mediated through stimulation of the GPCRs Furthermore, the action potential produced by stimulation of these receptors may

be modifi ed by members of the transient receptor potential (TRP) family of ion channels One study has shown that TRP channels may be stimulated

by temperature In fact, their results suggest that sweet foods are perceived as being sweeter when they are warm.8

Unlike bitter, sweet, and umami, sour and salty tastes are transmitted by stimulation of ion channels.7 The action potentials produced

by depolarization or hyperpolarization of these channels may be involved in the coding of taste.7

For more information on gustatory physiology, the reader is referred to Chapter 38, “Olfaction and Gustation.”

FLOOR OF THE MOUTH

The fl oor of the mouth is a muscular sling formed primarily by the paired mylohyoid muscles

The muscles arise from the medial surface of the mandible and extend toward the midline where they insert with muscle fi bers from the opposite side, forming a midline raphe The pos-terior most aspect of the mylohyoid musculature inserts into the body of the hyoid bone The ante-rior belly of the paired digastric muscles bound the sling inferiorly A majority of the subman-dibular gland also lies beneath the mylohyoid muscles A smaller portion of the gland curves around the posterior border of the muscle and lies above it, along with the sublingual gland, the lingual and hypoglossal nerves and the tongue vasculature Medial to the nerves and vessels lie the paired geniohyoid muscles The geniohyoid muscles arise from the mental spine and inter-nal surface of the mandible and insert onto the hyoid bone, lateral to the midline Covering the structures superior to the mylohyoid is a layer

of superfi cial cervical fascia There is a potential space between the fascia and the mylohyoid mus-cle An abscess in this potential space is known

as Ludwig angina and is considered a potentially life threatening airway emergency

All of the muscles that combine to form the

fl oor of the mouth, including the digastric cles, mylohyoid muscles, stylohyoid muscles, and the geniohyoid muscles elevate the hyoid bone and assist in swallowing

mus-Table 1 Relationship of the Branchial Arches and Their Nerves to the Sensation of the Tongue

Neural Branch Cranial Nerve Branchial Arch Sensory Modality Served

Figure 2 Diagram of the nerves

serving the sense of taste on the tongue and surrounding regions.

CHAPTER 63 / Anatomy and Physiology of the Oral Cavity 771

BONES AND DENTITION OF THE ORAL

CAVITY

The oral cavity is surrounded by bone on its

external surface as well as superiorly The bony

structures that compose a portion of the oral

cav-ity include the mandible, the alveolar and palatine

processes of the maxilla and the palatine bones

The hard or osseous palate separates the nasal

cavity from the oral cavity It is a bony plate

formed by the alveolar and palatine processes of

the maxilla and the palatine bones (Figure 4) The

alveolar process of the maxilla is the most inferior

aspect of the maxilla and contains the maxillary

dentition The alveolar process articulates with

the horizontal or palatine processes of the

max-illa medially at the level of the second and third

molars The alveolar process is formed by the

palatine processes of the maxilla anteriorly and

the horizontal plates or horizontal lamina of the

palatine bones posteriorly The suture line that

fuses these two bones lies approximately at the

level of the second and third molar interspace

This suture line is in the transverse plane There

is also a longitudinal suture that fuses the

respec-tive horizontal lamina medially Bony ridges or

bulges sometimes develop along the longitudinal

suture line and are known as torus palatinus An

additional suture is often visible in young people

This is the palatine raphe or suture between what

was once the premaxillary part of the maxilla and

the maxillary palatine processes It is the site of

fusion of the median and lateral palatine processes

during embryonic development The midline

junction of these two sutures is marked by the

incisive foramen, also known as the incisive fossa

The incisive foramen separates the primary palate

anteriorly from the secondary palate posteriorly

The incisive foramen is one of several

open-ings in the hard palate It is the opening of the

incisive canal that transmits the nasopalatine nerve and the terminal branch of the sphenopal-atine artery Other openings in the hard palate include the greater and lesser palatine foramina

The greater palatine foramen is the opening of the greater palatine canal It is located on the lat-eral border of the palate, at approximately the level of the upper third molar The canal trans-mits the greater (anterior) palatine nerve and the greater palatine artery After exiting the foramina, branches of the nerve and artery run anteriorly

in two grooves on the palate The lesser tine foramina are situated posterior to the greater palatine foramina, at the edge of the hard palate

pala-The foramina transmit the lesser palatine nerves and arteries

The hard palate is covered by a layer of mucosa that is fi rmly adherent to the underly-ing periosteum The mucosa contains numerous minor salivary glands As is evident from patients with cleft palates, the palate is vital in the process

of swallowing and in speech articulation

As with the palate, the other skeletal component of the oral cavity, the mandible, is

crucial to oral cavity function The mandible is the most prominent bone surrounding the oral cavity and forms the inferior part of the face It is the strongest and largest of the facial bones

The different parts of the mandible are the body (horizontal part), the angle, and the ramus (verti-cal part) The two sides are fused embryologically

at the midline, an area known as the symphysis

At the anterior most aspect of the symphysis is the mental protuberance, a triangular bony prom-inence The ramus ends in two bony projections

The condylar process is on the posterior aspect of the ramus The coronoid process is anterior to the condylar process and separated by the mandibu-lar notch The lateral pterygoid muscle inserts on the pterygoid fovea on the neck of the condylar process A portion of the temporalis inserts on the coronoid process Other muscles that attach to the mandible include the masseteric, medial ptery-goid, genioglossus, geniohyoid, the mylohyoid, and the anterior bellies of the digastric muscles

The masseter attaches to the lateral aspect of the mandibular angle and ramus whereas the medial pterygoid inserts on the medial surface of the angle and ramus; together they form a muscular sling around the mandible The bone of the man-dibular angle may be slightly raised on either or both the lateral and medial aspect, known as the masseteric tuberosity and pterygoid tuberosity, respectively The genioglossus and geniohyoid insert on the mental spine (genial tubercle) The mylohyoid attaches to the mylohyoid line, a line that runs up and back from the sublingual fossa

The anterior belly of the digastric attaches at the digastric fossa

The mandible has multiple other bony grooves, markings, and foramina On the medial surface of the mandible, in addition to the mental spine, digastric fossa and mylohyoid line can be found the sublingual and submandibular fossae, the mylohyoid groove and the mandibular fora-men The mylohyoid groove carries the mylo-hyoid nerve and vessels anteriorly and inferiorly after they exit from the mandibular foramen The sublingual and submandibular fossae shield the respective salivary glands Externally on the body

of the mandible is the oblique line, the mental foramen, and the mental protuberance The mental foramen is the terminal aspect of the mandibular canal, a bony canal that starts at the mandibular

Figure 3 Taste bud demonstrating

the relationship of the taste pore to the oral cavity Afferent nerve fi bers

go to several different types of cells.

Figure 4 The hard palate and its

divisions Permanent teeth 1 through

16 are shown.

772 PART IV / Pediatric Otorhinolaryngology

foramen and courses through the ramus and body

carrying the inferior alveolar nerve and vessels

The mental foramen is located along a vertical

line through the second and third premolar

inter-space Upon exit through the foramen, the nerve

is known as the mental nerve and provides

sen-sory innervation to the chin and lower lip

Similar to the maxilla, the mandible has a

bony ridge known as the alveolar process The

maxillary and mandibular alveolar processes

sup-port dentition Although teeth are not truly bone,

they are formed from dentine, a modifi ed bone,

and will be included in this section for the sake of

completeness

Deciduous teeth generally begin eruption

around 6 to 8 months of age and are complete by

age 24 months There are a total of 20 deciduous

teeth (two medial incisors, two lateral incisors,

two canines, two fi rst molars, and two second

molars on both the maxillary and mandibular

arches.) The teeth are labeled from A to T,

start-ing with the right maxillary second molar (A)

across the maxilla to the left maxillary second

molar (J) down to the left mandibular second

molar (K) and across the mandible, ending at

the right mandibular second molar (T)

Decidu-ous dentition is generally shed and replaced by

permanent dentition between the ages of 6 and

12 years Permanent dentition consists of a total

of 32 teeth (two medial incisors; two lateral

inci-sors; two canines; two fi rst and second premolars;

and two fi rst, second and third molars in both the

maxilla and mandible) These teeth are labeled in

similar fashion to the deciduous teeth, starting

with the right maxillary third molar and ending

with the right third mandibular molar Unlike

deciduous teeth, however, permanent teeth are

labeled from # 1 to # 32

BLOOD SUPPLY TO THE ORAL CAVITY,

PHARYNX, AND TONSILS

The blood supply to the oral cavity, pharynx,

and tonsils is derived primarily from the

exter-nal carotid artery (ECA) and its many branches

The artery originates at the bifurcation of the

common carotid, passing superiorly in the neck,

deep to the posterior belly of the digastric and

the stylohyoid muscle, paralleling the ramus of

the mandible The branches which primarily

supply the oral cavity, pharynx, and Waldeyer

ring include the ascending pharyngeal, lingual,

facial (external maxillary), internal maxillary,

and superfi cial temporal arteries The ascending

pharyngeal artery arises from the posterior

sur-face of the ECA and supplies several branches

to the pharynx, palate, and tonsils The lingual

and facial arteries arise from the anterior surface

of the ECA The lingual artery and its branches

supply the tongue and fl oor of mouth The facial

artery has multiple branches including the

ascend-ing palatine, tonsillar branches, branches to the

submandibular gland, the submental artery and

branches to the masticator muscle As the names

of the branches imply, the external maxillary

supplies the palate, tonsils, submandibular gland, submental space, and masticator muscle Finally, the two terminal branches of the ECA, the inter-nal maxillary artery (IMAX) and the superfi cial temporal artery arise within the substance of the parotid gland and provide small branches to the pharynx and tonsils The many blood vessels allow for collateral circulation to the entire head and neck area in the event that one or more ves-sels are injured or surgically ligated

The blood supply of the tonsils is derived from multiple vessels: the ascending pharyngeal artery, tonsillar branches of the external maxil-lary artery, the tonsillar branch of the dorsal lin-gual artery, and the descending palatine artery from the IMAX (Figure 5) The tonsillar branch

of the dorsal lingual artery, the ascending tine branch of the external maxillary artery, and the tonsillar branch of the external maxillary are typically found at the inferior pole The superior pole is supplied by the ascending pharyngeal artery and the descending palatine artery

pala-The venous drainage of the oral cavity, ynx, and Waldeyer ring is through multiple smaller veins to the internal and anterior jugular veins

phar-WALDEYER RING

Waldeyer ring is a ring of lymphoid tissue found

in the pharynx It is composed of the adenoid superiorly in the nasopharynx, both palatine ton-sils laterally in the oropharynx and the lingual tonsil inferiorly in the hypopharynx and posterior one-third of the tongue In addition, it includes the lateral pharyngeal bands and scattered lym-phoid follicles throughout the pharynx, particu-larly adjacent to the eustachian tubes Lymphoid tissue in this ring provides the body’s fi rst line of defense against inhaled or ingested pathogens

Waldeyer ring is involved in the production of immunoglobulins and the development of both B and T cell lymphocytes

Adenoid

The adenoid, also known as the pharyngeal sil, is on the posterior wall of the nasopharynx extending toward the eustachian tubes Unlike

ton-palatine and lingual tonsils, the pharyngeal tonsils does not contain crypts It is formed by verti-cal folds of respiratory epithelium from which extend the Arey glands There is no distinct cap-sule which surrounds the adenoid Enlargement

of the tissue can interfere with eustachian tube function and result in nasal obstruction with dif-

fi culty breathing The adenoid is discussed in Chapter 64, “Diseases of the Oral Cavity, Oro-pharynx, and Nasopharynx,” and Chapter 66,

“Sleep Apnea in Children.”

At the posterior midline of the pharynx just above the superior constrictor muscles lies a small sac-like depression known as the pharyn-geal bursa It is occasionally the site of a cystic formation known as Tornwaldt cyst

Palatine Tonsils

The palatine tonsils are dense, compact bodies of lymphoid tissue They are located within a fossa created by the palatoglossus muscle anteriorly and the palatopharyngeus muscle and superior constrictor muscles posteriorly and laterally The tonsil has a thin but distinct capsule on its lat-eral surface which is formed from condensation

of the pharyngobasilar fascia The fascia extends into the tonsil itself forming septa which allow for passage of nerves and vessels Whereas the capsule is densely adherent to the tonsillar tis-sue, it is readily separated from the underlying pharyngeal musculature Continuous with the palatoglossal arch and the tonsillar capsule is a layer of mucosa and connective tissue known as the triangular fold In rare instances a similar fold may be seen posteriorly In approximately 40%

of people, a fold of tissue known as a semilunar fold is found at the superior pole.6

The medial or free surface of the tonsil is ered by a thin layer of stratifi ed squamous cell epithelium (mucosa) Epithelial tubules extend from the surface deep into the tonsil, forming ton-sillar crypts There is some evidence to suggest that the epithelium lining the crypts is semiper-meable, allowing sampling of ingested material

cov-Although they extend from the surface, the est parts of the crypts remain stable The growing end is closest to the surface and is often narrower, preventing material from escaping once it has entered a crypt There are a total of 8 to 10 crypts per tonsil.9

deep-Tonsillectomy is one of the most common surgical procedures performed in children They are generally removed for obstructive sleep apnea

or chronic tonsillitis In children, large palatine tonsils may occupy a signifi cant portion of the oropharynx resulting in obstructed breathing and dysphagia Some individuals have chronic colo-nization of the tonsillar crypts with streptococcus and other bacteria These individuals may have frequent infections and halitosis Others may have infections which result in the accumulation of pus between the tonsillar capsule and the pharyngeal musculature, referred to as a peritonsillar abscess

or quinsy This can lead to fi brosis of the capsule

to the underlying pharyngeal musculature

Figure 5 The blood supply of the palatine tonsil.

CHAPTER 63 / Anatomy and Physiology of the Oral Cavity 773

A surgeon removing a tonsil must be

cognizant of the fact that the pharyngeal

musculature is fairly thin and that there are

numerous structures lateral to the fossa For

instance, the glossopharyngeal nerve lies on the

lateral surface of the musculature If it is injured,

it can lead to a taste disturbance affecting the

posterior one-third of the tongue Indeed, it is

not uncommon to see a transitory taste

distur-bance resulting from edema of CN IX following

a tonsillectomy.6 Other structures that may be in

close proximity include the stylopharyngeus and

styloglossus muscles, the stylohyoid ligament,

the ascending pharyngeal artery, the ascending

palatine branch of the facial artery and in rare

instances, an aberrant vertebral or tortuous

inter-nal carotid artery

Lingual Tonsil

The lingual tonsil is lymphoid tissue found in the

base of the tongue It extends from the foramen

cecum to the epiglottis Irregular folds of

lym-phoid tissue are covered by a thin layer of

strati-fi ed squamous cell epithelium which invaginates

to form small crypts The lymphoid tissue lacks

a distinct capsule or separation from the tongue

musculature, preventing complete removal

LYMPHATICS OF THE ORAL CAVITY

The oral cavity is drained by a dense network of

lymphatic vessels The most peripheral part of

the lymphatic collecting system is a collection

of avalvular capillaries with wide lumina, up to

100 µm in diameter.10 These capillaries are

sur-rounded by an elastic fi ber network which helps

to regulate fl uid and cell transport into and out of

the lymphatic channels There are both superfi cial

and deep networks which help to drain the tissues

of the head and neck The superfi cial network is

composed of avalvular capillaries and drains into

precollecting vessels found at the

mucosa-sub-mucosa junction Multiple precollecting vessels

join to drain into a lymph node Another set of

vessels, known as postcollecting vessels, carry

the lymph from the nodes to the right and left

lymphatic ducts and into the jugular veins The

lymphatic ducts drain into the jugular vein at its

junction with the subclavian vein

The highest concentration of lymph vessels

in the oral cavity are found in the fl oor of the

mouth (FOM).10 Lymphatic vessels in the FOM

drain lymph from the tongue, FOM, and

man-dibular gingival (Figure 6) Although several

smaller collecting vessels in the anterior part of

the FOM drain directly into submental lymph

nodes, drainage in the FOM primarily occurs

through collecting vessels in a direction along the

mandibular axis and into both ipsilateral and

con-tralateral submandibular lymph nodes A portion

of the ventral surface of the tongue also drains

into the submandibular lymph nodes, similar to

FOM drainage pathways The remainder of the

ventral surface of the tongue drains into the upper

jugular nodes

Understanding the lymphatic drainage of the tongue is of paramount importance in the treatment of patients with carcinoma of the tongue Although all of the lymphatic channels

in the tongue eventually drain to the deep cervical lymph nodes, the routes that these channels may take are extremely varied and can be somewhat unpredictable Lymphatic drainage may be either ipsilateral or contralateral and may or may not involve regional nodes fi rst Indeed some of the drainage pathways will skip directly to the deep cervical nodes (Figure 7)

Although drainage can be somewhat dictable, there are some general rules for lym-phatic drainage of the tongue (Figure 8) Lymph from the anterior two-thirds of the tongue, also known as the oral tongue, drains into the mar-ginal and central lymphatic vessels The mar-ginal vessels drain the outer one-third of the dorsal surface of the tongue, the lateral mar-gins of the tongue and a small portion of the edge of the ventral surface The central vessels drain the central two-thirds of the dorsum of the tongue The vessels generally run between

unpre-the two genioglossus muscles to unpre-the tal and submandibular lymph nodes Anteriorly, the dorsal surface of the tongue drains primarily

submen-to submental and midjugular lymph nodes The remainder of the tongue or the middle one-third

of the tongue, drains primarily into ular lymph nodes The vessels in the base of tongue, that area posterior to the circumvallate papilla drain into level II and III nodes in the neck The tongue contains a particularly high concentration of lymphatic vessels in both its superfi cial and deep networks with the density progressively increasing from the tip to the base

submandib-of the tongue Overall, there is a higher density

of lymphatic vessels in the mucosal layer than in the muscular portion of the tongue

Vessels in the buccal mucosa and maxillary gingiva drain inferiorly toward the FOM and posteriorly to the oropharynx A total of 8 to 10 collecting vessels drain lymph from these areas directly into the submandibular lymph nodes Lymph vessels from the hard and soft palates also drain inferiorly toward the mandibular gingiva and oropharynx

MINOR SALIVARY GLANDS

Between 600 and 1,000 minor salivary glands are found throughout the upper aerodigestive tract including the palate, buccal areas, and lips These glands have excretory ducts The highest concen-tration of minor salivary glands is found on the palate, with approximately 250 on the hard pal-ate and 150 on the soft palate.9 The glands on the palate receive parasympathetic innervation from the sphenopalatine ganglion while those in the remainder of the oral cavity and oropharynx are innervated by parasympathetic fi bers from the lin-gual and glossopharyngeal nerves These glands contribute to the overall production of saliva

Figure 6 Superfi cial lymphatic drainage patterns of the

fl oor of the mouth.

Figure 7 Drainage pattern of the upper jugular efferent

lymphatics demonstrating a bypass of the submandibular nodes.

Figure 8 Lymphatic drainage routes from the tongue.

774 PART IV / Pediatric Otorhinolaryngology

repositioned within the oral cavity and held anterolaterally along the hard palate by the tongue The food bolus must be the right size, consistency and temperature before initiating the oral transit phase Once the bolus is ready to be swallowed, the tongue propels the entire bolus posteriorly into the oropharynx with sequential supero-posterior movements The sequential tongue movements initiate the pharyngeal refl ex and pharyngeal phase of swallowing

The pharyngeal phase is characterized by multiple, simultaneous actions including velo-pharyngeal closure, laryngeal elevation, contrac-tion of the pharyngeal constrictor muscles, and cricopharyngeal relaxation These actions are refl exive and associated with a temporary apnea, which in adults may last anywhere from 0.5 to 10.02 seconds.12 This is followed in rapid suc-cession by superior and anterior movement of the hyoid bone and laryngeal elevation and closure

The arytenoids cartilages closely approximate the epiglottis Once the bolus has passed, the aryte-noids separate from the epiglottis and the hyoid returns to its resting position Breathing is once again initiated The bolus is propelled through the pharynx and into the esophagus by contraction

of the three pharyngeal constrictor muscles and relaxation of the cricopharyngeal muscle Relax-ation of the cricopharyngeus allows for passage

of the bolus into the esophagus and the start of the fi nal stage of swallowing The esophageal phase is also an involuntary phase The bolus is transmitted to the stomach by peristalsis of the esophageal musculature Additional information

on swallowing is contained in Chapter 82, ing of the Larynx, Trachea, and Esophagus,” and Chapter 85, “Esophagology.”

“Imag-REFERENCES

1 Tachimura T, Ojima M, Nohara K, et al Change in toglossus muscle activity in relation to swallowing volume during the transition from the oral phase to the pharyngeal phase Dysphagia 2005;20:32–9.

2 Linden RWA Taste Br Dent J 1993;175:243–53.

3 Hadley K, Orlandi RR, Fong KJ Basic anatomy and iology of olfaction and taste Otolaryngol Clin North Am 2004;37:1115–26.

4 Spector AC, Travers SP The representation of taste quality

in the mammalian nervous system Behav Cogn Neurosci Rev 2005;4:143–91.

5 Sbarbati A, Crescimanno C, Osculati F The anatomy and functional role of the circumvallate papilla/von Ebner gland complex Med Hypotheses 1999;53:40–4.

6 Hollingshead WH Anatomy for surgeons The Head and Neck, 3rd edition Philadelphia: JB Lippincott Co; 1982.

7 Huang L, Cao J, Wang H, et al Identifi cation and tional characterization of a voltage-gated chloride channel and its novel splice variant in taste bud cells J Biol Chem 2005;280:36150–7.

8 Liman E Thermal gating of TRP ion channels: Food for thought? Sci STKE 2006;326:pe12.

9 Lowry LD, Onart S Anatomy and physiology of the oral cavity and pharynx In: Snow JB, Ballenger JJ, editors Ballenger’s Otorhinolaryngology Head and Neck Surgery, 16th edition

Hamilton, Ontario: BC Decker, Inc; 2003 p 1009–19.

10 Werner J, Dunne AA, Myers JN Functional anatomy of the lymphatic drainage system of the upper aerodigestive tract and its role in metastasis of squamous cell carcinoma Head Neck 2003;25:322–32.

11 Dodds MW, Johnson DA, Yeh CK Health benefi ts of saliva:

A review J Dent 2005;33:223–33.

12 Martin-Harris B, Brodsky MB, Michel Y et al Breathing and swallowing dynamics across the adult lifespan Arch Otolar- yngol Head Neck Surg 2005;131:762–70.

PHYSIOLOGY

The oral cavity is involved in two main

func-tions: speech and swallowing A third function,

production and excretion of saliva, also occurs in

the mouth and upper aerodigestive tract

Salivary Production and Regulation

Saliva is produced by the paired parotid,

sub-mandibular and sublingual glands as well as the

numerous minor salivary glands The average

per-son produces 1.5 L of saliva daily.9 Unstimulated

whole saliva fl ow is estimated to be 0.33 to 0.65

mL/min.9 This can increase to 1.7 mL/min in the

stimulated state The major contributor to

unstim-ulated salivary fl ow is the submandibular gland

(69%) Although to a lesser degree, the parotid

glands (26%) and sublingual glands (5%) also

contribute to total unstimulated salivary fl ow It is

interesting to note that subjective sensation of dry

mouth in patients on anticholinergic medications

is not reported until resting salivary fl ow decreases

by 40 to 50% of initial values.11 Unstimulated and

stimulated salivary fl ow may be altered by many

factors including age, hormones, systemic disease

states, circadian rhythms, diet, mastication,

hydra-tion, and drugs.9,11 The largest volumes of saliva

are secreted in response to cholinergic

stimula-tion Drugs, especially anticholinergic drugs,

may therefore result in a decrease in salivary

fl ow Similarly, age has been shown to produce

a decrease in salivary fl ow.11 Disease states such

as diabetes are associated with decreased salivary

fl ow However, it is unclear as to whether this is

the result of the disease itself or of the

medica-tions used as treatment By contrast, mastication

has been associated with an increase in salivary

fl ow In fact, one study demonstrated that

chew-ing four pieces of sugar-free gum daily for a total

of 8 weeks resulted in an increase in basal fl ow

of whole saliva.11 Furthermore, chewing

sugar-free gum has been shown to stimulate saliva and,

thereby, enhance remineralization of teeth.11

The composition of the saliva secreted by the

three major salivary glands varies somewhat in

that the parotid glands produce a more serous

saliva while the submandibular glands produce

a higher mucin containing saliva Hence, high

mucin containing submandibular saliva makes

up a greater proportion of resting saliva, whereas

parotid saliva composes a greater percentage of

stimulated saliva The more serous, highly

buff-ered saliva produced by the parotid protects the

oral cavity from the detrimental effects of acid

and is secreted principally upon stimulation by

eating Similarly, the unstimulated secretion of

submandibular saliva has a higher mucin

con-tent to provide continual oral comfort through

lubrication The chemical composition of saliva

is complex and contains a myriad of proteins and

minerals including amylase, statherin, histatins,

mucins, lysozyme, lactoferrin, peroxidases,

secretory IgA, proline-rich proteins, thiocyanite,

salts, gases, and other organic substances.9,11 It

initially begins as an isotonic plasma-like fl uid

secreted by acinar cells within the salivary gland

that undergoes active reabsorption of Na+ and Cl−

as it progresses through the duct resulting in a

fi nal product that is hypotonic

Saliva has many important functions in the oral cavity The hypotonic nature of saliva facili-tates taste The inorganic constituents of saliva such as bicarbonate and phosphate allow buff-ering while phosphate and calcium function to maintain the mineral integrity of teeth Each of the salivary proteins contributes to overall oral and systemic health in different manners Amylase aids in digestion while histatins have anticandidal effects Lactoferrin, lysozyme, peroxidases, and IgA all have antibacterial effects Mucins provide lubrication and help to protect the esophagus in gastroesophageal refl ux disease Statherins aid

in the maintenance of dentition, and proline-rich proteins protect the teeth from the detrimental substances in the human diet Indeed, saliva has been credited with numerous functions including lubrication of the oral cavity, taste, digestion, and protection against infection Although commonly believed to prevent caries, quantitative studies of saliva’s effect on caries have been inconclusive.11Saliva has, however, been shown to regulate the

of a malignancy or other lesion Speech tion is discussed in Chapter 73, “Assessment of Vocal Function,” and Chapter 74, “Disorders of Speech and Language.”

produc-Swallowing

Swallowing is generally divided into three phases: the oral phase, the pharyngeal phase, and the esophageal phase The oral phase is further subdivided into the oral preparatory phase and the oral transit phase During the oral prepara-tory phase, ingested food is mixed with saliva and formed into a bolus by mastication The food bolus is contained within the oral cavity ante-riorly by sealing the lips and holding the cheek musculature close to the teeth Posteriorly, the soft palate contacts the tongue preventing the bolus from entering the pharynx too soon As

a person chews, the food bolus is constantly

Diseases of the oral cavity, oropharynx, and

naso-pharynx are among the most commonly seen

dis-orders in pediatric otolaryngology Although each

subunit is anatomically distinct, the entire area

may be conceptualized as a single functional unit

(Figures 1, 2, and 3) These areas have

contigu-ous anatomy and are subjected to the same

caus-ative factors of disease The oral cavity is defi ned

anteriorly by the vermilion border and posteriorly

by the circumvallate papillae and junction of the

hard and soft palate The oral cavity includes the

lips, oral tongue, fl oor of mouth, maxillary and

mandibular alveoli, hard palate, gingiva, and

buc-cal mucosa The oropharynx extends posteriorly

from the oral cavity to the valleculae Structures

of the oropharynx include the tongue base,

pala-tine and lingual tonsils, soft palate, and uvula

The nasopharynx is the space bounded by the

posterior part of the nasal cavity and skull base to

the level of the posterior surface of the soft

pal-ate This includes the adenoid, eustachian tubes,

and fossae of Rosenmuller Functionally, these

portions of the pharynx contribute to speech,

swallowing, and respiration This chapter will

address common pediatric diseases of the oral

cavity, oropharynx, and nasopharynx

DISEASES OF THE TONSILS AND

ADENOID

Lymphatic tissue of Waldeyer ring in the

naso-pharynx and oronaso-pharynx comprises the

pharyn-geal tonsil (adenoid), palatine tonsils, and lingual

tonsil There has been much historic debate

regarding indications for and cost-effectiveness of

adenotonsillectomy Currently, much of the

con-troversy exists in the fi eld of pediatric obstructive

sleep apnea (OSA) and sleep disordered

breath-ing Chapter 66, “Sleep Apnea in Children,”

contains a discussion of pediatric OSA

Indica-tions for tonsillectomy with or without

adenoid-ectomy are listed in Table 1

Adenotonsillar Hypertrophy

Acute and chronic upper airway obstruction due

to adenotonsillar hypertrophy is a common chief

complaint faced by pediatricians and

otolaryn-gologists The relative overgrowth of lymphoid

tissue to skeletal growth during ages 3 to 8 years

may initiate symptoms such as snoring, mouth

breathing, apnea, and dysphagia These toms may be chronic or may be acutely exacer-bated by viral or bacterial pharyngitis Further history may reveal snorting, gasping, hyponasal speech, restless sleep, enuresis, growth distur-bance, and even failure to thrive Physical exam-ination may reveal tonsillar hypertrophy, and endoscopy or lateral soft tissue radiographs may

symp-confi rm adenoid hypertrophy Lymphoid trophy and relaxation of the pharyngeal mus-culature during sleep increases the obstruction Children with craniofacial anomalies or neuro-muscular disorders are more susceptible to this process To confi rm sleep apnea, polysomnogra-phy (PSG) must be performed During PSG, the frequency of apneas, hypopneas, and arousals

hyper-Diseases of the Oral Cavity, Oropharynx and Nasopharynx

Kenny H Chan, MD

Vijay R Ramakrishnan, MD

64

Figure 1 Anatomy of the pharynx.

Figure 2 Anatomy of the nasopharynx.

776 PART IV / Pediatric Otorhinolaryngology

are measured The number and degree of oxygen

desaturations are also recorded Other factors are

monitored to determine the obstructive or

cen-tral component of the respiratory disturbance

and to document associated hypercapnia or

car-diac arrhythmia Most studies use a respiratory

disturbance index (RDI) greater than one event

per hour to diagnose pediatric OSA, although

this remains a subject of controversy However,

clinical history and physical examination are

often suffi cient to infer sleep disordered

breath-ing without the need of a PSG Adenotonsillar

hypertrophy and sleep disordered breathing have

become one of the primary indications for

ade-notonsillectomy in children Obstructive

breath-ing in children may have detrimental long-term

neuropsychologic and cardiovascular effects

which can be reversed with surgery when

appro-priate.1 In cases of isolated adenoid hypertrophy,

a trial of nasal corticosteroids is indicated prior

to surgical intervention

Adenotonsillar Infection

Acute tonsillitis is an infectious process causing fever, sore throat, odynophagia, and malaise Oro-pharyngeal erythema, edema, and exudates may be present Associated rash or lymphadenopathy may

be present Group A beta-hemolytic streptococcal pharyngitis is discussed in further detail later in this chapter Children who experience recurrent episodes of acute tonsillitis may be considered for surgical treatment In 70% of patients, the core adenoid and tonsil tissue harbor the same pathogens, which are eradicated with adenoton-sillectomy Patients with three or more episodes

of acute pharyngitis with signifi cant associated symptoms per year may be candidates for tonsil-lectomy Chronic tonsillitis, or persistent tonsil-lar infection, occurs in older children and young adults Presenting complaints are constant throat pain, fatigue, halitosis, and expulsion of tonsil-lar debris On examination, enlarged tonsillar

crypts fi lled with debris are often visualized

Tonsillectomy is indicated in chronic tonsillitis when symptoms are severe or quality of life is affected The adenoid tissue may chronically har-bor infection or become acutely infected during respiratory tract infections or sinusitis Nasal obstruction, purulent secretions, hyponasal speech, postnasal drip, throat pain, or ear pain may be present Indirect or direct examination may reveal infl amed, exudative adenoid tissue

Acute adenoiditis is treated similarly to acute tonsillitis Clinically, adenoiditis may be diffi cult

to distinguish from sinusitis Chronic adenoiditis may be a causative factor in cases of recurrent sinusitis It has been recommended that adenoid-ectomy be performed in the child with chronic sinusitis prior to pediatric endoscopic sinus sur-gery, but its effi cacy is unknown Regardless of size, adenoid tissue may cause extrinsic eusta-chian tube dysfunction in patients with chronic

or recurrent otitis media with effusion rial colonization of the adenoid may also con-tribute to recurrent otitis media Adenoidectomy

Bacte-is recommended for children undergoing repeat tympanostomy tube placement over the age of

3 years or those undergoing primary tube ment who have complaints of nasal obstruction due to adenoid hypertrophy

place-Peritonsillar infection may occur in any age group but is most common in adolescents and young adults It is the most common complica-tion of acute tonsillitis Infection is thought to spread through the tonsillar crypts and capsule into the peritonsillar space The infection begins

as a cellulitis and progresses to an abscess, most commonly near the superior pole of the ton-sil Patients will complain of fever, odynopha-gia, unilateral sore throat, and otalgia Classic signs include a muffl ed voice, trismus, uvular deviation away from the affected side, and soft palate fullness or edema The oral airway may

be compromised, and the patient may have some diffi culty with secretions Diagnosis is usually

Figure 3 Anatomical spaces of the neck.

Table 1 Indications for Tonsillectomy +/– Adenoidectomy

Severe dysphagia Cardiopulmonary complications Unresponsive or recurrent peritonsillar abscess Tonsillitis with febrile convulsions

Biopsy needed for tissue pathology Relative indications Three or more tonsillar infections per year despite proper medical treatment

Persistent foul taste or halitosis Chronic or recurrent tonsillitis in a streptococcal carrier unresponsive to medical management

Unilateral tonsillar hypertrophy presumed to be of neoplastic origin Adapted from the American Academy of Otolaryngology-Head and Neck Surgery Clinical Indicators Compendium 1995. Figure 4 Postcontrast axial computed tomography (CT)

scan, peritonsillar abscess.

CHAPTER 64 / Diseases of the Oral Cavity, Oropharynx, and Nasopharynx 777

made clinically, although it may be diffi cult to

distinguish cellulitis from an abscess, as seen in

Figure 4 Hydration, analgesics, and antibiotics

are required If abscess formation is suspected,

needle aspiration or incision and drainage is

indicated Both have success rates greater than

90% Tonsillectomy in the acute setting can be

risky due to an increased chance for hemorrhage

Those patients who experience recurrent

infec-tions or abscesses are recommended to undergo

tonsillectomy when not acutely infected

Tonsilloliths

Tonsilloliths are collections of epithelial debris

buried in the tonsillar crypts Malodorous,

granu-lar, white or yellow calculi may be removed with

irrigation or instrumentation They generally tend

to recur and can reach sizes up to 1 cm

Unilateral Tonsillar Enlargement

In the routine examination, it is not

uncom-mon for an asymptomatic patient to have the

appearance of unilateral tonsillar hypertrophy

In most cases, the tonsil is situated medially in

the tonsillar fossa, giving the illusion of a larger

tonsil In other cases, unilateral infection may

cause an enlarged tonsil Rarely is there in

under-lying malignancy causing unilateral tonsillar

enlargement in the pediatric population.2 Most

studies recommend watchful waiting unless there

is heightened suspicion for malignancy in the

his-tory or physical examination, particularly in the

presence of constitutional symptoms

Neoplasm

Nasopharyngeal carcinoma and non-Hodgkin

lymphoma may present in the nasopharynx as a

painless mass that causes nasal obstruction,

rhi-norrhea, epistaxis, or serous otitis media Proper

diagnosis and staging requires biopsy and

com-plete radiographic evaluation Hodgkin

lym-phoma rarely presents in Waldeyer ring but rather

as cervical or supraclavicular adenopathy

Trans-plant-associated lymphoproliferative disorder is

characterized by a spectrum of clinical and

his-tologic entities including lymphomas Head and

neck manifestations include a

mononucleosis-like syndrome characterized by constitutional

symptoms, cervical lymphadenopathy,

pharyn-gitis, and tonsillar enlargement with or without

obstructive symptoms

Rhabdomyosarcoma is the most common soft

tissue malignancy of childhood It is a highly

aggressive, primitive mesenchymal tumor which

presents with local symptoms The head and neck

is the most frequent site of origin, where it often

presents in parameningeal regions Although

outcome is most closely tied with clinical

stag-ing, multimodality treatment using surgery,

chemotherapy, and radiotherapy offers the best

chance for survival in patients with

rhabdomyo-sarcoma when the tumor presents in an operable

location.3

The oral cavity and oropharynx contain up to

1,000 minor salivary glands Salivary gland

neo-plasms in children are rare Most salivary gland neoplasms in children are hemangiomas or lymph-angiomas Benign tumors such as mixed tumors, Warthin tumor, oncocytoma, adenomatous tumors, and lymphoepithelial tumors are rare in children

Malignant salivary gland tumors include epidermoid carcinoma, adenocarcinoma, adenoid cystic carcinoma, malignant mixed tumor, and acinic cell carcinoma These are more likely to occur in the major salivary glands, that is, parotid and submandibular glands

muco-Juvenile nasopharyngeal angiofi broma (JNA)

is a highly vascular, locally aggressive tumor of the nasopharynx It accounts for only 0.05% of all tumors of the head and neck, and typically affects adolescent males The tumor originates in the sphenopalatine foramen and expands locally, causing symptoms of nasal obstruction Preop-erative embolization and surgical excision are the appropriate treatment Endoscopic approaches have proved equally effective to conventional open approaches in the majority of cases.4

Figure 5 shows an axial view of an extensive, locally destructive JNA JNAs are discussed in greater detail in Chapter 96, “Neoplasms of the Nasopharynx.”

Surgical Technique: Adenotonsillectomy

Many techniques have been used over the years for removal of the tonsils and adenoid The gener-ally accepted technique for tonsillectomy consists

of dissection in the subcapsular plane with a knife

or electrocautery under general anesthesia This dissection may also be achieved with a harmonic scalpel or laser Hemostasis is achieved with elec-trocautery, suture ligation, and topical thrombin

The adenoid is most frequently removed with an adenoid curette or may be vaporized with elec-trocautery

The patient is intubated and placed in the supine position with a roll under the shoulders

Perioperative corticosteroids are administered for antiemetic effect if not contraindicated A mouth gag is inserted for proper exposure of the oropharynx The palate is palpated to ensure an intact palate is present Adenoidectomy is gen-erally performed fi rst unless tonsillar hypertro-

phy prevents easy access to the nasopharynx Adenoidectomy is contraindicated in the pres-ence of a cleft palate or a submucous cleft If obstructive sleep apnea occurs in a child with a submucous cleft, only the superior adenoid tissue should be removed accurately and the electrocau-tery method is preferred to assure velopharyngeal closure One or two urinary catheters are used to retract the soft palate and the adenoid is visual-ized with a mirror Adenoidectomy can be per-formed with an adenoid curette, suction electro-cautery, or powered instrumentation Care should

be taken to stay away from the eustachian tube orifi ce and torus tubarius to prevent scarring and iatrogenic eustachian tube dysfunction

Tonsillectomy is performed in the following fashion The superior pole of the tonsil is grasped and retracted medially with an Allis clamp The mucosa of the anterior tonsillar pillar is incised and the plane of the tonsillar capsule is identifi ed

Dissection continues in this plane with cautery or using the cold technique, as the tonsil

electro-is retracted medially The inferior attachment to the lingual tonsil is then divided with electrocau-tery Care is taken to preserve normal mucosa of the anterior and posterior tonsillar pillars A Hurd retractor may be used to aid in visualization of the tonsillar fossa Hemostasis is achieved using electrocautery or suture ligature The oropharynx and nasopharynx are irrigated and observed for hemostasis An orogastric tube is passed and gas-tric contents are suctioned to limit postoperative nausea and emesis

Recent trends in the surgical techniques for tonsillectomy include both new instrumentation and subtotal tonsillectomy New instrumentations that have undergone rigorous clinical trials include the radiofrequency and microdebrider methods

The revival of subtotal tonsillectomy is partly driven by the improved postoperative pain profi le

of children who have undergone this procedure and is also driven by the easy adaptation of the newer surgical instruments The radiofrequency instrumentation is utilized for both total and sub-total tonsillectomy Although the pain profi le is improved signifi cantly using these instruments and the subtotal technique, continued studies are needed to monitor the cost benefi t of such tech-niques and the long-term sequelae of performing subtotal tonsillectomy in terms of tissue regrowth and eradiation of streptococcal disease

Dehydration, odynophagia, and otalgia are common in the postoperative period Occasion-ally, children will need intravenous hydration until adequate oral intake can be maintained Antibiotics in the postoperative period may aid marginally in return to normal activity, but recent metaanalyses show that their use does not appear to decrease postoperative pain.5,6 Post-tonsillectomy hemorrhage is the most common complication, occurring in approximately 2 to 5%, and should be taken seriously Some can be treated with observation; some will need to be controlled in the operating room Risk of hemor-rhage is higher in patients on aspirin therapy or those with bleeding disorders Hypernasal speech

Figure 5 Postcontrast axial computed tomo graphy (CT)

scan, pediatric juvenile nasal angiofi broma.

778 PART IV / Pediatric Otorhinolaryngology

is common in the postoperative period, but

last-ing velopharyngeal insuffi ciency followlast-ing

ade-noidectomy is uncommon and estimated to occur

in 1:2,000 cases Treatment for this

complica-tion includes speech therapy, or surgical creacomplica-tion

of a pharyngeal fl ap Nasopharyngeal stenosis

can occur with the use of extensive cautery with

the KTP laser or with extensive resection of the

posterior tonsillar pillars Obstructing scar

tis-sue forms from the soft palate to the posterior

tonsillar pillars or posterior pharyngeal wall at

times causing obstructive sleep apnea Treatment

consists of corticosteroid injection, lysis of scar

bands, stent placement, and rotation or

advance-ment fl aps

INFECTIOUS DISEASES OF THE ORAL

CAVITY AND OROPHARYNX

Infections of the oral cavity and oropharynx are

common These infections may be isolated to the

head and neck or may represent a part of a

sys-temic disease process Recognition of the clinical

pattern of infections and distinction of these from

other patterns of disease, are important clinical

skills leading to proper treatment

Viral infections of the oral cavity and

oro-pharynx are among the most common reasons

patients seek medical care Viral pharyngitis is

a syndrome of sore throat with a variety of other

symptoms including fever, cough, and

conges-tion Many viruses can cause pharyngitis, for

example, coxsackie virus, rhinovirus, adenovirus,

infl uenza, parainfl uenza, coronavirus,

enterovi-rus, and respiratory syncitial virus Viral studies

are usually not necessary, and treatment is

symp-tomatic Mononucleosis caused by the

Epstein-Barr virus is discussed in Chapter 42, “Etiology

of Infectious Diseases of the Upper Respiratory

Tract.”

Herpangina is a common viral infection of

young children that resembles bacterial

pharyn-gitis The etiologic agent is usually coxsackie

A or B virus, but other enteric viruses may cause

a similar clinical presentation The peak incidence

is during the summer and fall seasons Symptoms

usually consist of severe sore throat, fever, and

malaise Severe erythema, vesicles, and superfi

-cial ulcerations may be present in the posterior

aspect of the oropharynx The disease is usually

self-limited, and treatment is aimed at

symptom-atic relief Coxsackie A virus is also the pathogen

in hand-foot-and-mouth disease This syndrome

is similar to herpangina, except that the oral

cav-ity is more frequently involved than the

orophar-ynx, and vesiculopapular lesions erupt on the

palms and soles Herpes simplex infections may

present in one of two ways Primary herpetic

gin-givostomatitis is common in the young child; it

begins with a prodrome of fever and malaise, with

subsequent onset of painful, erythematous oral

vesicles The vesicles rupture within 24 hours,

leaving coalescent ulcerations that may form a

gray pseudomembrane over the oral cavity

Dif-fuse lymphadenopathy is almost always present

Diagnosis may be made by viral studies or biopsy

The virus may remain dormant in the patient’s neuronal ganglia for life and may be activated

to cause a secondary herpetic infection ing a burning sensation and vesicular eruption in the oral cavity It is termed herpes labialis when the lips are involved Precipitating factors include stress, systemic illness, fever, sunlight, bacterial infection, and immunodefi ciency Treatment is symptomatic with spontaneous resolution occur-ring within 2 weeks Some studies demonstrate a benefi t from antiviral therapy

consist-Herpes zoster infection presents as a

pain-ful, vesicular eruption over the distribution of a branch of the trigeminal nerve It usually occurs

in older patients as a reactivation of dormant varicella virus in the neurosensory ganglia Treat-ment consists of antiviral therapy

The German measles (rubella) virus infection

is uncommon in the immunized population but

is a potentially serious systemic infection acterized by cough, coryza, conjunctivitis, and

char-maculopapular rash The measles (rubeola) virus

produces a similar though more severe clinical course distinguished by the initial appearance before the rash of red spots with central bluish white specks on the buccal mucosa known as Koplik spots Infectious complications such as otitis media or pneumonia can occur due to tem-porary immunosuppression following the disease

Treatment of measles involves vitamin A mentation and human immunoglobulin in addi-

supple-tion to supportive measures Cytomegalovirus,

also a member of the herpes family of viruses, infects immunocompromised patients Infections are characterized by large mucosal ulcers, exuda-tive pharyngitis, and cervical lymphadenopathy

The disease presents similarly to mononucleosis,

and treatment is symptomatic Recurrent tory papillomatosis is a disorder caused by the

respira-human papilloma virus and is characterized by the formation of exophytic, caulifl ower-like masses

Papillomas may form in the airway or the oral cavity, specifi cally on the soft palate or tongue

Surgical excision by cold knife, electrocautery, powered instrumentation, or laser is the standard

of care Recurrences in the oral cavity and pharynx are uncommon after excision, but the recurrence rate is substantially higher in the air-way Recent studies demonstrate an improvement

oro-in disease severity and regrowth with repeated intralesional injection of mitomycin or cidofo-vir in selected patients, although clear evidence from randomized, controlled, prospective studies

is lacking

Bacterial pharyngitis is similar to viral yngitis in its presentation but more commonly is associated with malaise, headache, chills, nausea, vomiting, and abdominal pain Group A strep-tococcus (GAS) is the most common cause of bacterial pharyngitis

phar-Other causes of bacterial pharyngitis are addressed in Chapter 42, “Etiology of Infec-tious Diseases of the Upper Respiratory Tract.”

Physical fi ndings consistent with, but not nostic for, GAS include pharyngeal erythema

diag-and exudates, palatal petechiae, diag-and tender cal lymphadenopathy Throat culture is consid-ered the gold standard for detection of GAS, but there is a 5 to 10% false negative rate and there are many GAS carriers who will be falsely posi-tive The majority of rapid detection kits avail-able have a high specifi city (95%) and a sensi-tivity of between 70 and 90% compared with conventional culture on sheep blood agar White blood cell count, erythrocyte sedimentation rate, and C-reactive protein have low positive predic-tive values and are not diagnostic of bacterial pharyngitis Antibody titers do not have a role in acute streptococcal infection Treatment consists

cervi-of antibiotics and supportive care Scarlet fever

or scarlatina is an acute exanthematous disease caused by streptococcal pharyngeal infection and production of an erythrogenic toxin The compli-cations of streptococcal tonsillopharyngitis may

be classifi ed as suppurative and nonsuppurative

The nonsuppurative complications include acute rheumatic fever and poststreptococcal glomeru-lonephritis Suppurative complications include peritonsillar, parapharyngeal, and retropharyn-geal cellulitis or abscess formation

Periodic fever, adenitis, pharygitis, and thous ulcer (PFAPA) syndrome is in the dif-ferential diagnosis for recurrent pharyngitis

aph-These children are frequently seen in the trician’s offi ce or the emergency room for high fever Although cimetidine and corticosteroids purportedly are effective medical treatment, ton-sillectomy is an alternative

pedia-Fungal infection of the oral cavity is almost

always the result of Candida albicans, an

oppor-tunistic microorganism that is part of the normal oral fl ora Decrease in host immunity or altera-

tion in the oral fl ora allows Candida overgrowth

and infection Predisposing conditions include long-term antibiotic use, diabetes, corticosteroid therapy, immunosuppression, and radiation to the oral cavity Thrush, or pseudomembranous candi-diasis, is the most common type of oral candidia-sis It occurs most commonly in infants but may affect any age group It is characterized by dry, painful, white plaques covering the tongue, hard palate, and buccal mucosa These lesions may be scraped off of the raw underlying mucosa Inva-sive oropharyngeal or esophageal candidiasis

is known to occur in children with diabetes or immunosuppression Fungal smears may demon-strate hyphae, but fungal culture is needed for a defi nitive diagnosis Acute atrophic candidiasis is less common and manifests as sore throat, burn-ing of the mouth, and foul taste Erythematous, ulcerated mucosa is the characteristic appearance

Angular chelitis, painful fi ssures at the oral misure, may also be due to candida overgrowth

com-In children, a search for an underlying condition must be undertaken along with treatment of the acute fungal infection Most can be treated with

a topical antifungal agent, although recalcitrant infections may require intravenous antifungal therapy Other fungal agents that can involve the oral cavity include histoplasmosis and mucormy-cosis, which typically affect the hard palate

CHAPTER 64 / Diseases of the Oral Cavity, Oropharynx, and Nasopharynx 779

Odontogenic infections are common in

children and may lead to abscess formation or

Ludwig’s angina, a potentially life-threatening

fl oor of mouth cellulitis This process is more

commonly seen in adults with poor dentition than

in children who have shorter deciduous dental

roots Anaerobic bacteria must be considered

present in the odontogenic infection, and these

often have B-lactamase resistance Recent studies

demonstrate that high doses of

amoxillicin-clavu-lanate may overcome this resistance if penicillins

are to be used A recent study showed that greater

than 50% of deep neck infections in adults were

found to have an odontogenic source, with

Strep-tococcus viridans and Klebsiella pneumoniae as

the two most common pathogens.7 In children,

the odontogenic source of deep neck infection is

second in likelihood to an oropharyngeal source

Antibiotic therapy, abscess drainage when

pres-ent, and defi nitive treatment of the source of

infection are crucial to patient care In cases of

Ludwig’s angina, airway stability is the initial

concern, and tracheostomy may be required

Deep neck infections are discussed in Chapter 65,

“Deep Head and Neck Space Infections.”

Oral manifestations of human immunodefi

-ciency virus (HIV) infection occur in 30 to 80%

of the infected population The most common

sites of involvement are the palate, tongue, lips,

buccal mucosa, and gingiva In children, the most

common signs of HIV infection are oral

candi-diasis, diffuse parotitis, and oral ulcers Other

oral pathology that may suggest underlying HIV

infection includes xerostomia, recurrent

her-petic or aphthous ulcers, angular chelitis, hairy

leukoplakia, gingivitis and periodontitis, and

papillomas Oral hairy leukoplakia presents as an

asymtptomatic, corrugated lesion along the lateral

margin of the tongue, caused by the Epstein-Barr

virus Kaposi sarcoma presents in the oral cavity

as a pigmented macule, nodule, or hemorrhagic

lesion It may darken with age, ulcerate, necrose,

or become lobulated.8

INFLAMMATORY AND SYSTEMIC

DISEASES

Lesions of the oral cavity and oropharynx are

often presenting signs of an underlying systemic

disorder These lesions are easily accessible, and

many times are diagnostic Systemic infl

amma-tory diseases most commonly affect adults but

may occur in children and adolescents; lasting

sequelae may result from a delay in diagnosis

Kawasaki disease, or mucocutaneous lymph

node syndrome, is an acute onset, idiopathic,

multisystem vasculitis It occurs in children

under 5 years of age, with a peak incidence in

1- to 2-year-olds It is characterized by several

days of high fever, conjunctivitis, rash, erythema

and edema of the extremities, cervical

lymphade-nopathy, and multiple oropharyngeal signs These

include strawberry tongue, fi ssured lips, mucosal

erythema, and necrotic pharyngitis Up to 20% of

untreated children will develop cardiac

complica-tions, with coronary artery aneurysm being the most dangerous Kawasaki disease is the most common cause of acquired cardiac disease in children under 5 years of age Treatment consists

of intravenous gammaglobulin and aspirin

Wegener granulomatosis commonly affects the oral cavity although it is more commonly seen

in the nasal cavity and subglottic sites in teenagers

Gingival hyperplasia is common, but painful mucosal ulcerations surrounded by an erythema-tous margin may also be present Behçet syndrome

is a systemic infl ammatory disorder characterized

by recurrent oral and genital ulcers which ble apthous ulcers Ocular infl ammation, such as uveitis or iridocyclitis, aids in diagnosis Corti-costeroids, chlorambucil and acyclovir have been used for treatment Reiter syndrome classically presents as urethritis, uveitis, conjunctivitis, and arthritis in young men Superfi cial, erythematous oral ulcers with a white rim are associated with this syndrome Sjögren syndrome is a collagen vascu-lar disease that causes xerostomia, keratoconjunc-tivitis, and arthritis Labial biopsy confi rms the diagnosis by demonstrating a lymphocytic infi l-trate in the minor salivary glands Approximately 25% of patients with systemic lupus erythemato-sus will have oral cavity manifestations including xerostomia, petechiae, hemorrhagic bullae, and white mucosal keratoses

resem-Primary macroglossia may occur in roidism, acromegaly, and Beckwith-Wiedemann syndrome Secondary macroglossia may occur

hypothy-in angioneurotic edema, amyloidosis, glycogen storage diseases, neurofi bromatosis, actinomy-cosis, syphilis, tuberculosis, and in neoplastic processes Macroglossia occurs in 15 to 20% of patients with amyloidosis and can grow to mas-sive proportions Amyloidosis may also occur as nodules or polypoid lesions and can be located anywhere in the larynx or trachea Burning mouth syndrome is a local neuropathy of the tip and lat-eral aspects of a normal appearing tongue This disorder of peri- and postmenopausal women is treated with amitryptiline and clonazepam Geo-graphic tongue is an idiopathic benign migratory glossitis resulting from a loss of fi liform papillae

In this process, there are central, red, atrophic lesions on the dorsum of the tongue with a margin

of desquamating epithelium Lesions may occur

on the buccal mucosa, as well This chronic dition may persist for years and does not require treatment Fissured tongue is similar in that mul-tiple lesions occur on the dorsum of the tongue and treatment is not necessary However, these

con-fi ssures may become irritated with food particles, bacteria, or fungi Fissured tongue has been asso-ciated with Down syndrome and Melkersson-Rosenthal syndrome, a recurrent process of facial nerve palsy and facial edema Hairy tongue is

a benign disorder characterized by hypertrophy

of the fi liform papillae, which may then become colonized with pigmented bacteria Poor hygiene, tobacco use, oral antibiotics, and radiation ther-apy are predisposing factors

Aphthous stomatitis and recurrent aphthous ulcers are the most common condition affecting the

oral cavity Recent studies have demonstrated an alteration in cellular immune response as a predis-posing factor In the pediatric population, this dis-ease occurs in older children and adolescents, with

a gender predilection for females There is a hour prodrome of dysesthesia and erythema of the oral mucosa prior to appearance of an ulcer There are three categories of aphthous ulcers Minor aph-thous ulcers account for approximately 80%; these are shallow, painful ulcers of the oral mucosa cov-ered by a gray membrane and surrounded by an erythematous rim These ulcers typically affect the buccal mucosa, lips, and tongue They resolve spontaneously in approximately 2 weeks and may recur regularly in intervals Major aphthous ulcers are characterized by painful ulcerations greater than 0.6 cm in size These may occur on the soft palate, fl oor of mouth, and peritonsillar mucosa

48-Major ulcers may persist for up to 6 weeks and may also recur in regular intervals Less common are herpetiform ulcers, crops of multiple painful, pinpoint lesions These may coalesce into large, irregular ulcerations anywhere in the oral cavity

Treatment for all forms is symptomatic, with cal anesthetics or corticosteroids providing some degree of pain relief In severe cases, intralesional

topi-or systemic ctopi-orticosteroids and acyclovir may be

of some benefi t

Lichen planus is a common immune-mediated, infl ammatory disorder of the epithelial surface of the skin and mucous membrane It may occur in children and adolescents, although it is consid-ered a disease of adulthood The disease process

is a cell-mediated immune response that may be

a part of a systemic disease Lichen planus of the oral cavity is found on the tongue, buccal mucosa, and gingival margin The reticular type is more common and appears as isolated or coalescent white papules or lines known as Wickham striae

This can be symmetric and is usually tomatic An erosive type contains an ulcerative center with lines or papules at the periphery and may undergo malignant transformation Biopsy

asymp-of the periphery asymp-of a lesion provides a diagnosis

Symptomatic lesions may be treated with topical, injectable, or systemic corticosteroids

The autoimmune disorders pemphigus garis, pemphigoid, and cicatricial pemphigoid similarly affect adults more than children These conditions may be distinguished by their clini-cal, histologic, and immune characteristics All demonstrate a loss of cohesion among epidermal cells that results in accumulation of intradermal

vul-fl uid and blisters In pemphigus vulgaris, this loss

of cohesion occurs in the epidermal layer, and in pemphigoid occurs at the basement membrane Nikolsky sign, a loss of epidermis by rubbing skin or mucous membrane, occurs in pemphigus vulgaris Most cases of pemphigus vulgaris in children begin in the oral cavity Vesicles and bullae form and rupture, leaving painful ulcer-ations similar to erythema multiforme Oral lesions in pemphigoid occur in approximately 40% of patients

Erythema multiforme is an acute infl tory disorder of the skin and mucous membranes

amma-780 PART IV / Pediatric Otorhinolaryngology

that is associated with infections, autoimmune

disease, stress, and certain antibiotics It affects

males more than females and occurs mostly in

the second and third decades of life Two forms

exist Erythema multiforme minor is a

self-limited disease of minimal skin and mucosal

injury, lasting 2 to 3 weeks Erythema

multi-forme major, known as Stevens-Johnson

syn-drome, consists of hemorrhagic skin and

muco-sal lesions Target lesions consisting of a central

bulla and surrounding erythema usually begin

on the palms and soles They typically merge

and spread symetrically Oral lesions involve the

lips, tongue, and fl oor of mouth but are absent in

25% Erythema multiforme major is also

asso-ciated with systemic symptoms and purulent

conjunctivitis It is more commonly associated

etiologically with drug ingestion and can lead to

death from pulmonary involvement Diagnosis is

made clinically, and treatment involves

discon-tinuation of the causative agent, systemic

cor-ticosteroids, antihistamines, and supportive and

local care

THE NECK MASS

Pediatric patients commonly present with a chief

complaint of a new neck mass Although

malig-nancy is a concern in the pediatric population,

infectious and infl ammatory causes are much

more likely To date, there is not an established

guideline for the diagnosis of a new pediatric

neck mass The differential diagnosis is quite

dif-ferent than that of the adult population, in which

the rate of malignancy may be as high as 50%

A differential diagnosis may be generated

based upon the age of the patient, the history,

and the location and physical features of the neck

mass Table 2 illustrates the most common causes

based upon age of the patient In children, the

most common cause of neck masses is infl

am-matory lymph nodes from viral or bacterial

infections Congenital neck masses are also

com-mon Primary malignancy, such as lymphoma

and leukemia, may occur but are less common

In older children and young adults, congenital or

developmental lesions and salivary gland lesions are more common For adults over 40, primary or metastatic malignancy must be the fi rst consid-eration, with infl ammatory and systemic disease being of second importance

Workup consists of a thorough history and physical examination A rapidly enlarging mass suggests an infl ammatory or malignant cause

Temporal association with head and neck infection indicates an infectious or infl amma-tory origin Constitutional symptoms of fever, sweats, weight loss, and fatigue are indicative

of a systemic process such as lymphoma or mycobacterial infection Neck masses should

be assessed for size, multiplicity, character, rounding tissue changes, and the presence of bruits or thrills Lymph nodes greater than 2 cm

sur-in a child are considered abnormal, especially

if enlarging, and warrant further investigation

There is no standard guideline for diagnosis

or workup of the neck mass Imaging is often undertaken even when a diagnosis is suggested

by history and physical examination to establish the anatomy of the lesion and assist in surgical planning Ultrasound is frequently used initially

to determine if the lesion is cystic and unilocular

or multilocular CT and MR imaging provides essential information on the location that allows optimal preoperative planning If a malignancy

is suspected, chest radiography is indicated

When a diagnosis cannot be established, sional biopsy is preferred over needle aspiration

exci-to provide adequate tissue for thorough logic analysis

patho-Midline neck masses include reactive adenopathy, ranulas, thyroglossal duct cysts, and epidermoid, dermoid, teratoid, and thymic cysts

lymph-The thyroglossal duct cyst is the most common congenital neck mass, accounting for 70% of congenital neck anomalies Approximately 50%

of patients present before 20 years of age, with

a second group of patients presenting in young adulthood Treatment is surgical Lateral neck masses are most commonly reactive lymphade-nopathy, branchial arch anomalies, lymphatic malformations, major salivary gland tumors, and rarely, external laryngoceles Lymphoma may

present as a lateral, fi rm, fi xed, neck mass chial cleft anomalies may manifest as any com-bination of sinus tracts, fi stulas, or cystic masses

Bran-Depending on the embryologic origin, these anomalies may present in the external auditory canal, the tonsillar fossa, periparotid area, or the anterior or posterior cervical triangles Lymphatic malformations include lymphangiomas and cys-tic hygromas and may be either uni- or multi-locular Approximately, 75 to 80% of all cystic hygromas involve the neck and the lower portion

of the face Treatment historically has been cal, but recent studies have demonstrated ben-efi t with intralesional sclerotherapy in selected cases.9 A laryngocele or dilated laryngeal saccule may present as an external neck mass in approxi-mately 25% of cases Congenital anomalies are discussed further in Chapter 70, “Congenital Anomalies of the Head and Neck.” Discussion of diseases of the salivary glands is found in Chapter

of the fl oor of the mouth A small simple ranula may be asymptomatic, whereas larger ones can cause dysphagia or impairment of speech Sim-ple ranulas may be treated with marsupialization

or excision of the sublingual gland Recurrence rates are markedly improved when excision of the sublingual gland is performed.10 The plung-ing ranula is the less common of the two types, extending through the fl oor of the mouth into the submandibular space It presents as a soft, pain-less, ballotable, submandibular mass which may

or may not have an intraoral component Surgical treatment of the plunging ranula includes sublin-gual gland excision and evacuation of the ranula

Intralesional sclerotherapy with a streptococcal preparation, OK-432, has shown promising short-term results although long-term outcomes are yet

to be established.12

BENIGN LESIONS OF THE GINGIVA, MAXILLA, AND MANDIBLE

Several benign lesions are found in the newborn

The congenital epulis presents as a pink, lated, pedunculated mass of the anterior aspect

lobu-of the maxillary gingiva Treatment is local sion The melanotic ectodermal tumor of infancy

exci-is a fi rm, well-circumscribed, often pigmented, mass arising at the junction of the globular and maxillary processes in the fi rst 6 months of life

It may be associated with nasal obstruction and facial swelling, and the patient is treated with complete excision Epstein pearls are small keratinous cysts found on the palate or alveolus

These cysts are transient and exfoliate within a few weeks

The torus palatinus and torus mandibularis are not congenital lesions but arise after puberty

Table 2 Differential Diagnosis of a Neck Mass*

Age (yrs)

Congenital /developmental

*Does not include neurogenic or vascular masses.

CHAPTER 64 / Diseases of the Oral Cavity, Oropharynx, and Nasopharynx 781

These are asymptomatic bony growths

occur-ring in 8 to 20% of the population and do not

require treatment A classic torus palatinus is

seen in Figure 6 The pyogenic granuloma is a

smooth, soft, red, friable, pedunculated lesion

that arises as a response to trauma or chronic

irritation Treatment is local excision Fibrous

dysplasia of the monostotic type affects the

max-illa more commonly than the mandible This

disease presents as a painless swelling in the

zygoma or canine fossa that grows rapidly from

childhood to early adolescence The disease

pro-cess tends to stabilize with puberty When

cos-mesis or function is altered, conservative

resec-tion is recommended The giant cell reparative

granuloma occurs in older children and affects

the mandible more frequently than the maxilla

This tender intraoral mass can be deforming,

and the patient is treated with curettage or

exci-sion Osteomas are slow growing lesions with a

characteristic radiographic appearance; they are

normally completely asymptomatic and

treat-ment is not necessary Eosinophilic granuloma is

a benign variant of Langerhans cell histiocytosis

that may present in the mandible or skull with

fever, pain, swelling, and leukocytosis They

may occur in children or adolescents and regress

spontaneously

Benign lesions of the gingiva, maxilla, and

mandible may arise from an odontogenic source

The most common odontogenic tumor is the

odon-toma, a hamartomatous tumor of dentin, enamel,

and cementum The odontoma rarely grows large

enough to become symptomatic, and the patient

is treated by enucleation of the lesion The

amelo-blastoma is a deforming, locally aggressive tumor

that arises from tissue evolved in enamel

forma-tion It initially presents as a fi rm, painless mass

but will eventually undergo cystic degeneration

into an osteolytic, multicystic, expansile mass

Treatment is complete excision The odontogenic

myxoma is a painless mass in an older child that

is associated with eruption of permanent

denti-tion It may be locally aggressive, and the patient

is treated with wide excision of the lesion There

are a number of other rare odontogenic tumors,

including the adenoameloblastoma, cementoma,

Penetrating injury to the oropharynx requires

a more extensive evaluation than that of the oral cavity due to the intimate anatomic relationships

of the carotid artery, jugular vein, vagus nerve, sympathetic plexus, and cranial nerves IX and XII The posterolateral oropharynx is considered

an area of low resistance, with only the palatine tonsil and superior constrictor muscle protecting the carotid sheath Carotid injury is thus exclu-sively related to penetrating trauma of the lateral peritonsillar musculature.11 The internal carotid artery (ICA) is compressed between the foreign object and the skull base or second or third ver-tebra, leading to intimal dissection or thrombus formation

Lacerations anywhere in the oropharyngeal wall may violate fascial planes, allowing direct spread of salivary contents into deep neck spaces continuous with the mediastinum Gravity and negative intrathoracic pressure with inspiration facilitate the fl ow of air and secretions into these spaces The child may present with stridor, subcu-taneous emphysema, pneumothorax, and airway compromise Recommendations exist for opera-tive repair of free hanging edges, although some authors have observed equivalent outcomes with observation and repair by secondary intention

Antibiotic prophylaxis is reserved for injuries greater than 1 cm.13 Soft tissue plain radiographs

or computed tomography may suggest abscess formation, in which case operative drainage and intravenous antibiotics are indicated

A thorough history and physical examination

is imperative to rule out these rare but ing consequences Examination of the injury for depth of penetration and laterality will direct the physician toward possible sequelae The airway should be secured primarily, and then thorough

devastat-physical examination should be completed, including a complete neural and vascular exami-nation Hematoma, Horner syndrome, and tran-sient ischemic attacks are heralds of blunt ICA injury One must remember that lucid intervals of

up to 72 hours are common with blunt ICA injury, and delayed onset of progressive focal neurologic signs may arise after an initial normal examina-tion Soft tissue plain radiography is indicated in oropharyngeal injury

Suspicion for carotid injury is raised with eral oropharyngeal injury that penetrates muscle

lat-or a mechanism that provides suffi cient pressive force without mucosal penetration In children with a high suspicion of injury or non-compliant families, imaging is recommend The gold standard has been angiography, but recent evidence shows that contrast-enhanced com-puted tomography may be suffi cient.14 Computed tomography (CT) angiogram has been studied

com-in the adult population and appears to provide

a high sensitivity but mediocre specifi city for carotid injury Thus, it may be a viable option

as an initial radiographic study, with phy reserved for abnormal fi ndings on CT Mag-netic resonance angiogram (MRA) has also been shown to provide excellent detection of carotid injury.15 An outpatient treatment protocol consist-ing of serial examination has been recommended

angiogra-in cases of an asymptomatic child greater than 1 year of age with reliable parents who lives in close proximity to medical care Treatment for trau-matic oropharyngeal lacerations is summarized

in Table 3.16 Interventional or conventional rosurgical techniques have had mixed outcomes

neu-Anticoagulation with aspirin, tissue-plasminogen activator, or heparin is controversial

MISCELLANEOUS DISEASE OF THE ORAL CAVITY AND OROPHARYNX Leukoplakia

The World Health Organization (WHO) defi nes oral leukoplakia as a predominantly white lesion

of the oral mucosa that cannot be characterized as any other defi nable lesion Leukoplakia may be idiopathic or associated with tobacco smoking

It is primarily a condition of the adult tion, with a prevalence of 0.1 to 5% It is less common in children but is often found in those with candidiasis or viral infections Leukoplakia

popula-is considered a precancerous lesion; malignant transformation occurs in 2 to 6%, with an annual transformation rate of less than 1% Histologic

Figure 6 Torus palatinus.

Table 3 Assessment of Oropharyngeal Trauma

Avulsed fl ap, foreign body, gross contamination Exploration /repair + antibiotics

Adapted from reference 16.

782 PART IV / Pediatric Otorhinolaryngology

features of keratosis, infl ammation, and dysplasia

are highly variable Risk of malignancy increases

in extremely adherent lesions with abundant

ker-atosis Small studies have shown that vitamin A,

retinoids, and beta-carotene may completely

resolve the oral lesions and that retinoic acid may

prevent histological worsening Routine

follow-up and excision of the lesion in high-risk

popula-tions is recommended.17

Vitamin Defi ciency

Iron defi ciency is common in children, with oral

manifestations consisting of burning tongue,

mucosal pallor and atrophy, angular chelitis, and

hyperkeratotic mucosal lesions In adults, iron

defi ciency may be associated with esophageal

ulcerations and webs in Plummer-Vinson

syn-drome Vitamin C defi ciency, or scurvy,

pres-ents as swollen red gingiva which progresses to

hemorrhagic ulcerative gingivitis Other fi ndings

include oral petechiae, stomatitis, and

hemor-rhagic mucosal lesions Ribofl avin defi ciency

manifests as glossitis, gingivolabial pallor,

angu-lar chelosis, and a burning sensation of the oral

cavity Folate and B12 defi ciency both cause

recurrent oral ulcers and painful atrophy of the

tongue and oral mucosa Niacin defi ciency, or

pellagra, causes painful erythema and edema of

the oral mucosa and tongue, as well as angular

chelitis and necrotizing ulcerative gingivitis

Examination fi ndings may be mixed, as multiple

defi ciencies may occur simultaneously

Elemental Heavy Metal Toxicity

It is quite common to have oral signs and

symp-toms of heavy metal toxicity, as many of these are

often metabolized and secreted in saliva Lead

poi-soning is considered the most important chronic

environmental illness affecting children today In

the pediatric population, nearly every organ

sys-tem is subject to lead toxicity In children, lead

sulfi de precipitates or “lead lines” at the gingival

margin are fairly specifi c for lead poisoning

Envi-ronmental mercury toxicity has become a major

concern because of its industrial uses in fossil

fuels and agriculture It has been used historically

in dental amalgams and many medical therapies

Recent widespread exposures have occurred in

fi sh, grain, and beauty creams Otolaryngic festations of toxicity include metallic taste, sialor-rhea, and ashen-gray mucous membranes Other elements known to cause similar discoloration of the tongue and oral mucosa include arsenic and bismuth

mani-Drooling

Sialorrhea is the inability to control oral tions, usually due to dysfunction of the swallow-ing mechanism Although most commonly due

secre-to chronic nervous system impairment, many chronic disease processes may lead to this entity

Drooling can lead to further medical ailments, such as impaired masticatory function, risk of aspiration, perioral infections, and loss of fl uid, electrolytes, and proteins Nonsurgical methods

of treatment include oral motor therapy, ioral modifi cation, and oral appliances When not contraindicated, medications including choliner-gic muscarinic receptor antagonists, for exam-ple, atropine, scopolamine, or glycopyrronium bromide, appear to be effective in many cases

behav-Radiotherapy is not recommended for children because of the risk of inducing malignancy, growth retardation, xerostomia, mucositis, radia-tion caries, and osteoradionecrosis; however, this may be a reasonable treatment modality in the elderly population Surgical treatment includes parotid or submandibular duct relocation or liga-tion, sublingual duct ligation, submandibular or sublingual gland excision Duct relocation may

be effective in the initiation of the swallowing mechanism and has a role for certain patients

Bilateral sublingual and submandibular duct tion has been effective in approximately 80%

liga-of cases.18 This may be done surgically or with

a Nd:YAG laser When injected in the salivary gland, botulinum toxin inhibits acetylcholine release in the cholinergic nerve endings at neuro-secretory junctions Percutaneous injection under ultrasound guidance into the parotid and subman-

dibular glands provides a safe, minimally sive alternative that provides effect for 6 weeks

inva-to 6 months

REFERENCES

1 Chervin RD, Ruzicka DL, Giordani BJ, et al Sleep-disordered breathing, behavior, and cognition in children before and after adenotonsillectomy Pediatrics 2006;117:769–78.

2 Cinar F Signifi cance of asymptomatic tonsil asymmetry

Arch Otolaryngol Head Neck Surg 2004;131:101–3.

3 Daya H, Chan HS, Sirkin W, Forte V Pediatric coma of the head and neck: Is there a place for surgical manage- ment? Arch Otolaryngol Head Neck Surg 2000;126:468–72.

4 Pryor SG, Moore EJ, Kasperbauer JL Endoscopic versus ditional approaches for excision of juvenile nasopharyngeal angiofi broma Laryngoscope 2005;115:1201–7.

5 Dhiwakar M, Eng CY, Selvaraj S, McKerrow WS Antibiotics

to improve recovery following tonsillectomy: A systematic review Arch Otolaryngol Head Neck Surg 2006;134:357–64.

6 Burkart CM, Steward DL Antibiotics for reduction of tonsillectomy morbidity: A meta-analysis Laryngoscope 2005;115:997–1002.

7 Huang TT, Liu TC, Chen PR, et al Deep neck infection:

Analysis of 185 cases Head Neck 2004;26:854–60.

8 Reznik DA Oral manifestations of HIV disease Top HIV Med 2006;13:143–8.

9 Lee HM, Lim HW, Kang HJ, et al Treatment of ranula in pediatric patients with intralesional injection of OK-432

Laryngoscope 2006;116:966–9.

10 Zhao YF, Jia Y, Chen XM, Zhang WF Clinical review of

580 ranulas Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:281–7.

11 Hengerer A, DeGroot TR, Rivers RJ, Jr, Pettee DS nal carotid artery thrombosis following soft palate inju- ries: A case report and review of 16 cases Laryngoscope 1984;94:1571–5.

12 Hellman J, Shott SR, Gootee MJ Impalement injuries of the palate in children: Review of 131 cases Int J Pediatr Otorhi- nolaryngol 1993;26:157–63.

13 Schoem SR, Choi SS, Zalzal GH, Grundfast KM ment of oropharyngeal trauma in children Arch Otolaryngol Head Neck Surg 1997;123:1267–70.

14 Brietzke S, Jones D Pediatric oropharyngeal trauma: What

is the role of CT scan? Int J Pediatr Otorhinolaryngol 2005;69:669–79.

15 Klufas R, Hsu L, Barnes PD, et al Dissection of the carotid and vertebral arteries: Imaging with MRA AJR 1995;164:673–7.

16 Randall DA, Kang DR Current management of ing injuries of the soft palate Otolaryngol Head Neck Surg 2006;135:356–60.

17 Lodi G, Sardella A, Bez C, et al Interventions for ing oral leukoplakia Cochrane Database Syst Rev 2004;3:

treat-CD001829.

18 Meningaud JP, Pitak-Arnnop P, Chikhani L, Bertrand JC

Drooling of saliva: A review of the etiology and management options Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:48–57.

Deep head and neck space infections continue to

occur and may involve resistant microorganisms

despite the use of broad-spectrum antimicrobial

agents Easy access to imaging studies such as

computed tomography (CT) scans has improved

our diagnostic abilities in differentiation of

cel-lulitis versus abscesses of the fascial spaces of

the head and neck in children In general, patients

with cellulitis and small early, uncomplicated

abscesses may be treated with intravenous

anti-microbials whereas larger abscesses will require

incision and drainage or in selected patients

nee-dle aspiration

ETIOLOGY OF DEEP HEAD AND NECK

SPACE INFECTIONS

Deep head and neck space infections generally

fol-low the lymphatic drainage pathways Paranasal

and nasopharyngeal infections generally precede

retropharyngeal space infection Tonsillar

infec-tions precede peritonsillar and parapharyngeal

space infections Dental and gingival infections

may be the source of mandibular,

submandibu-lar, masticator, parotid, parapharyngeal, and

buc-cal space infections Abscess of the root of the

canine teeth may lead to canine space infection

Trauma to the pharynx may provide a portal of

entry for infection of the retropharyngeal,

para-pharyngeal, or visceral spaces Sialoadenitis may

lead to infection in the parotid or

submandibu-lar spaces Congenital anomalies such as

bran-chial cleft remnants, lymphangiomas, or dermoid

cysts may become infected and cause infection

of adjacent spaces Hematogenous Haemophilus

infl uenzae infection in the past often led to

buc-cal space infection, but this is now rare in the H

infl uenzae type b immunization era

It is of critical importance to determine the

original site of infection that led to the

develop-ment of a deep head and neck space infection

and to treat the patient adequately for both

pro-cesses This may include procedures such as

mas-toidectomy, sinus surgery, removal of a salivary

gland, or dental surgery For example, mastoiditis

may be complicated by bone erosion and abscess

below the mastoid cortex and into the upper neck

(Bezold abscess) and be the source of an associated

parapharyngeal space abscess (Figure 1) Both the

mastoid and deep neck space infections must be

surgically drained to adequately treat the child

If deep neck space infection occurs

repeat-edly in the same anatomic site, the presence of

a congenital anomaly such as a branchial cleft remnant should be considered For example, a third branchial cleft sinus with an opening into the pyriform sinus may be the cause of recurrent infections in the neck (Figures 2 and 3) After incision and drainage and resolution of the infec-tion, the branchial cleft anomaly should be com-pletely excised for defi nitive cure

BACTERIOLOGY AND ANTIMICROBIAL THERAPY FOR DEEP HEAD AND NECK SPACE INFECTIONS

Infections of the fascial spaces of the head and neck are often polymicrobial and include gram-positive and anaerobic microorganisms Stud-ies have also shown a considerable percentage

of gram-negative microorganisms in deep head and neck space infections in the pediatric popula-tion.1–3 In view of the presence of gram-positive, gram-negative, and anaerobic microorganisms in these infections, ampicillin-sulbactam is a good choice For patients allergic to penicillin, cefu-roxime, or clindamycin plus an aminoglycoside are good alternatives Additionally, methacil-

lin resistant Staphylococcus aureus has become

more prevalent as a cause of these infections

If a child has a serious infection and has been

exposed to methacillin resistant Staphylococcus aureus or is very ill or toxic despite ampicillin-

sulbactam, then vancomycin or linezolid may be

considered Eikenella corrodens infection may

be associated with human bites E corrodens is

resistant to clindamycin but sensitive to penicillin and cephalosporins.4,5

If incision and drainage, needle aspiration or blood or wound cultures detect a specifi c micro-organism, the antimicrobial therapy may be narrowed based on susceptibility studies

For deep head and neck space infections intravenous antimicrobial therapy is usually con-tinued for approximately 5 days Once a child has responded favorably to intravenous and/or

Deep Head and Neck Space Infections

Robert F Yellon, MD

65

Figure 1 Bezold abscess Mastoiditis with bone erosion

of mastoid cortex and abscess cavity extending into the upper neck There was an associated parapharyngeal space abscess Both the ear and neck infections required surgical therapy for resolution.

Figure 2 Computed tomography scan of the neck of a

child with recurrent deep neck infections showing an infected third branchial cleft sinus.

Figure 3 Endoscopic photograph from the child with

recurrent deep neck infections whose computed raphy scan is shown in Figure 2 The third branchial cleft sinus is seen opening into the pyriform sinus adjacent to the esophageal inlet.

tomog-784 PART IV / Pediatric Otorhinolaryngology

surgical therapy, oral therapy may be continued

for 7 to 10 days with amoxicillin-clavulanate,

cefuroxime, cefdinir, or clindamycin

DIAGNOSTIC STUDIES

Laboratory diagnostic studies include complete

blood count with white blood cell differential,

electrolytes, and urine specifi c gravity Blood,

throat, and wound cultures should be obtained

when appropriate

Radiographic studies include anteroposterior

and lateral neck fi lms If the retropharyngeal soft

tissues are wider than 7 mm or the retrotracheal

soft tissues are wider than 13 mm, then infection

in the retropharyngeal space is likely However,

unless the lateral neck fi lm is taken with the neck

in extension and during inspiration, there will be

spurious thickening of the retropharyngeal

tis-sues Air in the retropharyngeal tissues usually

indicates the presence of an abscess

CT is an excellent diagnostic tool to

differ-entiate deep neck space cellulitis versus abscess

An abscess appears as a lesion with a contrast

enhancing rim and a lucent center As can be seen

from the studies listed in Table 1,1,6–10 CT scan is

accurate (positive predictive value) for the

detec-tion of deep neck space abscess approximately

76% of the time

Although lateral neck radiography and

com-puted tomography are the most often utilized

diagnostic studies, magnetic resonance

imag-ing and ultrasonography may also be useful for

selected patients to determine the site of deep

neck space infection and whether an abscess is

present Magnetic resonance imaging and

ultra-sound also have the advantage of no radiation

exposure for the child

PRESENTATION AND TREATMENT OF

DEEP NECK SPACE INFECTIONS

Peritonsillar Space Infection

Peritonsillar space infection is the most common

deep neck space infection It is most often a

com-plication of tonsillitis Clinically, red, swollen

tonsils are seen bilaterally, usually with exudate,

and there is signifi cant swelling lateral and

supe-rior to the tonsil on one side In severe cases, the

uvula is displaced by the mass effect Although

bilateral peritonsillar space infections have been

reported, they are rare and unilateral peritonsillar

infections are seen in the vast majority of cases

Neck adenopathy is often present and more prominent on the side of the peritonsillar infec-tion Pain on opening the mouth occurs when infection and infl ammation extend to the internal pterygoid muscle in the parapharyngeal space It usually occurs in more serious peritonsillar space infections such as severe cellulitis and abscess

In most cases, if pain on opening the mouth is absent, abscess is not present Pain on opening the mouth may limit adequate examination and treatment

Peritonsillar cellulitis in an older child with adequate oral intake may be treated with oral antimicrobial agents such as those listed above whereas those with poor oral intake must be treated with intravenous antimicrobials

When severe pain, fever, signifi cant ing of the peritonsillar area, pain on opening the mouth and displacement of the uvula are present,

bulg-a peritonsillbulg-ar bulg-abscess is likely CT mbulg-ay be used

in selected patients to determine whether tonsillar abscess versus cellulitis is present when the examination is limited by pain on opening the mouth or when the child fails to improve after an initial trial of antimicrobials CT is not needed for the majority of patients, and the diagnosis can usually be made by clinical examination

peri-Peritonsillar cellulitis usually responds to microbial agents, however, peritonsillar abscess requires incision and drainage, tonsillectomy, or needle aspiration, in addition to antimicrobial ther-apy The decision to perform incision and drain-age, tonsillectomy, or needle aspiration is based

anti-on several factors If a child with a peritanti-onsillar abscess has had a history of prior peritonsillar abscess, numerous episodes of recurrent tonsilli-tis, or adenotonsillar hypertrophy with obstructive sleep apnea or if previous incision and drainage or needle aspiration were not effective, then tonsil-lectomy can be done immediately Tonsillectomy performed at the time of peritonsillar abscess is called “Quinsy tonsillectomy,” or “tonsillectomy

à chaud.” “Quinsy” is an obsolete term for tonsillar abscess, and “tonsillectomy à chaud” is derived from the French for “hot tonsillectomy.”

peri-Review of the literature shows that rent peritonsillar abscess occurs in approxi-mately 17% and recurrent tonsillitis occurs in approximately 28% of patients with peritonsillar abscess.11–16 Tonsillectomy is usually not per-formed for patients with a single episode of peri-tonsillar abscess Some surgeons have anecdotally

recur-claimed that immediate tonsillectomy for tonsillar abscess is associated with an increased risk of bleeding However, pooled data from a total of 1,169 patients who underwent immedi-ate tonsillectomy showed only a 3.5% incidence

peri-of excessive perioperative or delayed rhage.11–13,17–19 Only one of these studies showed

hemor-an increased rate of secondary hemorrhage (22%) following immediate tonsillectomy.19

Tonsillectomy may therefore be performed immediately for some patients, whereas in other patients a decision may be made to perform ton-sillectomy after an interval of approximately

6 weeks (interval tonsillectomy) Immediate tonsillectomy would be considered if there is acute severe airway obstruction or if incision and drainage has failed Immediate tonsillectomy has the advantages of having only one period of hos-pitalization and morbidity and decreasing overall time and expense Interval tonsillectomy should

be considered if the general condition of the child

is poor or the child has a coagulopathy or has taken anticoagulants

Needle aspiration has also been advocated for drainage of peritonsillar abscess but is less reliable than incision and drainage, or immedi-ate tonsillectomy Repeat needle aspiration may

be required.20,21 Even when incision and drainage are performed for peritonsillar abscess, a needle aspiration is used to locate the abscess

Retropharyngeal Space Infection

Retropharyngeal space infections usually ent with fever, dysphagia, irritability, muffl ed cry

pres-or speech, tpres-orticollis, and stertpres-or Drooling and stridor may be present in severe cases The ret-ropharyngeal space consists of bilateral spaces separated by a midline raphe which is clinically important because infection in this space usu-ally causes unilateral pharyngeal bulging Occa-sionally, swelling from a retropharyngeal space infection may displace the tonsil in an anterior direction that mimics peritonsillar infection CT can usually determine the correct space of the infection

Infections in the retropharyngeal space can be severe and can spread from the base of skull to the mediastinum since the fascial planes are poten-tially contiguous (Figure 4) Retropharyngeal

Table 1 Studies in Which Children Had Computed Tomography Scans Showing Abscesses and Had Incision and

Drainage

Lazar and colleagues 6

Elden and colleagues 8

Vural and colleagues 9

Daya and colleagues 10

Figure 4 Computed tomography scan showing a rim

enhancing mediastinal abscess with a lucent center

(center) This abscess resulted from an inferior extension

of a retropharyngeal abscess.

CHAPTER 65 / Deep Head and Neck Space Infection 785

space infections occur between the prevertebral

and buccopharyngeal fascial layers Although

the origin of retropharyngeal space infections is

usually the nose, paranasal sinuses, or pharynx;

foreign body ingestion with pharyngeal trauma

can also lead to infection in this space, and some

authors recommend routine esophagoscopy to

rule out a foreign body.2

Retropharyngeal cellulitis is, of course,

treated with intravenous antimicrobial agents

Retropharyngeal abscesses are usually treated

with transoral incision and drainage plus

intra-venous antimicrobials The abscess may fi rst be

located with a needle aspiration

Prevertebral Space Infection

Prevertebral space infections usually arise from

staphylococcal or tuberculous infections of the

vertebral bodies These infections occur between

the vertebral bodies and the prevertebral fascia

In contrast to retropharyngeal space infections

which are unilateral because of the attachment

of the retropharyngeal midline raphe,

preverte-bral space infections cause a bulge in the midline

While retropharyngeal space abscesses are

usu-ally drained by transoral incision and drainage,

prevertebral abscesses are drained externally A

prevertebral space abscess requires long-term

drainage

Parapharyngeal Space Infection

The parapharyngeal (lateral pharyngeal) space

is shaped like an inverted pyramid and extends

from the lateral part of the base of the skull to

the hyoid bone It is divided into prestyloid and

poststyloid compartments The styloid process

and the attached fascia of the tensor veli palatini

divide the parapharyngeal space into a prestyloid

compartment that contains the internal maxillary

artery, the maxillary nerve, and the tail of the

parotid gland; and a poststyloid compartment that

contains the carotid artery, internal jugular vein,

cervical sympathetic chain, and cranial nerves

IX, X, XI, and XII Parapharyngeal space

infec-tions usually present with pain, fever, stiff neck,

and occasionally pain on opening the mouth

which is from involvement of the internal

ptery-goid muscle Imaging studies are useful to

dif-ferentiate abscess versus cellulitis Similar to the

other deep neck space infections, parapharyngeal

space cellulitis may be treated with intravenous

antimicrobials Abscesses in this space are

usu-ally drained by the external surgical approach

described below

Submandibular Space Infection

The submandibular space is divided into

supr-amylohyoid and infrsupr-amylohyoid portions by the

mylohyoid muscle The supramylohyoid portion

contains the sublingual glands and the

subman-dibular gland ducts The inframylohyoid portion

contains the submandibular glands and the

asso-ciated submandibular lymph nodes These two

portions of the submandibular space are in

con-tinuity at the posterior aspect of the mylohyoid

muscle As the duct of the submandibular gland passes posterior to the mylohyoid muscle, it also connects the supramylohyoid and inframylohyoid portions of the submandibular space The capsule surrounding the submandibular gland creates the space of the submandibular gland, which is also a potential site of abscesses Bounded by the ante-rior bellies of the digastric muscles, the submen-tal space contains lymph nodes and is a potential space for infection

Visceral Space Infection

Containing the thyroid gland, trachea, and agus, the visceral space can be infected and result

esoph-in quite serious laryngeal edema and airway obstruction The retrovisceral compartment of the visceral space is in continuity with the retropha-ryngeal space Early aggressive therapy is indi-cated to avoid airway obstruction

OPEN SURGICAL APPROACH TO DEEP NECK SPACE INFECTIONS

The indications for the open external neck approach to deep neck space infections include larger abscess (>1 cm), multilocular abscesses, failure of needle aspiration, complications, no improvement following 24 to 72 hours of intra-venous antimicrobials, and possibly when an unusual or resistant microorganism is suspected

This approach is useful for drainage of infections

in the parapharyngeal, submandibular, visceral, retropharyngeal, and prevertebral spaces and the carotid sheath

An incision is made approximately two fi gerbreadths below the lower border of the mandi-ble The lower border of the submandibular gland

n-is identifi ed and retracted superiorly If the tion is in the space of the submandibular gland, the fascial capsule of the gland is incised inferi-orly and the fascial capsule is dissected superiorly and gently retracted superiorly along with the marginal mandibular branch of the facial nerve

infec-Care should be taken to preserve this nerve and

to avoid a crush injury to the nerve from using a retractor against the mandible

Once the submandibular area has been addressed, the dissection continues deeply to identify the carotid sheath Once the carotid sheath has been identifi ed, if an abscess is pres-ent in the sheath it should be opened and drained

An abscess in the jugular vein may be drained by this approach, and the vein may also be ligated superior and inferior to the abscess The carotid sheath is an excellent landmark and pathway for further dissection to other deep neck spaces such

as the parapharyngeal, retropharyngeal, and ceral spaces Blunt fi nger dissection is an excel-lent and safe method to drain these spaces Once the abscess cavity or cavities have been entered, blunt fi nger dissection is also used to break up loculations and to make separate abscess cavi-ties into contiguous cavities when feasible Iodo-form gauze packing is placed into the deep aspect

vis-of the wound and brought out through the skin

incision The skin incision is only partially closed

to allow drainage and removal of the packing

The packing is slowly advanced out of the wound

in daily increments over 3 to 4 days

AIRWAY MANAGEMENT FOR DEEP NECK SPACE INFECTIONS IN CHILDREN

If deep neck space infection results in partial airway compromise in a child, early establish-ment of an artifi cial airway is strongly advised before the airway obstruction results in an acute emergency Elective establishment of an airway with a bronchoscope, endotracheal tube, naso-pharyngeal airway, or tracheostomy is strongly advised prior to the need for emergent interven-tion which has a higher risk of complications The artifi cial airway should be established in the operating room where equipment, good lighting, suction, and the most experienced airway per-sonnel are available

In small children, surgical manipulation and drainage of an abscess may result in edema and airway compromise In such children, planning to leave the endotracheal tube in place until edema resolves following drainage of the deep neck space abscess should be considered A plan to leave the endotracheal tube in place following drainage of a deep neck space abscess should be discussed with the parents prior to the operation

to avoid parental anxiety

Pain on opening the mouth occurs as the infection and infl ammation spread to the internal pterygoid muscle in the parapharyngeal space Laryngeal edema also occurs as the infection pro-gresses Thus the combination of edema of the

fl oor of the mouth, elevation of the tongue, pain on opening the mouth, and laryngeal edema contrib-ute to signifi cant airway obstruction (Figure 5) All but the occasional, earliest, mildest cases of Ludwig angina should have an artifi cial airway established rapidly before the child progresses

to complete airway obstruction A rare, early, mild case, with minimal edema can be treated expectantly in the intensive care unit, without an artifi cial airway, with intravenous antimicrobials alone

Although an abscess may not be present, wig angina is the exceptional deep head and neck space infection in which incision and drainage is recommended even in the absence of an abscess

Lud-After the airway has been established by tracheal intubation or tracheostomy, a horizontal

endo-786 PART IV / Pediatric Otorhinolaryngology

incision is made in the submental area and the

fascial layers and muscles that are encountered

are separated in the midline Lateral dissection

is also undertaken between the muscle layers to

drain any abscesses that may or may not be

pres-ent The wound is packed with iodoform gauze

which is advanced out over several days The

artifi cial airway is removed when the edema and

infection have resolved

OTHER HEAD AND NECK SPACE

INFECTIONS

Masticator Space Infection

The masticator space is a potential space created

by the splitting of the superfi cial layer of the

deep cervical fascia around the masseter, internal

pterygoid, and temporalis muscles This space

contains the ramus of the mandible and the

tem-poralis muscle The superior portion of the space

is known as the temporalis portion of the

mastica-tor space Abscesses may occur medial or lateral

to the temporal muscle Drainage of the lateral

portion is accomplished by hairline incisions

that extend through the temporalis fascia When

abscess occurs deep to the temporalis muscle in

the infratemporal fossa, the incision must also

extend through the temporalis muscle

When infection occurs in the inferior portion

of the masticator space, it may occur in a medial

or lateral position Infection in the lateral

por-tion will involve the masseter muscle, and

inci-sion and drainage will require preservation of the

facial nerve and its branches prior to detaching the

fascia from the mandible Infection in the medial

compartment will involve the internal pterygoid

muscle Infections in the medial portion of the

masticator space may be drained via intraoral

incision Infections in the masticator space often

arise from extension of dental infection

Parotid Space Infections

The parotid space is created by the splitting of the

superfi cial layer of the deep cervical fascia around

the parotid gland Infections in this space usually

arise from sialoadenitis Even when an abscess is

present, fl uctuance is usually not palpated, since

the fascial capsule is so dense and thick Imaging studies such as computed tomography are needed

to demonstrate an abscess

Superfi cial abscesses in the parotid space may

be drained by small superfi cial skin incisions in the direction of the facial nerve branches with gentle deeper blunt dissection Deep abscesses in the parotid space may only be drained after facial nerve identifi cation and preservation

Mandibular Space Infection

The superfi cial layer of deep cervical fascia splits to surround the mandible and thus forms the mandibular space Infection in this space usu-ally arises from dental infection Intraoral pain and swelling are noted, and the abscess may be drained by intraoral incision

Buccal Space Infection

Buccal space infection usually arises from dental infection Infection in this space can also arise

from hematogenous spread of Haemophilus infl enzae, but this is now rare in the immunization

u-era Cheek swelling and pain on opening the mouth are present The abscess may be drained via skin incisions in the direction of the facial nerve branches with gentle deep blunt dissection

Buccal space abscesses may also be drained via intraoral incision

Canine Space Infection

Canine space infections are a result of root abscesses of the upper canine teeth Toothache commonly precedes the facial swelling that occurs lateral to the nares The abscess may drain spon-taneously near the medial canthus It is important not to mistake canine space infection for dacryo-cystitis This abscess may be drained by incision

in the labial sulcus with superior elevation of the facial soft tissues The canine root abscess must also be addressed by the dentist

infec-is no improvement after 48 to 72 hours, repeat imaging studies and open surgical therapy should

be considered In seriously ill children without abscess who do not respond rapidly to standard antimicrobial therapy, the presence of resistant microorganisms such as methacillin resistant

Staphylococcus aureus should be considered and

vancomycin should be added to the therapy

Seriously ill children with large and locular abscesses or those with complications or Ludwig angina should be treated with aggres-sive incision and drainage Needle aspiration may be useful for drainage of small unilocular

multi-abscesses.22,23 Ultrasound or CT are useful to locate the abscess and guide needle aspiration

Some authors have recommended treatment

of patients with small (<1 cm) uncomplicated abscesses with intravenous antimicrobials alone with good success.24,25 However, this approach should not be used if the abscess lies in a criti-cal location such as immediately adjacent to the great vessels In such patients the abscess may erode into the great vessels with catastrophic consequences; and, therefore, aggressive incision and drainage is recommended

COMPLICATIONS

Complications associated with deep neck space infections are an indication for incision and drain-age The complications are listed in Table 2 The complication of internal jugular vein thrombosis deserves special discussion Patients with deep head and neck space infections that spike fevers repeatedly in the so called “picket fence” pattern may have internal jugular vein thrombosis which

is releasing septic emboli CT angiography and magnetic resonance angiography are excellent diagnostic studies for internal jugular vein throm-bosis Traditional angiography is also useful but

is associated with increased risk of complications

Treatment of internal jugular vein thrombosis includes aggressive incision and drainage of the abscess In addition, if the septic emboli continue, the internal jugular vein may be ligated or excised

Postoperative anticoagulation may help decrease the chances of propagation of the emboli

CONCLUSIONS

Although deep head and neck space infections continue to be serious, with appropriate use of diagnostic tests, antimicrobial agents, surgical drainage, or needle aspiration, complications can be avoided and favorable outcomes can be achieved

REFERENCES

1 Ungkanont K, Yellon R, Weissman J, et al Head and neck space infections in infants and children Otolaryngol Head Neck Surg 1995;112:375–82.

2 Sethi DS, Stanley RE Deep neck abscesses—changing trends J Laryngol Otol 1994;108:138–43.

3 Tan PT, Chang LY, Huang YC, et al Deep neck infections in children J Microbiol Immunol Infect 2001;34:287–92.

4 Knudsen TD, Simko EJ Eikenella corrodens: An unexpected pathogen causing a persistent peritonsillar abscess Ear Nose Throat J 1995;74:114–7.

Table 2 Complications of Deep Head and Neck Space Infections

Airway obstruction Septicemia Neuropathy Carotid artery rupture Jugular vein thrombosis Mediastinitis

Rupture into pharynx

Figure 5 Ludwig angina Photograph of a girl with rapidly

progressive edema and airway obstruction from bilateral

cellulitis of the submandibular spaces, woody induration

of the fl oor of the mouth, elevation of the tongue, and

laryngeal edema.

CHAPTER 65 / Deep Head and Neck Space Infection 787

5 Zgheib A, el Allaf D, Demonty J, Rorive G Intrathoracic

infections with bacteraemia due to Eikenella corrodens as a

complication of peritonsillar abscesses: Report of a case and

review of the literature Acta Clin Belg 1992;47:124–8.

6 Lazor JB, Cunningham MJ, Eavey RD, et al Comparison

of computed tomography and surgical fi ndings in deep neck

infections Otolaryngol Head Neck Surg 1994;111:746–50.

7 Choi SS, Vezina LG, Grundfast KM Relative incidence and

alternative approaches for surgical drainage of different types

of deep neck abscesses in children Arch Otolaryngol Head

Neck Surg 1997;123:1271–5.

8 Elden LM, Grundfast KM, Vezina LG Accuracy and

useful-ness of radiographic assessment of cervical neck infections

in children J Otolaryngol 2001;30:82–9.

9 Vural C, Gungor A, Comerci S Accuracy of computerized

tomography in deep neck infections in the pediatric

popula-tion Am J Otolaryngol 2003;24:143–8.

10 Daya H, Lo S, Papsin BC, et al Retropharyngeal and

para-phyaryngeal infections in children: The Toronto experience

Int J Pediatr Otorhinolaryngol 2005;69:81–6.

11 Beeden AG, Evans JNG Quinsy tonsillectomy—a further report J Laryngol Otol 1970;84:443–8.

12 McCurdy JA Pertonsillar abscess: A comparison of ment by immediate tonsillectomy and interval tonsillectomy

19 Dunne AA, Granger O, Folz BJ, et al Peritonsillar abscess—

critical analysis of abscess tonsillectomy Clin Otolaryngol Allied Sci 2003;28:420–4.

20 Herzon FS Permucosal needle drainage of peritonsillar abscesses Arch Otolaryngol 1984;110:104–5.

21 Schechter GL, Sly DE, Roper AL, Jackson RT Changing face of treatment of peritonsillar abscess Laryngoscope 1982;92:657–9.

22 Brodsky L, Belles W, Brody A, et al Needle tion of neck abscesses in children Clin Pediatr (Phila) 1992;31:71–6.

23 Herzon FS Management of nonperitonsillar abscesses of the head and neck with needle aspiration Laryngoscope 1985;95:780–1.

24 Broughton RA Nonsurgical management of deep neck tions in children Pediatr Infect Dis J 1992;11:14–8.

25 McClay JE, Murray AD, Booth T Intravenous otic therapy for deep neck abscesses defi ned by com- puted tomography Arch Otolaryngol Head Neck Surg 2003;129:1207–12.

antibi-Pediatric sleep-disordered breathing (SDB) is

viewed as a continuum of severity from

par-tial obstruction of the upper airway producing

snoring, to increased upper airway resistance to

continuous episodes of complete upper airway

obstruction or obstructive sleep apnea (OSA)

Although the prevalence of primary snoring in

children is 12%, the prevalence of OSA is 1 to

3% SDB is an important cause of morbidity in

children and may lead to growth failure,

neuro-cognitive and behavioral abnormalities, cor

pul-monale, and rarely death Early recognition and

treatment are important to prevent or treat these

disorders

HISTORICAL PERSPECTIVE

The earliest description of pediatric OSA is found

in a novel by Charles Dickens, The Posthumous

Papers of the Pickwick Club, which was published

in 1837 Dickens described an obese, red-faced,

hypersomnolent boy named Joe In the medical

literature, William Osler gave an extremely

accu-rate description of pediatric OSA in his textbook

in 1892 “At night the child’s sleep is greatly

dis-turbed; the respirations are loud and snorting, and

there are sometimes prolonged pauses, followed

by deep, noisy inspirations.” He also coined the

term “pickwickian” to describe morbidly obese,

hypersomnolent patients In 1956, Spector and

Bautista associated pediatric respiratory

dis-tress with tonsillitis and adenoiditis In 1965,

both Noonan and Menashe described reversible

cor pulmonale in children with adenotonsillar

hypertrophy Guilleminault and colleagues fi rst

described the clinical features of pediatric OSA

in 1976.1 Since then, additional case series and

cohort studies have drastically increased our

knowledge regarding the potential morbidities of

SDB and potential therapies, although much is

still unknown

DEFINITIONS

Classically childhood OSA has been defi ned

as partial or complete upper airway

obstruc-tion during sleep, usually associated with sleep

disruption, hypoxemia, hypercapnia, or daytime

symptoms (Figure 1).2 The diagnosis of OSA has

been based on threshold criteria on the overnight

polysomnogram (PSG) such as apnea index or

degree of oxygen desaturation Children who

snored but did not meet the threshold criteria for OSA were considered to be primary snorers (see Figure 1B), a condition which was believed

to be clinically insignifi cant In recent years, upper airway resistance syndrome (UARS) has identifi ed children with elevated upper airway resistance characterized by snoring, labored breathing, and paradoxical breathing without classic apnea or hypopnea (see Figure 1C)

These children exhibit similar clinical features

to children with classic OSA and improve after treatment

ETIOLOGY AND PATHOGENESIS

Pediatric OSA is caused by fi xed and dynamic narrowing of the airway which may occur at several sites Most commonly, enlarged tonsils and adenoid are the source of nasopharyngeal and oropharyngeal narrowing The tissues of Waldeyer ring (tonsils, adenoid, and lingual tonsil) progressively enlarge between ages 2 and 8 years and are largest in relation to the airway between 3 and 6 years of age Craniofa-cial abnormalities such as micrognathia or max-illary hypoplasia can narrow the upper airway

Lower airway abnormalities such as malacia can also impact airway patency Rapid air movement through a narrowed airway from any of these conditions induces further air-way collapse and obstruction The pharyngeal muscle hypotonia and muscle incoordination

laryngo-found in children with neuromuscular conditions and cerebral palsy produce dynamic airway narrowing

Given the multiple predisposing factors for pediatric SDB, no single factor accounts for all cases (Figure 2) Large tonsils and adenoid alone

do not cause SDB Numerous studies have been unable to fi nd a relationship between tonsil and adenoid size and the development of OSA Chil-dren with OSA do not exhibit obstruction when awake underscoring sleep-related dynamic air-way collapse Also, there have been reports of successful treatment by adenotonsillectomy in childhood with recurrence of SDB in the teenage years The current view is that children with OSA have an underlying abnormality of upper airway motor control or tone which when combined with enlarged tonsils and adenoid results in dynamic airway obstruction during sleep

The mechanisms underlying the development

of the neurocognitive and behavioral defi cits found in pediatric SDB are unknown Proposed mechanisms include sleep disruption, sleep frag-mentation, intermittent hypoxia, alterations in brain neurochemistry, brain infl ammation, hor-monal changes, changes in cerebral bloodfl ow,

or altered cerebral perfusion pressure Additional research is critically important in this area Other consequences of pediatric SDB, including pul-monary hypertension (cor pulmonale), hyperten-sion, and growth impairment, are likely caused

in part by the effects of intermittent hypoxia during sleep Hypoxemia or sleep fragmentation

Sleep Apnea in Children

B

Increased UAR sufficient to cause symptoms

Increased UAR sufficient to elevate PaCO2 or lower SpO2

resistance syndrome (UARS)

Obstructive hypoventilation syndrome

Obstructive sleep apnea (OSA)

E

Intermittent complete obstruction

Increasing Upper Airway Resistance (UAR)

790 PART IV / Pediatric Otorhinolaryngology

may affect brain neurochemistry and growth

hor-mone secretion Increased work of breathing with

fewer calories available for growth may lead to

failure to thrive Large swings in intrathoracic

pressure may affect cardiac afterload directly

The etiology of enuresis is unclear but may be

secondary to increased urine production due to

OSA, abnormal secretion of antidiuretic hormone

(ADH), or merely refl ect increased awakenings

and arousals

There is mounting evidence that there is a

familial predisposition to the development of

OSA as genetic-epidemiologic surveys of families

of index patients with OSA have demonstrated

a higher prevalence of SDB in family members

as compared to the general population.3 Genes

associated with obesity, craniofacial structure,

and muscle development of the upper airway soft

tissues are likely involved in the development

of OSA, but further work is needed to identify

specifi c loci

EPIDEMIOLOGY

The prevalence of snoring and pediatric OSA

have been estimated from community-based

cross sectional surveys of parental reports of

snoring and diffi culty breathing during sleep

The prevalence of snoring ranged from 2.4 to

12% while the prevalence of SDB ranged from

0.69 to 4% The peak incidence of pediatric OSA

is between 2 and 6 years of age when the tonsils

and adenoid are largest in relation to the size of

the underlying airway A second peak occurs

during adolescence with the development of the

adult body habitus and craniofacial structure

Most studies do not report gender differences

African American children have been reported

to be at increased risk (3.5 times) for developing

OSA and to be at increased risk for the

morbid-ity associated with OSA.3 Studies have reported

confl icting results regarding the prevalence of

allergic rhinitis, asthma, and exposure to passive

cigarette smoking in children with SDB

CLINICAL FEATURES Nighttime Symptoms

Snoring is the most common symptom of SDB, and OSA is extremely unusual in children who do not snore (Table 1) Other nighttime symptoms include apneic pauses, snorting, gasping, restless sleep, frequent arousals, frequent awakenings, sleeping with the neck hyperextended, unusual sleeping positions, for example, sitting, propped

up on pillows, fetal position, diaphoresis, sis, and other parasomnias A resuscitative snort often follows the apneic episodes Occasionally stridor is found Children may exhibit paradoxi-cal inward rib cage motion while cyanosis is rarely observed In children, OSA occurs mainly

enure-in rapid eye movement (REM) sleep, therefore symptoms may be absent for a signifi cant portion

of the night

Daytime Symptoms

Hypertrophy of the tissues of Waldeyer ring may lead to daytime obstructive symptoms including mouthbreathing, hyponasality, chronic rhinor-rhea, nasal obstruction, and dysphagia (Table 1)

A history of any of these symptoms should lead to an investigation of nighttime symptoms including snoring and possible apnea During an acute upper respiratory infection, there may be enlargement of the lymphoid tissues of Waldeyer ring resulting in snoring and nighttime breath-ing diffi culties These symptoms may be tem-porary and resolve once the infection subsides but may signal the onset of chronic upper airway obstruction

Failure to thrive has been reported to occur

in approximately 10% of children and 42 to 56%

of infants with OSA There have been several

reports documenting improvement in growth for children with failure to thrive and OSA after ade-notonsillectomy.4

Pulmonary hypertension is a rare tion of SDB Goldstein and colleagues, in two prospective studies evaluating the clinical diag-nosis of SDB performed echocardiograms on all study participants.5 Pulmonary hypertension was found in 0/30 (0%) and 1/56 (2%) of patients and resolved in the one patient after adenoton-sillectomy Miman and colleagues identifi ed 17 children with obstructive symptoms and adeno-tonsillar hypertrophy who had mild pulmonary hypertension by echocardiography.6 The pulmo-nary hypertension resolved in all patients after surgery In the studies by Goldstein and col-leagues, systemic hypertension was also found

complica-in 5/30 (16.7%) and 8/59 (20%) of patients.5 It resolved in all patients after adenotonsillectomy

While daytime sleepiness is extremely mon in adults with OSA, it is an uncommon

com-fi nding in children Behavioral and tive diffi culties have been found in 8.5 to 63%

neurocogni-of children with SDB Children with primary snoring but otherwise normal sleep study indi-ces have also been shown to have lower scores

on measures of behavior and cognition using a battery of neurobehavioral tests as compared to control children, although the mean scores for both groups were still in the normal range.7 Stud-ies using standardized behavioral and neurocog-nitive assessments have documented signifi cant improvements in test scores after adenotonsillec-tomy in children with SDB, suggesting that neu-rocognitive defi cits are potentially reversible

Poor academic performance has also been found in several studies of children with SDB

Only one study has evaluated improvement in academic performance after adenotonsillectomy

Gozal evaluated 297 fi rst grade children in the lowest tenth percentile of their class by overnight pulse oximetry and transcutaneous CO2 measure-ment.8 Fifty-four children demonstrated sleep-associated gas exchange abnormalities and 24

of these children underwent adenotonsillectomy

The mean grades of the children who underwent surgery increased signifi cantly during the fol-lowing academic year as compared to the chil-dren whose parents refused surgery There was

no academic improvement in the children with primary snoring and the children without SDB

These fi nding also suggest that the tive diffi culties found in children with SDB are reversible with treatment To further evaluate the long-term impact of SDB in early childhood, Gozal and Pope mailed questionnaires to the par-ents of seventh and eighth graders whose school performance was in the top 25% of the class

neurocogni-or the bottom 25% of the class, and who were matched for age, gender, race, school, and street

of residence.9 Snoring in early childhood was signifi cantly more common in the low perfor-mance group than the high performance group, but there was no signifi cant difference in current snoring Signifi cantly, more low performance children had a history of adenotonsillectomy

Figure 2 Pathophysiology of childhood sleep-disordered

breathing (SDB) (Adapted from reference 2.)

Upper Airway Narrowing

Upper Airway Tone

Arousal responses Neural drive Upper airway reflexes

Table 1 Clinical Features of Pediatric Disordered Breathing

Sleep-Nighttime symptoms Snoring

Apneic pauses Gasping Restless sleep Frequent arousals and awakenings Neck extension

Unusual sleeping positions Diaphoresis

Paradoxical chest wall motion Enuresis

Parasomnias Daytime symptoms Mouthbreathing Hyponasality Chronic rhinorrhea Nasal obstruction Dysphagia Behavior and neurocognitive diffi culties Poor school performance

Daytime sleepiness General

Poor growth or failure to thrive Pulmonary hypertension (cor pulmonale) Systemic hypertension

CHAPTER 66 / Sleep Apnea in Children 791

than high performance children These fi ndings

suggest that the neurocognitive impairments of

pediatric SDB may not be fully reversible

espe-cially if they occur during a critical period of

brain development

CONDITIONS ASSOCIATED WITH

PEDIATRIC SLEEP APNEA

A summary of conditions predisposing children

to sleep apnea is provided in Table 2.10

Obesity

Although obesity is a risk factor for pediatric

SDB, most children with SDB are not obese

However, the prevalence of SDB in obese

chil-dren is 25 to 40% Obesity predisposes chilchil-dren

to SDB by decreasing the cross-sectional area of

the upper airway by the deposition of adipose

tissue adjacent to the pharynx as well as

compres-sion from subcutaneous fat deposits in the neck

Individual symptoms and PSG abnormalities do

not correlate with the degree of obesity

Soul-tan and colleagues found that 10 of 17 children

who were obese or morbidly obese with OSA

had substantial weight gain after

adenotonsillec-tomy.11 Therefore treatment of the SDB will not

help with weight reduction in obese children and

might exacerbate the obesity Diet, exercise, and

behavior therapy are needed in addition to

surgi-cal therapy

Down Syndrome

The anatomic and physiologic factors that

pre-dispose children with Down syndrome to OSA

include midfacial and maxillary hypoplasia,

mac-roglossia, a narrow nasopharynx, a shortened

palate, generalized hypotonia, and a tendency to

obesity Shott and colleagues found the incidence

of OSA to be 57% in a 5-year longitudinal study

of 56 children with Down syndrome.12 Of the dren with abnormal sleep studies, 77% of the par-ents reported no sleep problems in their children

chil-Since many of the manifestations of SDB ing daytime sleepiness, behavioral problems, developmental delay, and pulmonary hyperten-sion are also common in children with Down syn-drome, there is often a delay in diagnosis

includ-Although adenotonsillectomy is usually the

fi rst-line treatment of SDB in children with Down syndrome, persistent signifi cant PSG abnormali-ties have been reported in up to 60% of children

Additional therapies may include nasal ous positive airway pressure (CPAP), uvulo-palatopharyngoplasty (UPPP), tongue reduction, maxillomandibuloadvancement, or tracheostomy

continu-The effi cacy of these surgical procedures in this patient population is unknown

OSA has been found in children with Pierre Robin sequence, Treacher Collins syndrome, Apert syndrome, Pfeiffer syndrome, Larsen syn-drome, Crouzon syndrome, Stickler syndrome, Goldenhar syndrome, velocardiofacial syndrome, and fragile X syndrome Infants with Pierre Robin sequence (micrognathia, glossoptosis, and cleft palate) may present with severe upper air-way obstruction, although appropriate manage-ment may prevent many of the complications

With growth of the mandible, the upper airway obstruction improves with age PSG is important for the diagnosis of SDB in children with cranio-facial abnormalities and to evaluate the children’s response to therapy Therapy includes adeno-tonsillectomy, UPPP, maxillary and mandibular advancement, mandibular distraction osteogen-esis, nasal CPAP, and tracheostomy

Achondroplasia

Achondroplasia is an autosomal dominant syndrome which is the most common form of dwarfi sm Midfacial hypoplasia, dysplasia of the basiocciput, foramen magnum stenosis with com-pression of the cervical spinal cord, and thoracic cage restriction predispose these children to OSA

Surgical management may involve lectomy, ventriculoperitoneal shunt, and foramen magnum decompression PSG and neurological and respiratory assessments are important in the workup of these patients

adenotonsil-Mucopolysaccharide Storage Diseases

The mucopolysaccharidoses are genetic disorders

in which enzyme defi ciencies lead to defective

degradation of lysosomal glycosaminoglycans with accumulation of mucopolysaccharides in the soft tissues of the body, including the respira-tory tract The type of mucopolysaccaridosis is determined by the particular enzyme defi ciency

Examples are Hurler and Scheie syndromes (iduronidase defi ciency), Hunter syndrome (idu-ronate sulfatase defi ciency), and Sly syndrome (β-glucuronidase deficiency) In addition to hypertrophy of the tonsils, adenoid, tongue, and oropharyngeal mucosa, deposits in the tracheo-bronchial tree often lead to chronic pulmonary disease These children often develop scoliosis, spinal problems, and hepatosplenomegaly OSA may be severe and a cause of death Treatment options include adenotonsillectomy, nasal CPAP, and tracheostomy These patients present com-plex airway management, and even tracheostomy may not insure control of the airway

α-L-Neuromuscular Disease and Cerebral Palsy

Children with neuromuscular disease are a erogeneous group and include children with neuropathies, congenital myopathies, muscular dystrophies, myotonias, and myasthenia gravis

het-These children have a loss of respiratory muscle function and a drop in central respiratory drive leading to both obstructive and central apnea The symptoms of SDB may be underestimated

as they may be diffi cult to distinguish from the underlying disease Treatment options include adenotonsillectomy, UPPP, tracheostomy, or CPAP Children with cerebral palsy have poor neuromuscular control, increased oropharyngeal secretions, seizures, and gastroesophageal refl ux disease (GERD) which may predispose them to SDB Adenotonsillar hypertrophy along with decreased pharyngeal tone contribute to upper airway collapse Treatment options include ade-notonsillectomy, UPPP, tongue hyoid advance-ment, mandibular advancement, tongue reduction, CPAP, and tracheostomy

of SDB, and SDB may be a predisposing tor for the occurrence of cerebrovascular acci-dents Adenotonsillectomy has been shown to

fac-be successful in the resolution of symptoms and improvement in alveolar hyperventilation Chil-dren with Prader–Willi syndrome have severe infantile hypotonia, feeding diffi culties, devel-opmental delay, craniofacial abnormalities, and obesity which all contribute to the development

of SDB Early treatment of SDB may delay the development of cor pulmonale, a common cause

of death in these children Iatrogenic causes of SDB are possible, most commonly from velopha-ryngeal fl ap surgery

Table 2 Predisposing Conditions

Craniofacial microsomia (hemifacial microsomia,

Goldenhar syndrome, 1st and 2nd branchial arch

792 PART IV / Pediatric Otorhinolaryngology

PHYSICAL EXAMINATION

The child’s general appearance should be assessed

with measurement of height, weight, and blood

pressure The craniofacial structure should be

assessed for midfacial hypoplasia, retrognathia,

micrognathia, and adenoid facies (open mouth,

long face, mandibular hypoplasia) The

pres-ence of mouthbreathing, stertor, and hyponasality

should be assessed The nose should be

exam-ined for the presence of structural abnormalities

The oropharyngeal examination should evaluate

tonsil size, tongue size, position of the palate,

dentition, and the presence of any structural

abnormalities The neck should be examined for

any neck masses The adenoid may be evaluated

by fl exible fi beroptic nasopharyngoscopy or by

the use of a small rigid telescope If laryngeal

abnormalities are suspected, fl exible fi beroptic

laryngoscopy may also be performed The chest

should be examined for the presence of a pectus

excavatum Neurologic function and

develop-ment should be assessed

DIAGNOSTIC STUDIES

Ancillary Studies

A lateral neck X-ray may be obtained to assess

adenoid size Cephalometric studies and upper

airway fl uoroscopy may be useful in children with

craniofacial abnormalities but are not routinely

used for otherwise healthy children An

electro-cardiogram, echoelectro-cardiogram, and chest

radio-graph may be obtained in children with severe

OSA or children with signs of congestive heart

failure to evaluate for pulmonary hypertension

A home audiotape recording of the child’s

breathing during sleep has a reported sensitivity

of 71 to 88% and a specifi city of 52 to 72% in

predicting a positive result on PSG in otherwise

healthy children.5,13 A home videotape recording

has been shown to have a sensitivity of 94% and

specifi city of 68% in predicting a positive PSG.14

Although not specifi c enough to distinguish

chil-dren with positive and negative sleep studies,

these tapes are convenient, inexpensive methods

to confi rm the parents’ description of the child’s

nighttime breathing diffi culties and are useful in

the clinical setting

Pulse oximetry is not useful as a screening tool

because of its low sensitivity but may prove useful

if positive in a snoring child in whom there is a

high index of suspicion for OSA Nap

polysom-nograms also exhibit poor sensitivity and are only

useful if they are positive The diffi culty with nap

studies is that children over 4 years of age rarely

nap, and REM sleep may be missed on a nap

study Ambulatory, unattended PSG performed in

the child’s home may have a role in the diagnosis

of SDB although end tidal CO2, EEG, and upper

airway resistance are usually not measured

Polysomnography

The PSG consists of electroencephalography and

electromyography for sleep staging, chest and

abdominal motion by strain gauges or tory inductive plethysmography, electrocardiog-raphy, pulse oximetry, nasal and oral airfl ow, and end-tidal or transcutaneous CO2 UARS is best detected by esophageal pressure monitoring, but this is not routine in most centers Ideally, pediat-ric sleep studies should be performed in a pediat-ric sleep laboratory with a technical staff trained

respira-to work with children

Obstructive apnea or the cessation of airfl ow with continued respiratory effort is defi ned as lasting at least 10 seconds in adults (Figure 3)

Since children have faster respiratory rates than adults, the duration of an obstructive apnea in

a child is two times the typical breath interval

An obstructive hypopnea is the partial tion of airfl ow with continued respiratory effort, although there is no uniform defi nition of hypop-nea in children among sleep laboratories A cen-tral apnea is the cessation of airfl ow due to lack

cessa-of respiratory effort (see Figure 3) Sleep study

fi ndings are commonly reported as the hypopnea index (AHI) or the number of apneas plus hypopneas per hour of sleep or the respira-tory disturbance index (RDI) or the number of all respiratory events including respiratory arousals per hour of sleep

apnea-The PSG criteria commonly used to diagnose OSA in a child are presented in Table 3 Marcus performed sleep studies on 50 normal children and found the average apnea index (AI) to be 0.1

± 0.5 events per hour, minimal O2 saturation was

96 ± 2% and average maximal desaturation was

4 ± 2% She concluded that apnea more frequent than one time per hour was abnormal Obstruc-tive hypoventilation can be identifi ed when the end tidal CO2 pressure is equal to or greater than 50 mm Hg for more than 8 to 10% of the total sleep time Awake esophageal pressure is usually between –10 and –5 cm of water, and UARS is diagnosed on the PSG when a repeti-tive breathing pattern with increasingly more negative esophageal pressure culminating in an arousal is found In the absence of esophageal pressure monitoring, some pediatric centers,

based on experience, will consider a study gestive of UARS if the thresholds for nocturnal awakenings (<1/hr), arousal index (<10/hr), or sleep effi ciency (>80%) are exceeded

sug-Limitations of Polysomnography Standards

for positive PSG in children have been based

on studies of their normative values However, few studies have documented the relationship between PSG abnormalities and daytime sleepi-ness, impaired neurocognitive function, behav-ioral abnormalities, or other adverse outcomes of pediatric SDB It is unclear whether children with mild PSG abnormalities, although outside of the normative range, require therapy PSG focuses heavily on breathing with minimal measures of sleep quality Normative data are limited to clas-sic OSA and are not available for UARS

It is controversial whether an otherwise healthy child needs a PSG prior to adenotonsillectomy

Reports have documented the inaccuracy of dicting which children with histories and physical examinations suggestive of OSA will have posi-tive PSG In seven trials, the accuracy of clini-cal evaluation of OSA was poor, ranging from

pre-30 to 85% On the basis of the published studies and because only 20 to 30% of snoring children have positive PSG, the American Thoracic Soci-ety Consensus Committee recommended PSG be obtained before adenotonsillectomy to differenti-ate primary snoring from OSA.15 Although the published studies suggest that clinical evaluation

is inaccurate in diagnosing OSA in children, most

of the studies used adult criteria for interpretation

of the sleep studies, which are now recognized to

be inappropriate for children In addition, none of the studies considered the diagnosis of UARS in the evaluations Weatherly and colleagues found that the accuracy of clinical assessment increased

as the PSG criteria for a positive study became less stringent.16 In a prospective, randomized, controlled trial of children with a positive clinical assessment for OSA but negative PSG, children who underwent adenotonsillectomy had signifi -cant improvement in clinical assessment scores compared to children who did not undergo sur-gery at 6-month follow-up.5 In addition, recent research has suggested that primary snoring in children may not be benign.7,9

PSG has been most useful to confi rm the nosis of OSA and document its severity in the fol-lowing situations: children who are younger than

diag-2 years; high-risk patients for which surgery is contraindicated; children with craniofacial abnor-malities, morbid obesity, or cerebral palsy; when

Figure 3 (A) Polysomnogram recording of a central

apnea (B) Polysomnogram recording of an obstructive apnea.

Table 3 Abnormal Values of Pediatric Polysomnography

Obstructive apnea index (AI) >1/h Apnea-hypopnea index (AHI) >5/h Peak end-tidal CO 2 >53 mm Hg End-tidal CO 2 >50 mm Hg for >10% of total sleep time Minimum oxyhemoglobin saturation (SpO 2 ) <92%

CHAPTER 66 / Sleep Apnea in Children 793

there is a discrepancy between the history and

physical examination; and children who remain

symptomatic after adenotonsillectomy PSG is

also a prerequisite to treatment with nasal CPAP

or bilevel positive airway pressure (BIPAP) in

high risk children or surgical failures

NATURAL HISTORY

Little is known about the natural history of

untreated SDB As children with OSA and

clini-cally signifi cant SDB are routinely treated, there

are no studies evaluating long-term effects or

possible resolution of SDB Two studies have

evaluated children with untreated primary

snor-ing and found that only 8 to 10% progressed to

mild OSA at 1- to 3-year follow-up.17 Although

infantile and childhood OSA may predispose

individuals to adult OSA because of anatomical

and familial factors, there is no current evidence

that adults with OSA had SDB during infancy

and childhood

TREATMENT

Medical

Topical nasal corticosteroids have been studied

to determine their ability to improve nasal airfl ow

and improve SDB Brouillette and colleagues

performed a randomized, triple-blind,

placebo-controlled trial of 6 weeks of nasal fl uticasone

propionate in 25 children with SDB.18 There

was signifi cant reduction in the

mixed/obstruc-tive apnea/hypopnea index in the study patients

from 10.7 ± 2.6 to 5.8 ± 2.2 as compared to the

placebo group, although there was no signifi cant

change in symptom score and tonsil and adenoid

size between groups Although the study

demon-strated a moderate reduction in the AI, an index

of 5.8 is still abnormal and the patients

contin-ued to have episodes of desaturation In addition,

patients with severe OSA, 4+ tonsils, and

cra-niofacial conditions and infants were excluded

The study also did not address the duration of

therapy, so it is unclear whether the topical nasal

corticosteroids must be continued for a continued

response

Al-Ghamdi and colleagues performed an

open-label pilot study of 5 days of oral

predni-sone on nine children with OSA.19 There was no

improvement in symptomatology, sleep study

indices, or tonsil and adenoid size There have

been two studies evaluating oral antibiotics

Scla-fani and colleagues performed a prospective,

ran-domized, double blinded, placebo-controlled trial

of 30 days of amoxicillin/clavulanate potassium

in 168 children with obstructive symptoms.20

Sleep studies were not performed Treatment

with the antibiotic signifi cantly reduced the need

for adenotonsillectomy at 1-month follow-up as

compared to placebo (37.5% vs 62.7%) By 24

months, most of the children in both groups had

undergone adenotonsillectomy (83.3% of the

study group versus 98.0% of the placebo group)

Don and colleagues performed a randomized,

double-blinded, placebo-controlled trial of

30 days of azithromycin in 22 children with OSA documented by PSG.21 There were no signifi cant differences in sleep study indices, tonsil size, or symptoms in the azithromycin group as compared

to the placebo group These preliminary studies suggest that the above therapies are not indicated for children with severe OSA but may have a role

in the treatment of milder SDB or for temporary relief of symptoms

Nasal CPAP or BIPAP is used in children with predisposing factors for OSA including craniofacial anomalies, neuromuscular weak-ness, or obesity in whom adenotonsillectomy is ineffective or not indicated and for children with idiopathic OSA after adenotonsillectomy Stud-ies have reported effi cacies of 86 to 100% in nor-malizing PSG indices with long-term compliance rates of 80% Supplemental oxygen has been used

as a temporary measure to improve oxygenation

in children with OSA, although end tidal CO2must be monitored as alveolar hypoventilation can occur It is not recommended as the sole treat-ment modality for OSA Weight loss is important

in obese children to improve SDB and to reduce the risk for additional comorbidities related to obesity

Children with a constricted maxillary arch and associated narrowing of the nasal airway may benefi t from rapid maxillary expansion An orthodontic appliance is fi xed to anchor teeth and rapidly expanded over 3 weeks followed by a stabilization period of 6 to 12 months Studies

in selected children demonstrate improvements

in SDB It should be considered in older children who have failed other treatments

Tonsillectomy and Adenoidectomy

The fi rst-line therapy for the treatment of OSA or signifi cant SDB in otherwise healthy children is adenotonsillectomy It may also be the fi rst line treatment in complex patients if the tonsils and adenoids are enlarged Review of the published literature evaluating the success of adenotonsil-lectomy in otherwise healthy children reveals prospective observational, uncontrolled studies, and restrospective case series Due to ethical con-cerns, there are no randomized, controlled trials comparing adenotonsillectomy to no treatment

Most studies report a success rate for resolution

of PSG abnormalities of 75 to 100% A analysis by Lipton and Gozal reported a success rate of 80%.22 Studies evaluating clinical reso-lution of obstructive symptoms after adenoton-sillectomy report higher cure rates in the range

meta-of 90 to 100%, highlighting the need for further evaluation of the validity of PSG abnormalities in predicting future morbidity

The postoperative pain associated with notonsillectomy as well as the small risk of post-operative hemorrhage has led the development of

ade-a number of different surgicade-al techniques noidectomy may be performed using curettes, electrocautery, or the microdebrider The clas-sic technique of tonsillectomy was the “cold-dissection” in which the tonsil was grasped, the

Ade-anterior tonsillar pillar incised, and the capsule dissected off the pharyngeal constrictors using blunt and sharp dissection Hemostasis was obtained by suture ligature or electrocautery Monopolar electrocautery has become the most popular technique of tonsil dissection in the past quarter century as it affords greater hemostasis during the dissection It may be associated with increased postoperative pain and longer healing times

Newer techniques include bipolar cautery, harmonic scalpel, plasma excision (coblation), powered intracapsular tonsillectomy (PIT), and radiofrequency volume reduction Bipolar cautery allows precise coagulation with less tis-sue injury and may be performed using a small bipolar bayonet forceps with the operating room microscope or bipolar electrosurgical scissors The harmonic scalpel uses ultrasonic vibration

to transfer mechanical energy suffi cient to break hydrogen bonds Its vibrating titanium blades cut

at a frequency of 55.5 kHz, generating minimal heat and tissue damage Coblation uses current that is conducted through normal saline fl uid or gel The radiofrequency energy excites the saline solution creating a fi eld of active protons that break molecular bonds between tissues There is potentially reduced thermal injury and postop-erative pain because of the lower temperatures produced Preliminary studies comparing the har-monic scalpel and coblation with the traditional techniques have not demonstrated a clear advan-tage in terms of postoperative pain and reduction

of postoperative hemorrhage rates, but additional studies are needed

PIT using the microdebrider allows removal

of the bulk of the tonsil with preservation of the tonsillar capsule to act as a “biologic dressing”

over the pharyngeal constrictor muscles Due to decreased thermal injury to the tonsillar fossa musculature, there is potentially reduced postop-erative pain and hemorrhage However, there is potential regrowth and infection of the remain-ing tonsil tissue Retrospective studies comparing PIT with monopolar electrocautery tonsillectomy have revealed signifi cantly less postoperative pain, use of analgesics, and a quicker return to normal diet in the PIT group The largest of the studies was able to show a signifi cant reduction

in delayed postoperative bleeding and sion for dehydration in patients who had PIT; these patients had a low rate of tonsil regrowth (0.46%, 95% CI 0.009 to 0.9%).23 Two recent prospective studies comparing PIT with mono-polar electrocautery tonsillectomy show more modest benefi ts, and there were no differences

readmis-in groups with respect to postoperative tions Although the technique appears promising, more data are needed regarding its effectiveness and potential for recurrence of SDB secondary to tonsil regrowth

complica-Radiofrequency tonsil reduction involves inserting a temperature-controlled radiofrequency probe directly into the tonsillar tissue The probe generates a current that creates a region of tissue destruction which contracts over time, reducing

794 PART IV / Pediatric Otorhinolaryngology

tonsil volume In adults, the procedure may be

performed in the offi ce under local anesthesia

Because of their inability to cooperate and the

need for concomitant adenoidectomy, children

still require a general anesthetic Preliminary

results are promising but larger studies are still

needed

Children with OSA are at risk for

postopera-tive respiratory complications Although the risk

of postoperative respiratory complications in the

general pediatric population ranges from 0 to

1.3%, rates of 16 to 27% have been reported in

children with OSA.24 Risk factors are age under

three, pulmonary hypertension or other cardiac

abnormalities, craniofacial syndromes, failure to

thrive, hypotonia, acute airway obstruction,

mor-bid obesity, and severe sleep study indices These

high-risk children require inpatient monitoring

of their cardiorespiratory status after

adenoton-sillectomy Narcotic analgesics should be used

judiciously These children may require oxygen

therapy, corticosteroids, a nasopharyngeal

air-way, CPAP or BIPAP, or endotracheal intubation

if respiratory compromise develops

Postopera-tive pulmonary edema is a rare complication that

may occur after the relief of chronic upper airway

obstruction Treatment includes oxygen therapy,

possible mechanical respiratory support with

positive end-expiratory pressure (PEEP),

restric-tion of intravenous fl uids, diuretics, and possibly

corticosteroids

After tonsillectomy, children experience

throat pain that lasts 1 to 2 weeks, referred otalgia

from the pharyngeal surgical site, and halitosis

Nausea and vomiting may develop from the

anes-thetic agents, the swallowing of bloody

secre-tions, or adverse reactions to narcotic analgesics

Some children after adenoidectomy will develop

neck pain especially with extension and neck

stiffness secondary to prevertebral infl ammation

If the neck pain persists longer than two weeks,

C1–C2 subluxation should be suspected A soft

diet is recommended for 10 to 14 days with a

gradual return to normal activities

Acetamino-phen should be used liberally AcetaminoAcetamino-phen

with codeine may also be used but with discretion

in high-risk patients Nonsteroidal anti-infl

am-matory agents are avoided due to the increased

risk of postoperative hemorrhage Postoperative

antibiotics are usually prescribed because of their

benefi cial effects on pain, fever, and halitosis

Perioperative corticosteroid administration has

been shown to reduce vomiting and pain in the

fi rst 24 hours

Dehydration is a complication of

adeno-tonsillectomy that may require readmission for

intravenous hydration and pain management

Rehydration should be performed with isotonic

solutions in appropriate volumes Hyponatremia

has been reported as a potential lethal

complica-tion after tonsillectomy caused by inappropriate

administration of hypotonic solutions in

chil-dren with intravascular depletion In the surgical

patient, free water is retained because there is an

increase in antidiuretic hormone (ADH)

secre-tion in response to decreased circulating blood

volume Administration of hypotonic solutions maintains these elevated ADH levels leading

to the retention of free water with a resultant decrease in serum sodium and serum osmolality

Postoperative hemorrhage is the most mon severe complication of tonsillectomy, occur-ring in 2 to 4% of patients Primary bleeding occurs within the fi rst 24 hours and is considered

com-to be related com-to surgical technique while delayed bleeding occurs within the fi rst 10 days (most commonly on the sixth or seventh day) and is attributed to the slough of eschar Bleeding may stop spontaneously, but children with signifi -cant bleeding should be admitted and observed

Attempts may be made to control bleeding in the emergency room, but many children require control in the operating room A clot in the ton-sillar fossa indicates recent bleeding and must

be removed to determine if the bleeding has stopped Repeated bleeding may indicate injury

to a large vessel with pseudoaneurysm tion Angio graphy and selective embolization may be required to diagnosis and treat this rare complication

forma-Preoperative coagulation studies are not formed routinely before adenotonsillectomy as they have limited predictive value and are not cost-effective However, children with a history

per-of abnormal bleeding or children with a family history of bleeding or coagulation disorders do warrant a preoperative workup Children with sickle cell disease are at increased risk for com-plications after adenotonsillectomy Protocols have been developed which include aggressive hydration and preoperative transfusions to reduce the percentage of hemoglobin S to less than 30 to 40% Children with type 1 von Willebrand dis-ease are successfully managed with preoperative administration of desmopressin acetate (DDAVP)

Children with sickle cell disease, hemophilia, and other coagulopathies should be managed in con-junction with a pediatric hematologist

Other Surgical Modalities

Surgical modalities other than tomy are considered for children who are not improved with it and children with other comor-bid conditions PSG is mandatory in this group

adenotonsillec-of children to confi rm the diagnosis and ment the severity of SDB The other surgical procedures for OSA are presented in Chapter

docu-86, “Sleep Medicine and Surgery.” Most ies on surgical modalities other than adenotonsil-lectomy have evaluated children with comorbid conditions Four studies have evaluated UPPP in neurologically impaired patients Success rates measured by clinical or PSG criteria ranged from

stud-80 to 87%.25 UPPP may be considered in children

or adolescents with continued palatal obstruction after adenotonsillectomy Concerns about mid-face growth have limited the use of septoplasty

in the preadolescent, but it may be considered

in older children with continued nasal tion Although temperature-controlled radiofre-quency reduction has been used for reduction of

obstruc-the inferior turbinates, soft palate, and base of tongue in adults, little has been published regard-ing its use in children

Mandibular distraction osteogenesis has been described in children with micrognathia and respiratory distress from Pierre Robin sequence, Treacher Collins syndrome, Nager syndrome, and hemifacial microsomia The procedure has been used successfully to prevent tracheostomy

in affected infants, treat OSA in older children without tracheostomy, and allow decannulation

In the largest of the published series, 7 of 8 (88%) infants avoided tracheostomy and 5 of 6 (83%) older micrognathic children were cured of OSA, but only 2 of 12 (17%) children with tracheos-tomies and complex congenital syndromes were successfully decannulated.26

Cohen and Burstein have published several case series describing their use of skeletal expan-sion combined with soft-tissue reduction in their children with craniofacial syndromes or cerebral palsy and refractory OSA.27 In addition to adeno-tonsillectomy and UPPP, soft-tissue procedures included septoplasty and turbinectomy, tongue reduction, and tongue hyoid suspension Skel-etal expansion procedures included mandibular advancement, costochondral grafts, mandibular distraction, temporomandibular joint arthro-plasty, and LeFort procedures Tracheostomy was avoided in 90% of their patients, whereas 80% of their patients with tracheostomies were successfully decannulated Supplemental oxygen therapy or CPAP was still required by 8% of the patients Mandibular osteotomy with genio-glossus advancement, hyoid myotomy with sus-pension, and maxillary-mandibular advancement may also be considered in otherwise healthy children who do not improve with adenotonsil-lectomy if the facial skeleton and dentition are mature, although there are few studies addressing these procedures in this group of children Tra-cheostomy is thought to be curative in children with refractory OSA and should be considered if the RDI is greater than 60 and oxygen desatura-tion is less than 70% if CPAP is not tolerated

CENTRAL APNEA

Central apnea is abnormal if it lasts 20 seconds or longer or is of any duration but associated with 4% oxygen desaturation or bradycardia Three

or more events per hour are considered mal Periodic breathing describes an alternat-ing pattern of respirations followed by a central respiratory pause Periodic breathing is com-monly found in healthy neonates but should be considered abnormal in infants and children if

abnor-it accounts for more than 5% of total sleep time

Diagnosis of central apnea and periodic ing may be diffi cult as these children may appear perfectly healthy when awake Premature infants may exhibit these breathing patterns in the neo-natal intensive care unit or may be admitted after

breath-an acute life-threatening event Older children may have daytime sleepiness, restless sleep, and

CHAPTER 66 / Sleep Apnea in Children 795

cyanosis during sleep but usually not snoring

A PSG is required for diagnosis

The differential diagnosis of central apnea

and periodic breathing is large, and the workup

should be tailored to the likely cause (Table 4).28

Apnea of prematurity occurs in 84% of infants

less than 1,000 g and 25% of infants less than

2,500 g and is commonly a pattern of mixed

central and obstructive apnea The most

com-mon cause is respiratory control immaturity, but

central nervous system abnormalities, bacterial

or viral infection, anemia, hypoglycemia,

electro-lyte imbalance, and sedating medications are also

causative The role of GERD is controversial

While chemical irritation of the larynx by a refl ux

episode may activate the laryngeal refl ex and

cause apnea, a clear causal relationship between

GERD and apnea of prematurity has not been

determined Treatment options include CPAP,

high-fl ow nasal cannula therapy, and

methylxan-thines such as theophylline and caffeine

Congenital central hypoventilation syndrome

(CCHS or Ondine curse) is an extremely rare

entity in which affected children demonstrate

severe hypoventilation particularly during sleep

because they lack the normal ventilatory responses

to hypercarbia and hypoxia These children

usu-ally present shortly after birth with cyanosis upon

8 Gozal D Sleep-disordered breathing and school performance

in children Pediatrics 1998;102:616–20.

9 Gozal D, Pope DW, Jr Snoring during early childhood and academic performance at ages 13 to 14 years Pediatrics 2001;107:1394–9.

10 Richardson MA Sleep apnea in children: History and physical exam In: Richardson MA, Friedman NR, editors

Clinician’s Guide to Pediatric Sleep Disorders New York:

Informa Healthcare USA, Inc.; 2007 p 65.

11 Soultan Z, Wadowski S, Rao M, Kravath RE Effect of ing obstructive sleep apnea by tonsillectomy and/or adenoid- ectomy on obesity in children Arch Pediatr Adolesc Med 1999;153:33–7.

12 Shott SR, Amin R, Chini B, et al Obstructive sleep apnea:

Should all children with Down syndrome be tested? Arch Otolaryngol Head Neck Surg 2006;132:432–6.

13 Lamm C, Mandeli J, Kattan M Evaluation of home audiotapes

as an abbreviated test for obstructive sleep apnea syndrome (OSAS) in children Pediatr Pulmonol 1999;27:267– 72.

14 Sivan Y, Komecki A, Schonfeld T Screening obstructive sleep apnoae syndrome by home videotape recording in chil- dren Eur Respir J 1996;9:2127–31.

15 American Thoracic Society Standards and indications for cardiopulmonary sleep studies in children Am J Respir Crit Care Med 1996;153:866–78.

16 Weatherly RA, Ruzicka DL, Marriott DJ, Chervin RD, somnography in children scheduled for adenotonsillectomy

Poly-Otolaryngol Head Neck Surg 2004;131:727–31.

17 Marcus CL, Hamer A, Loughlin GM Natural history of mary snoring in children Pediatr Pulmonol 1998;26:6–11.

18 Brouillette RT, Manoukian JJ, Ducharme FM, et al Effi cacy of fl uticasone nasal spray for pediatric obstructive sleep apnea J Pediatr 2001;138:838–44.

19 Al-Ghamdi SA, Manoukian JJ, Morielli A, et al Do systemic corticosteroids effectively treat obstructive sleep apnea sec- ondary to adenotonsillar hypertrophy? J Pediatr Laryngo- scope 1997;107:1382–7.

20 Sclafani AP, Ginsburg J, Shah MK, Dolitsky JN Treatment

of symptomatic chronic adenotonsillar hypertrophy with amoxicillin/clavulanate potassium: Short- and long-term results Pediatrics 1998;101:675–81.

21 Don DM, Goldstein NA, Crockett DM, Davidson Ward S

Antimicrobial therapy for children with adenotonsillar trophy and obstructive sleep apnea: A prospective random- ized trial comparing azithromycin vs placebo Otolaryngol Head Neck Surg 2005;133:562–8.

22 Lipton AJ, Gozal D Treatment of obstructive sleep apnea

in children: Do we really know how? Sleep Med Rev 2003;7:61–80.

23 Solares CA, Koempel JA, Hirose K, et al Safety and effi cacy

of powered intracapsular tonsillectomy in children: A center retrospective case series Int J Pediatr Otorhinolaryn- gol 2005;69:21–6.

24 McColley SA, April MM, Carroll JL, et al Respiratory compromise after adenotonsillectomy in children with obstructive sleep apnea Arch Otolaryngol Head Neck Surg 1992;118:940–3.

25 Kerschner JE, Lynch JB, Kleiner H, et al ryngoplasty with tonsillectomy and adenoidectomy as a treat- ment for obstructive sleep apnea in neurologically impaired children Int J Pediatr Otorhingolaryngol 2002;62:229–35.

26 Mandell DL, Yellon RF, Bradley JP, et al Mandibular traction for micrognathia and severe upper airway obstruc- tion Arch Otolaryngol Head Neck Surg 2004;130:344–8.

27 Cohen SR, Simms C, Burstein FD, Thomsen J Alternatives

to tracheostomy in infants and children with obstructive sleep apnea J Pediatr Surg 1999;34:182–7.

28 Lee RL Nonobstructive sleep patterns in children In: ardson MA, Friedman NR, editors Clinician’s Guide to Pediatric Sleep Disorders New York: Informa Healthcare USA, Inc.; 2007 p 35.

Rich-SUGGESTED READING

Carroll JL Obstructive sleep-disordered breathing in dren: New controversies, new directions Clin Chest Med 2003;24:261–82.

This article is a comprehensive review of pediatric SDB lighting new developments and controversies regarding def- initions, diagnostic criteria, pathophysiology and treatment.

Messner AH Evaluation of obstructive sleep apnea by nography prior to pediatric adenotonsillectomy Arch Oto- laryngol Head Neck Surg 1999;125:353–6.

This paper discusses the pros and cons of obtaining a PSG prior

to adenotonsillectomy in otherwise healthy children with suspected SDB.

falling asleep CCHS is a diagnosis of exclusion

as primary neuromuscular, cardiac, pulmonary, and metabolic diseases must be excluded Most children will require placement of a tracheos-tomy and mechanical ventilation for treatment

Diaphragm pacing via phrenic nerve stimulation

or BIPAP is another alternative Approximately

15 to 20% of these children will present with Hirschsprung disease, but other autonomic ner-vous system abnormalities are common

Disruption of the normal anatomical ships within the brainstem can result in respi-ratory control abnormalities This can occur in brainstem tumors or Chiari malformations In Type I Chiari malformation (CM-I), there is herniation of the cerebellar tonsils through the foramen magnum often with an associated syr-inx CM-I usually presents in older children and adults CM-I may be asymptomatic, but patients may present with occipital headaches, a wide variety of neurologic symptoms, and central apnea In Chiari malformation Type II (CM-II), there is caudal displacement of the cerebellar ver-mis and brainstem There is always an associated myelomeningocele and hydrocephalus is com-mon CM-II is usually diagnosed shortly after birth Infants may present with prolonged expira-tory apnea and cyanosis that can lead to brady-cardia and death Stridor may be indicative of vocal cord paralysis and can manifest as obstruc-tive apnea Children with suspected Chiari mal-formations require magnetic resonance imaging

relation-of the posterior fossa, brainstem, and spine and should be referred to a neurologist or neurosur-geon for management Patients with CM-II and hydrocephalus require immediate shunting fol-lowed by decompression surgery Asymptomatic patients with CM-I may be observed, but patients with apnea, syncope, vocal cord paralysis, and aspiration and those who fail medical manage-ment require decompression Success rates for CM-I approach 80 to 90%, but the outcomes for CM-II are not as good, with up to 15% dying by age three and one-third having continued central nervous system defi cits

REFERENCES

1 Guilleminault C, Eldridge FL, Simmons FB, Dement WC

Sleep apnea in eight children Pediatrics 1976;58:23–30.

2 Carroll JL Obstructive sleep-disordered breathing in dren: New controversies, new directions Clin Chest Med 2003;24:261–82.

3 Redline S, Tishler PV, Schluchter M, et al Risk factors for sleep-disordered breathing in children: Associations with obesity, race, and respiratory problems Am J Respir Crit Care Med 1999;159:1527–32.

4 Ahlqvist-Rastad J, Hultcrantz E, Melander H, Svanholm

H Body growth in relation to tonsillar enlargement and tonsillectomy Int J Pediatr Otorhinolaryngol 1992;

24:55–61.

5 Goldstein NA, Pugazhendhi V, Rao SM, et al Clinical assessment of pediatric obstructive sleep apnea Pediatrics 2004;114:33–43.

6 Miman MC, Kirazli T, Ozyurek R Doppler phy in adenotonsillar hypertrophy Int J Pediatr Otorhinolar- yngol 2000;54:21–6.

7 O’Brien LM, Mervis CB, Holbrook CR, et al ioral implications of habitual snoring in children Pediatrics 2004;114:44–9.

Neurobehav-Table 4 Differential Diagnosis of Central Apnea

Congenital

Apnea of prematurity

Mild alveolar hypoventilation

Congenital central hypoventilation syndrome

Late-onset central hypoventilation with

Cervical transverse myelitis

Brainstem or cervical spinal tumor

Metabolic disorders (acid maltase defi ciency,

hypophosphatemia, hypermagnesemia, Leigh

disease, pyruvate dehydrogenase defi ciency,

carnitine defi ciency

Adapted from reference 28.

The development of image-guidance and robotic

surgical systems has facilitated the expansion of

minimally invasive approaches to complex

sur-gical head and neck problems In addition, the

development of surgical simulators allows for

alternative methods to develop surgical skills This

chapter reviews the roles of these technologies in

otorhinolaryngology head and neck surgery

IMAGE-GUIDANCE SYSTEMS

Image-guidance systems were initially

devel-oped for neurotological and neurosurgical

pro-cedures using a stereotactic frame that required

fi xation of the patient’s head.1 They have been

subsequently adapted for use in endoscopic sinus

surgery These systems assist the surgeon with

intraoperative stereotactic anatomic localization

through the use of computerized tracking devices

The tracking devices can localize the position of

endoscopic instruments within the sinonasal

cav-ity and depict them on a real-time video display

of the preoperative computed tomography (CT)

scan using the digital data set of the imaging

study

At this time, there are four types of

technol-ogy that allow intraoperative image guidance:

electromechanical, electromagnetic, optical, and

sonic For practical purposes, electromagnetic and

optical systems are the most useful for

computer-guided endoscopic surgery (CGES) The sonic

system is not widely available in the United

States An example of the electromechanical

sys-tem was introduced by ISG Technologies

(Mis-sissauga, Ontario, Canada) and uses a mechanical

arm (“wand”) for anatomic localization Anon

and colleagues reviewed their experience with

this system in 70 patients No complications were

reported; and, anecdotally, the authors felt the

system was useful in revision surgery, massive

disease, frontal recess or sphenoid surgery, and

the presence of anatomic variants.2 However, this

system requires preoperative placement of fi

du-cial markers, re-registration with intraoperative

head movement, and a mechanical arm.3 While

these more complex systems are necessary for

use with neurotologic skull base surgery tions, the electromagnetic and optical systems are currently the most commonly used for paranasal sinus surgery

applica-There is only one electromagnetic system, represented by the InstaTrak (General Electric Medical Systems, Milwaukee, WI) This system relies on a radio frequency transmitter mounted

to a patient headset and an electromagnetic sensor incorporated into a handpiece The InstaTrak is a frameless, wandless system that uses preopera-tive CT images for triplanar real-time intraopera-tive localization of curved and straight surgical aspirators The headset contains seven fi ducial markers Disadvantages of this system include the need to wear a headpiece during the preop-erative CT scan and interference from metallic objects near the surgical fi eld Neumann and col-leagues reported their experience using the elec-tromagnetic InstaTrak system in 109 patients, 76

of whom had undergone previous surgery.4 The estimated accuracy was <3 mm in 106 (97.2%) patients and in no patients did unacceptable intra-operative drift occur Setup of the InstaTrak sys-tem, including headset placement, draping, cali-bration, and verifi cation took less than 5 minutes

in all cases Orbital fat exposure occurred in two patients and was the only reported intraoperative complication Two patients developed cerebro-spinal fl uid (CSF) leaks, but these were antici-pated given the underlying pathology (osteoma and meningioma) Postoperative complications included persistent synechiae in four patients and epistaxis in one patient These authors concluded that the technology was useful for all patients undergoing revision sinus surgery, patients with skull base defects or paranasal sinus neoplasms, and patients undergoing primary surgery with extensive disease

The optical-based image-guidance system lizes an infrared camera to monitor instrument and head position Light emitting diodes (LEDs) are mounted on the surgical instrument and the headset worn by the patient, which are tracked

uti-by an infrared camera The tracking data are cessed by an optical digitizer which displays the

pro-instrument location on reformatted and triplanar

CT images Several authors have evaluated the utility of this stereotactic system in neurotologic skull base surgery and in endoscopic sinus sur-gery.2,5,6 Metson and colleagues reviewed 754 consecutive patients undergoing CGES by 34 physicians using the LandmarX system (Xomed, Inc., Jacksonville, FL) This is a wandless, frame-less system that does not require fi ducial or head-set placement for the preoperative CT scan The mean accuracy of anatomical localization at the beginning of surgery was 1.69 ± 0.38 mm when

fi ve anatomical fi ducials were used in the tration process The use of the image-guidance system was estimated to increase operating room time by 15 to 30 minutes for the fi rst fi ve cases each surgeon performed With experience, surgeons required only 5 to 15 minutes setup time There were no intraoperative complications although there were three patients experienced epistaxis that occurred within one week after the opera-tion The epistaxis was not thought to be related

regis-to CGES The mean follow-up was 15 months A questionnaire was also completed by the surgeons who used the system The most common situation

in which CGES was utilized was after revision sinus surgery The major reported disadvantage was increased operating room time (71%), and the major advantage was an increased level of confi dence during surgery (85%) The overall use

of this system was rated either “easy” (31.8%) or

“very easy” (50%) by the surgeons In addition, most surgeons (92%) anticipated continued use

at the same or increased frequency The authors conclude that optical-based CGES can be suc-cessfully integrated into a busy operating room environment used by multiple sinus surgeons In addition, when properly used, it may extend the limits of safe and effective sinus surgery, espe-cially in patients with distorted landmarks.7

Computer-Guided Endoscopic Sinus Surgery:

Indications

Endoscopic sinus surgery is a viable option for the management of medically refractory sinona-sal infl ammatory disease, neoplasms, and skull

Robotic Surgery, Navigational Systems and Surgical

798 PART IV / Pediatric Otorhinolaryngology

base defects However, frequently, the anatomy

has been distorted by previous surgery or the

dis-ease process In addition, bleeding in severe

sino-nasal infl ammation or some neoplasms, bleeding

can obscure the surgeon’s visualization This can

make thorough removal of diseased tissue diffi cult

and potentially hazardous Given the close

prox-imity of vital structures including the intracranial

contents and orbit, even minimal intraoperative

disorientation can result in serious complications

In an attempt to improve the safety and effi cacy

of the endoscopic approach to sinonasal disease,

image-guidance systems have been developed

Several authors have reviewed their experience

with the different types of image-guidance

sys-tems; however, it is still unclear from the

cur-rent published literature if computer-guided

endoscopic sinus surgery (CGESS) accomplishes

these goals

The ideal image-guidance system allows for

correlation of the patient’s anatomy with the

CT image to 2 mm or less Additionally,

intra-operative head movement should not affect the

accuracy of the system Other favorable

character-istics include a frameless, wandless system, ease

of setup and use, and lack of need for skin fi ducial

placement There are several drawbacks to using

the skin fi ducial method, including the need for

placement of the fi ducials and the CT scan the

day before the operation In addition, the fi ducials

may fall off or may move after the patient is

anes-thetized and the facial musculature relaxes

Metson and colleagues reviewed their

expe-rience with both optical- and

electromagnetic-based systems in 79 patients.8 Both systems

provided an accuracy of <2 mm at the start of

the operation However, by the completion of

the operation, accuracy had deteriorated by an

average of 0.89 mm due to anatomical drift

Even at this accuracy level the authors thought

both systems were useful This is because, when

properly used, image-guidance systems should

be used to identify larger and not to distinguish

margins of safety at a millimeter level

Disadvan-tages of the system include increased operating

room time and expense CGESS increased the

mean total operating room time by 17.4 minutes

However, the actual operating time was not

pro-longed since the time required to set up, calibrate,

and register the system was carried out before

the start of the operation In addition, the time

represented a mean, and once operating room

personnel became familiar with the system this

value was reduced to less than 10 minutes With

regard to expense, the authors calculated that use

of CGESS increased total charges by $496 per

operation due to the increased operating room

time Because of the increased time and expense

associated with CGESS, the authors do not

rec-ommend it for routine head and neck cases

Current indications for image-guided sinus

surgery (IGSS) are as follows:

1 Revision sinus surgery

2 Distorted sinus anatomy of developmental,

postoperative, or traumatic origin

3 Extensive sinonasal polyposis

4 Pathology involving the frontal, posterior moid, or sphenoid sinuses

eth-5 Disease abutting the skull base, orbit, optic nerve, or carotid artery

6 CSF rhinorrhea or conditions where there is a skull-base defect

7 Benign and malignant sinonasal neoplasms

(“Intraoperative use of computer-aided gery: AAO-HNS Policy on Intraoperative use of computer-aided surgery,” American Academy of Otolaryngology—Head and Neck Surgery)

sur-Several articles have been published since the introduction of the technology in the 1990s;

however, to date, there is limited evidence that the intraoperative use of IGSS reduces com-plications and/or improves clinical outcomes

Recently, a systematic review of the based literature was performed to address these issues.9 The authors concluded that randomized clinical trials of IGSS are not practical, ethical,

evidence-or feasible and that clinical experience, expert opinion, and case series support the current indi-cations for IGSS In addition, studies designed

to draw conclusions regarding the role of IGSS

in decreasing major complications are not sible

pos-At the Medical College of Wisconsin, an cal-based, computerized image-guidance system (Stealth with LandmarX software) is set up, cali-brated, and registered as follows.10 The patient undergoes a preoperative image-guided CT scan without fi ducials During the induction of anes-thesia, the system is set up and the CT data are loaded onto the computer Once the patient is asleep, topical decongestants are placed in the sinonasal cavity While waiting for decongestion

opti-to occur, the image-guided headset is placed The patient is subsequently prepped and draped The endoscopes and instrumentation is set up and local anesthetic (1% lidocaine, 1:100,000 epinephrine)

is injected into the side to be operated on fi rst

While allowing vasoconstriction to occur, the registration is carried out using the tracer contour technique which takes less than a minute

Once accurate registration is obtained (< 2 mm), CGESS commences In most cases, this takes less than 2 minutes to accomplish, and

we still wait another 3 to 5 minutes for striction Thus, although it could be argued this process adds to operating room time, it is sub-stantially less than 5 minutes of net additional time

vasocon-We have found the system to be most useful in cases requiring frontal sinus ventilation, revision surgery, repair of skull base defects, and resection

of sinonasal neoplasms.10 The instrumentation, which can currently be integrated, is particularly useful in the endoscopic approach to the frontal sinus CGESS should be viewed as a means to help identify spaces within the sinonasal cavity, not to measure millimeter increments (Figures 1 and 2) In addition, it is not a replacement for sound surgical technique, anatomic knowledge, and experience

SURGICAL SIMULATORS

Simulation is becoming accepted in the cal community as an alternative in surgical skill training In large part, this trend evoked due to the large number of medical errors identifi ed in

surgi-the Institute of Medicine’s report entitled To Err

Is Human: Building a Safer Health System This

publication estimated that between 44,000 and 98,000 patients die as a result of medical errors annually One of the mechanisms cited by the authors to reduce medical errors is to incorporate simulation into surgical training.11

In addition to “learning by doing,” cadaveric and live animal dissections and procedures have been historically utilized to facilitate surgical development; however, limitations on the avail-ability of these resources (as well as cost) limit these as long-term solutions In addition, they may not represent the best models for many types

of human surgery and techniques.12 Computer simulation has been used successfully in other

fi elds for pilot and astronaut training, in military exercises, and for nuclear power plant operations training Although the initial costs may be larger, the long-term costs may be less than those associ-ated with the more traditional training methods noted above Advantages of simulation include the reality that there is no risk to patients, it is always available, tasks can be practiced repeat-edly without concern for materials or cost, and the potential for objective monitoring of surgeon profi ciency and progress exists

Endoscopic sinus surgery has become the treatment of choice for those patients who fail medical therapy for chronic rhinosinusitis While conceptually quite simple, performing endoscopic sinus surgery safely and effectively is quite chal-lenging.13 Successful completion of endoscopic sinus procedures depends on a detailed knowl-edge of the relevant anatomy, as well as the abil-ity to effectively manipulate the endoscope and instruments within the tight confi nes of the nose and paranasal sinuses Furthermore, the close proximity of several vital structures including the brain, orbit, and internal carotid artery adds to the diffi culty These procedures require coordination

of the endoscopes with the surgical instruments in

a three-dimensional (3-D) space which requires the development of complex ambidextrous per-ceptual, visuospatial, and psychomotor skills for which virtual reality simulators are gaining acceptance as means of training.14 This skill set is quite different than that needed to perform open surgical procedures

The endoscopic sinus surgery simulator (ES3) was developed by Lockheed Martin Corporation and has been investigated as an adjunctive train-ing tool in otolaryngology residency programs

Glaser and colleagues demonstrated that the ES3 provided medical students with signifi cant sub-jective training benefi ts as well as objectively measured performance benefi ts.15 Thus, they concluded that the ES3 holds much promise

as a training tool in the development of scopic sinus surgery skills Further development