3. Luan An Tom Tat (Eng).Pdf

Microsoft Word Tom tat LA (Eng) 12 10 docx MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES NGUYEN THI MY HANH RESEARCH OF TREATMENT[.]

MINISTRY OF EDUCATION AND TRAINING

MINISTRY OF DEFENCE

108 INSTITUTE OF CLINICAL MEDICAL AND

PHARMACEUTICAL SCIENCES -

NGUYEN THI MY HANH

RESEARCH OF TREATMENT IN PATIENT WITH ANGLE

CLASS I MALOCCLUSION, NONEXTRACTION USING

SELF- LIGATING BRACKETS AND BROADER

ARCHWIRES

Speciality: Odonto- Stomatology

Code: 9720501

ABSTRACT OF MEDICAL PHD THESIS

Hanoi – 2023

THE THESIS WAS DONE IN: 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES

Supervisor:

1 Prof Dr Trinh Dinh Hai

2 Assoc.Prof.Dr Le Thi Thu Ha

Reviewer:

1

2

3

This thesis will be presented at Institute Council at: 108 Institute of Clinical Medical and Pharmaceutical Sciences

Day Month Year

The thesis can be found at:

1 National Library of Vietnam

2 Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences

3 Central Institute for Medical Science Infomation and Tecnology

INTRODUCTION

Malocclusion is the deviation of the relationship

between the teeth on one jaw and/or between two jaws that

affects health and is often combined with other facial

aberrations Class I malocclusion is the most common

deviation Salim's study in 2021 showed that the rate of class I

malocclusion was 52.6%, in which the rate of crowded teeth

accounted for 71.1% Crowded teeth are one of the main

reasons that patients come for examination and treatment

Non-extraction treatment is not only the desire of the patient

but also the top priority for the orthodontist

Using self-ligating brackets and broader wires to widen

the arch to the sides or widen the arch anteriorly That helps

reduce crowding in cases where teeth are not extracted The

study of Maltagliati LA and Jiang RP et al (2008) using the

Damon self-ligating bracket system and Damon's extension

archwire resulted in an increase in width in the molar area

after treatment

In our country, the technique of orthodontic treatment

with self-ligating brackets has been applied for recent years

However, no studies have been published on this issue

Therefore, we carried out the project "Research study of

treatment in patient with class I malocclusion, nonextraction

using self- ligating brackets and broader archwires" with 2

objectives:

1 Describe some clinical and radiographic characteristics of

the group of patients with class I Angle malocclusion who

are indicated for non-extraction treatment

2 Evaluation of the treatment results of these patients with

self-ligating bracket system and broader archwire

THE URGENCY OF THE THESIS

Malocclusion not only causes discord in the

relationship of the mouth and face, affecting aesthetics, but

also creates favorable conditions for many other diseases to

develop such as periodontal disease, tooth decay, and gum

disease eat … Non-extraction treatment is not only the

patient's wish but also the first priority for the orthodontist In recent years, orthodontic treatment with fixed appliances has developed rapidly Many types of fixed orthodontic appliances have been invented, giving doctors and patients more and more treatment options The use of the self-ligating bracket system and broader archwire helps to reduce tooth crowding in cases where no extraction is possible In Vietnam, this technique has been applied but no research has been published, so the topic is urgent, topical and has scientific significance

PRACTICAL MEANS AND NEW CONTRIBUTIONS

1 The study presents some clinical and radiographic characteristics of patients with class I Angle malocclusion, crowded teeth

2 Efficacy of self-ligating bracket system and broader archwires in treatment

STRUCTURE OF THE THESIS

In addition to the introduction, the thesis has 4 chapters: Chapter I – Research overview – 37 pages, Chapter II – Research objects and methods – 23 pages, Chapter III – Results – 30 pages, Chapter IV – Discussion – 37 pages The thesis has 25 tables, 09 charts, 33 pictures, 127 references (98 English, 29 Vietnamese)

CHAPTER I RESEARCH OVERVIEW

1.1 Class I malocclusion Class I malocclusion: the mesial lateral cusps of the maxillary first permanent molars align with the mesial lateral sulcus of the mandibular first permanent molars, but the occlusal line is not due to anterior teeth growing out of place, rotating teeth , or other causes

1.2 Epidemiology

In Vietnam: a study by Vuong Ngoc Thin et al in 2018 showed that class I malocclusion accounted for the highest rate with 41.7%; Nguyen Trong Hoa's study on a group of students in South Korea showed that the normal occlusion rate

accounted for 6.7%; Class I malocclusion accounted for

22.4%; Nguyen V A study on the occlusal status of

12-year-old children showed that the rate of class I occlusion was

62.2%

In the world: Research by Lin et al published in 2018

showed that the rate of class I malocclusion was 30.07%;

crowded teeth accounted for 49.2%; Xu et al.'s study

published in 2019 showed that class I Angle malocclusion has

a rate of 30.96%; In 2019, Sundareswaran announced research

results on the rate of class I malocclusion is 89.9%; Salim's

study published in 2021 showed that the rate of class I Angle

malocclusion was 52.6%

1.3 Clinical and radiographic characteristics of Class I Angle

malocclusion, crowded teeth, no extraction

1.3.1 Clinical characteristics

* Frontal views: usually has a medium or short face

shape, the facial layers are symmetrical or slightly different,

normally at rest, the lips are slightly touching, the muscles

around the mouth are completely relaxed, the upper front teeth

are exposed about 1 -5mm

* Profile: usually straight or convex Angle of nose and

lips: created by two lines passing through the point of the base

of the nose wing, tangent to the curve connecting the tip of the

nose to the base of the nose and the line tangent to the upper

lip The mean value of this angle is 100 0 ± 10, the nasolabial

angle is one of the criteria to consider, evaluate and make the

decision to extract teeth or not to extract teeth in orthodontic

treatment

* Occlusal characteristics:

- Malocclusion in the anteroposterior direction: The

mesial lateral cusps of the maxillary first permanent molars

match the mesial lateral grooves of the mandibular first

permanent molars, but the occlusion line is not correct due to

the eruption of the anterior teeth, misplaced rotated teeth, or

other causes

- Sagittal: Class I malocclusion is often accompanied

by malocclusion such as deep bite, open bite or midline

deviation

- Horizontal: The patient may have a normal posterior

occlusal relationship or a narrow jaw leading to a posterior crossbite

- In each arch: Crooked teeth, rotated teeth, redundant

teeth, stuck teeth, hidden teeth, misplaced teeth, deformed teeth are common features in class I malocclusion

1.3.2 Indicators on cephalometric radiographs 1.4 Treatment of class I malocclusion

Extraction or not is a controversial issue in the history

of orthodontics

According to W Profit: The degree of deficiency is about <4mm: nonextraction; 5 – 9mm: can be extracted or not extracted; >10mm: extraction

Bowman asserted that there are many reasons to extract spacers in orthodontics such as crooked, deep Spee curve, deep bite, midline deviation etc The most important factor to determine is the patient 's profile Normally, the angle formed

by the maxillary incisor and the lower mandibular incisor axis

is 125-1310 Non-extraction treatment solutions: expansion, distalization, interproximal reduction

Distalization: When choosing to distalize, the following factors should be considered: distance allowed to travel;

correlation between the upper teeth and the jaws of the maxillary sinuses; ertical correlation: Open correlation is generally contraindicated for distal migration because it can cause an open bite and worsen facial elongation

Interproximal reduction: commonly applied in adults,

the size difference between the two jaws is a favorable factor

in the decision of tooth grinding Interstitial grinding is only limited to the tooth enamel, the level of interstitial grinding allows each tooth to be about 0.5mm

Expansion: If the posterior teeth are tilted inward with clinical presentation of posterior crossbite, this is a favorable factor Dilating the jaw area by 1mm will solve 1mm of crowding Orthodontic expansion can use dental or bone expansion methods

Beside dental dilators, use of self-ligating brackets and

extension cords to widen the dental arch to the sides when

placing the stopper in its original position or expanding the

arch comes out first when placed on the side near the first

small tooth

1.5 Self-ligating brackets

1.5.1 Definition: is a bracket system designed with a wire

retention system right on the brackets, without the need for

elastics or ligatures to hold the arch wire

1.5.2 The philosophy of the self-ligating bracket system:

Light force is the key to self-ligating Light force, low friction

helps teeth move physiologically without resisting the body

and does not disrupt the blood vessels that nourish the area

around the teeth

1.5.3 Classification of self-ligating brackets

Self-ligating brackets are divided into two types: passive

brackets and active brackets

1.5.4 Structure

Just like normal brackets, including: bracket base,

bracket body (including bracket wing, bracket slot and

auxiliary components, only the difference is that there is an

additional locking element to keep the arch wire in place used

instead of elastic bands or metal ligatures)

1.5.5 Studies on self-ligating brackets

In the world: According to research by Kiem et al., the

use of self-ligating brackets in orthodontic treatment is

increasing The first advantage of the self-ligating bracket

system compared to the conventional bracket system is to

reduce friction The study by Jahanbin et al showed that the

adjustment time of self -ligating brackets was lower than that

of traditional braces and the type of brackets did not affect the

patient 's pain sensation According to Al-Ibrahim et al

announced in 2021, using self-ligating brackets helps to

reduce treatment time by 25 % compared to using traditional

brackets The study of Maltagliati LA and Jiang RP et al

(2008) using Damon's self-ligating bracket system and

Damon's extension cord showed that the width in the denture

area increased after treatment

Vietnam: No studies on self-ligating brackets have been reported

1.6 Archwire Definition: The archwire is the main force-generating material in orthodontics, either by attaching to the brackets or can be placed outside the brackets

Classification of archwires: There are many ways to classify archwires, archwires can be classified by: shape (triangle, oval, square); Metal components in the wire core (stainless steel metal wire, Themaloy, NiTi wire, Beta-titanum); Dimensions (0.012inch; 0.013inch; 0.014inch; 0.016inch; 0.16 x 0.22 inch, ); Fabrication materials (metal wire, non-metallic wire, fiber reinforced composite bowstring )

Broader archwires: A new type of Nitium string developed by Ormco in 1994 called Copper Nitium, by adding

a copper amount of about 5 % and a small amount of Chromium (0.2-0.5) %) into a Nitium alloy, which helps to increase the ductility and elasticity of the wire, called superelastics Copper Nitium wire is usually made in the form

of a wide arc, used for self-ligating brackets for the purpose of widening the arc

CHAPTER 2 RESEARCH SUBJECTS AND METHODS

2.1 Research object Subjects of the study are patients who come for examination and treatment at National Hospital of Odonto-Stomatology, Hanoi, are Vietnamese people, Kinh ethnic group

2.1.1 Selection criteria: Vietnamese people voluntarily participate in the study; Diagnosed with Class I Angle malocclusion with: Permanent teeth, with one or more crowded teeth, degree of deficiency < 10mm, Angle of nose and lips: 97,410 ± 8,000 (female), 91,670 ± 7,550 (male), Interlock angle: 119,740 ± 7,810(female), 121,440 ± 7,720(male)

2.1.2 Exclusion criteria: Congenital malformations in the

maxillofacial region, permanent missing teeth (excluding the

third molars); Patients with indications for orthopedic surgery;

Patients with mental disorders; Patients with periodontal

disease; The patient did not consent to participate in the study

2.2 Research Methods _

2.2.1 Study design: Cross-sectional descriptive study for

objective 1 and non-controlled clinical intervention study,

evaluating the results before and after for objective 2

2.2.2 Study sample size

Apply the formula to calculate the sample size based on

the success rate of the treatment

n = Z 2

1- α /2

n: Study sample size

Z 1- α /2: Number of standard error from mean

(confidence coefficient), with α = 0.005 we have Z 1- α /2 =1.96

d: Desired accuracy, choose d = 0.1

Success rate of orthodontic treatment according to Kerr:

p =89%

Applying into the formula we get n = 38

2.3 Time and place of study

The study was conducted from October 2016 to January

2023 Location: Orthodontic Department - National Hospital

of Odonto-Stomatology, Hanoi, 108 Institute of clinical

medical and pharmaceutical science

2.5 Steps for procedure

2.5.1 Step 1: Examination and diagnosis

The patient is classified as occlusal, if there is a class I

malocclusion, treatment is indicated without extraction, then

proceed to step 2

2.5.2 Step 2: Introduce, invite to participate in the study

Patients (or representatives of children <18 years of age) were

fully introduced to the study, and could ask anything related

to the study

2.5.3 Option 3: Clinical examination

2.5.4 Step 4: Analyze the radiography

Take cephalometric and panoramic Then, measure and analyze the cephalometric on Wedceph online software

2.5.5 Estimation 4: Sample analysis, evaluation of PAR index 2.5.6 Step 6: Diagnosis and treatment planning

2.5.7 Step 7: Initiate treatment

- Pre -orthodontic treatment: Treatment of deeply damaged teeth, pulpitis; scaling/clean dental plaque, treat gingivitis

- Orthodontic treatment: All patients were treated with passive self-ligating brackets and broader archwire

- End of treatment: Remove brackets, patients can take retainers for the next 1 year

2.5.8 Step 8: Collect data after treatment

Take dental impressions, take samples and measure the width of the jaws, measure the PAR index at the end of treatment, take panorama, side-by-side films, and analyze lateral skull films at the end of treatment Comparison of results before and after treatment

2.6 Analyze the results

2.6.1 Clinical and radiographic characteristics of the subjects

2.6.1.1 Clinical features 2.6.1.2 Radiographic characteristics

2.6.2 Evaluation of treatment results

2.6.2.1 Occlusion: The study used the PAR index to evaluate the results of treatment of malocclusion

2.6.2.2 Evaluation of the change in the width of the teeth before and after the treatment

2.6.2.3 Evaluation of changes in bones, teeth, and soft tissue

on cephalometrics 2.6.2.4 Assess the level of patient satisfaction about the duration of treatment and the results after treatment

2.6.2.5 Criteria for evaluating the results: achieving a good occlusion and a harmonious face

2.6.3 Data analysis: The indicators used in the study were processed by STATA 13.0 software

2.6.4 Reliability and accuracy of the research method

Cephalometrics were measured using Webceph

software by one person The film is taken digitally and sent to

a soft file or Scan to the doctor to measure the film on

Webceph software All patients were diagnosed and treated

according to the procedure by a doctor from the beginning to

the end of the treatment

Plaster sample: The sample must be left to dry,

preserving the sample to avoid chipping and breaking When

marking landmarks, use a needle pen (0.5 mm) Measuring

instrument: Digital electronic estimator with 0.01 mm

accuracy, measured on each function sample twice, each time

the estimator must be recalibrated take the average value

Make a spreadsheet of the Pearson correlation coefficient (r)

and compare it with the standard classification of the British

statistician Karl Pearson to evaluate the Pearson correlation

coefficient Measure to get data when Pearson correlation

coefficient ≥ 0.8

2.6.5 Research ethics

All subjects participating in the study were informed,

fully understood the purpose of the study, voluntarily

participated in the study, had the right to refuse to participate

in the study at any time The research results are used only for

research purposes and to ensure the confidentiality of the

research subjects ' information

CHAPTER 3: RESULTS

3.1 Clinical and radiographic characteristics of Class I

Angle malocclusion, with indications for non-extraction

treatment

3.1.1 Characteristics of research subjects

Chart 3.1 Distribution of patients by gender There are 39.47% male patients and 60.53% female patients

Chart 3.2 Distribution of patients according to age group

There are 47.37% patients between 12 and 15 years old; 28.95% from 9 to under 12 years old and 23.68% over 15 years old

The mean age was 13.18 ±2.67

3.1.2 Facial features

Chart 3.3 Face types There are 84.22% patients with mesofacial; 7.89%

patients with dolichofacial and 7.89% patients with brachyfacial

39,47%

60,53%

Male Female

28,95%

47,37%

23,68%

9-<12 years old 12-15 years old

>15 years old

84,22

0 20 40 60 80 100

Chart 3.4 Facial profile types

81.58% patients have convex face type; 15.79% have straight

type; 2.63% patients with concave type

Chart 3.5 Facial symmetry

There are 89.48% of subjects with symmetrical faces; 5.26%

have a left asymmetrical faces and 5.26% have a right

asymmetrical faces

3.1.3 Characteristics of teeth, dental arches and joints bite

Chart 3.6 The shape of the dental arch in the study group

of patients

15,79

81,58

2,63

0

50

100

Series 1

89,48%

5,26%

Left asymmetry Right asymmetry

0

50

100

150

86.84% of patients had oval maxillary arches; 7.89% have square dental arches and 5.26% triangular dental arches

Table 3.2 Occlusion characteristics

Average overbite 3.14 ± 1.75

Average bite 2.63 ± 1.34

44.74% of patients have deep bite; 31.58% have crossbite;

13.16% of patients with open bite and 13.16% of patients with confrontational bite 26.32% of patients had midline deviation The average overbite is 3.14 ±1.75 mm; average bite coverage is 2.63 ±1.34mm

Table 3.4 Width of dental arch before treatment

Variabl

e

23)

P

U3-U3 35.23 2.60 34.77 2.54 35.53 2.64 0.1779 U4-U4 42.18 2.86 42.97 3.27 41.67 2.49 0.2334 U5-U5 48.30 2.77 49.07 2.82 47.80 2.69 0.2278 U6-U6 52.26 2.52 53.20 1.65 51.64 2.82 0.2316 L3-L3 27.59 2.13 28.42 1.79 27.05 2.19 0.2564

L -L4 34.80 2.20 35.38 2.55 34.43 1.90 0.2279 L5-L5 40.82 2.45 41.42 1.93 40.43 2.71 0.2254 L6-L6 45.30 2.22 46.03 1.75 44.82 2.40 0.2280

The width of the dental arch at positions increases gradually

from tooth area 3 to tooth area 6; There was no statistically significant difference between men and women

Chart 3.7 Degree of space deficiency in the upper jaw

71.05% of patients have a deficiency of about <5 mm; 28.95%

of patients have a deficiency of about 5-10mm

Chart 3.8 Degree of space deficiency in the lower jaw

In the lower jaw of the study group, the degree of deficiency

of about < 5mm accounted for the highest rate with 78.95%

(30 patients), the degree of deficiency of about 5 - 10mm had

the rate of 21.05% (with 8 patients) patient)

Table 3.5 PAR index before treatment

(mm)

Min Ma

x

SD

Crooked front top and

bottom

Crooked area behind the

top and bottom

Correlation of posterior

occlusal

71,050%

28,950%

< 5mm

5 - 10mm

78,95%

21,05%

< 5mm

5 - 10mm

Table 3.7 Midline deviation

Variable

deviation (mm)

Lower jaw 15 39.47 1,77 ± 0,56 23 60.53

There are 26.32% patients with deviated maxillary midline; 39.47% of patients had a deviated mandibular midline The average deviation of the maxillary midline was 1.6 ±0.84 (mm); the average deviation of the midline of the lower jaw is 1.77 ±0.56 (mm);

Figure 3.9 Total PAR (W) before treatment 34.21% of patients had PAR(W) from over 20 to 30; 31.58%

had a PAR(W) between 10 and 20; 26.32% have PAR(W) over 30; PAR(W) ≤ 10 has the lowest rate with 7.89%

7,89%

31,58%

34,21%

10< PAR(W) ≤ 20 20< PAR(W) ≤ 30 PAR(W) > 30

3.1.4 Characteristic X-ray

Table 3.8 Bone correlation indexes before treatment

on slanted skull film

Variable

Shared

(n=38)

Male (n=15) Female

(n=23)

p

Mea

n

n

n

SD

SNA 81.82 2, 60 81.46 2.67 82.06 2.58 0.1909

SNB 79.02 2.82 78.68 2.69 79.25 2.94 0.1912

ANB 2.80 1.13 2.78 0.82 2.81 1.31 0.2191

NPog-FH 88.70 3.22 87.94 3.69 89.19 2.86 0.1843

FMA 23.31 5.3 1 24.49 5.59 22.55 5.09 0.3106

The indices of SNA, SNB, ANB, face angle (NPog-FH)

of women are higher than that of men, indexes of surface

elevation (NA-Apog), lower face height (ANS-Me), and FMA

of men are higher than that of men women, but this difference

was not statistically significant

Table 3.9 The index of correlation teeth - bones, teeth -

teeth

before treatment on cephalometric radiographs

Variabl

e

Shared (n=38)

Male (n=15)

Female (n=23)

p

U1-NA

(mm)

5.44 2.12 5.29 2.43 5.53 1.95 0.1849

U1-NA

( ॰)

28.17 5.09 28.05 5.37 28.24 5.02 0.1985

U1-APo

7.51 2.25 7.49 2.68 7.53 1.98 0.2128

L1-NB (mm)

5.77 1.98 5.98 2.07 5.63 1.95 0.2938

L1-NB ( ॰)

28.18 5.93 28.64 6.50 27.89 5.66 0.2376 FMIA , IMPA, U1-L1, U1 - SN , U1-NA (mm), U1-NA (॰) , U1-A Po in women are higher than in men; L1 -NB (mm), L1-NB (॰) , L1-A Po in men are larger than women but this difference is not statistically significant

Table 3.10 Pre-treatment soft tissue indices on cephalometric radiographs

Variable

Shared (n=38)

Male (n=15)

Female (n=23)

P

Corner nose lip

93.53 5.19 91.26 4.57 95.49 5.62 0.2373

Gla-Sn-Pog'

169.98 4.23 170.48 3.80 169.66 4.53 0.2035

3 6.83 1.87 5.52 1.82 0.5387

9 40.00 3.42 0.2404

30 11.99 2.69 11.23 2.01 0.2859

Most indicators soft tissue angles on lateral

cephalometric radiographs such as nasolabial fold, facial

angle (G-Sn-Pog'), Ls- E, Li-E, upper lip protrusion

(Ls-TVL), lower lip protrusion (Li-TVL ) , upper lip length

(Sn-Sts), upper lip thickness (Ls-max), lower lip thickness

(Li-max) lower chin thickness (Me-Me') is greater in men than in

women with only chin protrusion (Pog'-TVL) and anterior

chin thickness (Pog-Pog') were larger in women than in men,

this difference was not statistically significant

3.2 Evaluation of treatment results

3.2.1 Evaluation of the difference before and after

treatment based on analysis of gypsum samples calculated

according to PAR index

Table 3 12 Percentage of improvement in PAR (W)

Level of improvement PAR (W)

There were 94.74% patients with good PAR(W)

improvement; None of the patients had a poor improvement

3.2.2 Evaluate the difference before and after treatment

based on measuring the arch width on plaster samples

Table 3.14 Change of arch width before and after

treatment

treatment

After treatment

The width of the dental arches in the canines, premolars and molars in both the upper and lower jaws increased statistically significantly compared to before treatment (p < 0.05) The change was greatest in the first premolar region and least in the canine region

3.2.3 Evaluate the difference before and after treatment based on analysis of lateral cranial films

Table 3.15 Changes in bone correlation indexes before and after treatment on cephalometric radiographs

treatment

After treatment

SNA 38 81.82 ± 2.60 81.96 ± 2.85 0.14 0.3339

SNB 38 79.02 ± 2.82 79.01 ± 3.0 4 -0.01 0.9185

ANB 38 2.80 ± 1.13 2.95 ± 1.4 9 0.15 0.3048

NPog-FH

38 88.70 ± 3.22 88.61 ± 3.37 -0.09 0.7233

NA-APog

38 5.77 ± 3.30 5.55 ± 4.00 -0.22 0.5551

FMA 38 23.31 ± 5.3 1 23.93 ± 6.22 0.62 0.2850 The indexes of bone correlation after treatment were almost unchanged compared to before treatment

Table 3.16 The change of tooth correlation indexes before and after treatment on lateral cephalometric radiographs

treatment

After treatment

U1-NA (mm)

38 5.44 ± 2.12 5.65 ± 1.82 0.21 0.6040

U1-NA ( ॰) 38 28.17 ± 5.09 28.22 ± 6.33 0.05 0.9566

L1-NB (mm)

38 5.77 ± 1.98 6.75 ± 1.64 0.98 0.0015

L1-NB ( ॰) 38 28.18 ± 5.93 30.24 ± 4.30 2.06 0.0339