accuracy and reliability of 2d cephalometric analysis in orthodontics

Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial Original research Ana R.. Ferreiraf, Reinhilde Jacobsc aDepartment of Dental Radiology, Faculty of Dental M

Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial

Original research

Ana R Durãoa, ∗, Napat Bolstadb, Pisha Pittayapatc,d, Ivo Lambrichtse,

Afonso P Ferreiraf, Reinhilde Jacobsc

aDepartment of Dental Radiology, Faculty of Dental Medicine, University of Porto, Porto, Portugal

bDepartment of Clinical Dentistry, Faculty of Health Science, UiT The Arctic, University of Norway, Tromsø, Norway

cOral Imaging Center, OMFS-IMPATH Research Group, Dept of Imaging & Pathology, Faculty of Medicine, University of Leuven, Leuven, Belgium

dDepartment of Radiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand

eBiomedical Research Institute, Laboratory of Morphology, Hasselt University, Campus Diepenbeek, Diepenbeek, Belgium

fDepartment of Orthodontics, Faculty of Dental Medicine, University of Porto, Portugal

a r t i c l e i n f o

Article history:

Keywords:

Cephalometry

Orthodontics

Radiography

Skull

Accuracy

Reliability

a b s t r a c t

Objectives: Toevaluatetheaccuracyoftwo-dimensional(2D)cephalometricanalysiswhen

Methods:Twentydryhumanskullsanditsdigitallateralcephalometricimagesofweretaken

Results:Statisticallysignificantdifferenceswerefoundbetweencephalometricanddirect

Conclusion: Radiographiclinearmeasurementssystematicallyoverestimatedthedirect

planning

∗ Corresponding author.

http://dx.doi.org/10.1016/j.rpemd.2014.05.003

Fiabilidade da análise cefalométrica em 2D em ortodontia

Palavras-chave:

Cefalometria

Ortodontia

Radiografia

Crânio

Precisão

Fiabilidade

r e s u m o

Objectivos:Paraavaliaraprecisãodaanálisecefalométricabidimensional(2D)quando

Métodos: Vintecrânioshumanossecoseforamtiradasfotografiasdasuacefalometria

Resultados: Foramencontradasdiferenc¸asestatisticamentesignificativasentreasmedic¸ões

Conclusão: As medic¸ões lineares radiográficas sobrestimaram sistematicamente as

Introduction

Fig 1 – The picture shows a skull stabilized in the

cephalostat on an aluminum filter cylinder.

measurements

Results

Table 1 – Linear measurements evaluated on both human skulls and lateral cephalometric radiographs in this study.

Linearmeasurements(mm) Totalanteriorfaceheight:N-Me Upperfaceheight:ANS-N Lowerfaceheight:ANS-Me Mandibularunitlength:Co-Gn Maxillaryunitlength:Co-ANS AN:AtoNwithrespecttotruevertical BN:BtoNwithrespecttotruevertical PogN:PogtoNwithrespecttotruevertical Po-Or(Frankfortplane)

Go-Me(mandibularplane)

Po Co

Go

Or N

ANS A

B Pog

Me Gn

Po Co

Go

Or N

ANS A

B Pog

Me Gn

Fig 2 – Cephalometric landmarks used in the study N – Nasion; Me – Menton; ANS – Anterior Nasal Spine; Co – Condylion;

Gn – Gnathion; A – Point A; B – Point B; Pog – Pogonion; Po – Porion; Or – Orbitale; Go – Gonion.

Discussion

Table 2 – Mean differences between the first and second observations with regard to intra-observer agreement (mm).

N-Me

Skull 10.08(0.96) 0.999 0.997–0.999 −0.10;0.09 10.08(0.96) 0.998 0.995–0.999 −0.11;0.12 Radiograph 11.02(1.01) 0.978 0.948–0.991 −0.47;0.36 11.03(1.02) 0.999 0.998–1.000 −0.06;0.09

ANS-N

Radiograph 4.79(0.35) 0.905 0.786–0.960 −0.36;0.25 4.82(0.32) 0.831 0.636–0.926 −0.49;0.39

ANS-Me

Radiograph 6.38(0.82) 0.984 0.961–0.993 −0.34;0.24 6.43(0.83) 0.973 0.937–0.989 −0.49;0.26

Co-Gn

Skull 10.87(0.89) 0.989 0.974–0.996 −0.31;0.20 10.85(0.87) 0.994 0.985–0.997 −0.25;0.13 Radiograph 10.72(0.93) 0.989 0.973–0.995 −0.28;0.27 10.71(0.90) 0.982 0.957–0.992 −0.36;0.32

Co-ANS

Radiograph 8.54(0.57) 0.935 0.851–0.973 −0.40;0.42 8.61(0.50) 0.845 0.663–0.933 −0.72;0.43

A-N

Radiograph 5.31(0.36) 0.797 0.573–0.911 −0.51;0.45 5.39(0.35) 0.619 0.276–0.822 −0.58;0.76

B-N

Radiograph 9.25(0.76) 0.991 0.979–0.996 −0.20;0.20 9.39(0.82) 0.984 0.962–0.993 −0.27;0.31

Pog-N

Radiograph 10.29(0.95) 0.982 0.956–0.992 −0.34;0.38 10.29(0.97) 0.991 0.978–0.996 −0.26;0.25

Po-Or

Radiograph 7.42(0.40) 0.957 0.900–0.982 −0.28;0.18 7.50(0.38) 0.906 0.789–0.960 −0.36;0.30

Go-Me

Radiograph 7.05(0.55) 0.936 0.853–0.973 −0.42;0.36 7.03(0.54) 0.952 0.889–0.980 −0.23;0.44

SD–standarddeviation;ICC–intraclasscorrelation;CI(5–95%)confidenceinterval;LA–limitsofagreement

skull

Table 3 – Inter-observer agreement (mm).

N-Me

Skull 10.08(0.96) 0.997 0.993–0.999 −0.14;0.14 10.07(0.95) 0.999 0.998–1.000 −0.07;0.08 Radiograph 11.02(1.00) 0.972 0.934–0.988 −0.52;0.43 11.04(1.01) 0.996 0.900–0.998 −0.16;0.20

ANS-N

Radiograph 4.78(0.32) 0.855 0.684–0.937 −0.40;0.32 4.83(0.39) 0.861 0.694–0.940 −0.45;0.38

ANS-Me

Radiograph 6.36(0.82) 0.953 0.890–0.980 −0.51;0.49 6.44(0.82) 0.985 0.965–0.994 −0.36;0.20

Co-Gn

Skull 10.83(0.87) 0.982 0.957–0.992 −0.27;0.29 10.89(0.89) 0.994 0.986–0.998 −0.18;0.20 Radiograph 10.71(0.90) 0.978 0.947–0.991 −0.36;0.39 10.72(0.92) 0.990 0.977–0.996 −0.25;0.26

Co-ANS

Radiograph 8.55(0.55) 0.857 0.688–0.938 −0.59;0.60 8.61(0.52) 0.866 0.706–0.942 −0.72;0.43

A-N

Radiograph 5.36(0.36) 0.673 0.361–0.850 −0.77;0.49 5.33(0.35) 0.740 0.470–0.883 −0.55;0.51

B-N

Radiograph 9.33(0.79) 0.977 0.945–0.990 −0.49;0.19 9.32(0.79) 0.984 0.962–0.993 −0.41;0.14

Pog-N

Radiograph 10.29(0.96) 0.972 0.933–0.988 −0.44;0.46 10.29(0.95) 0.989 0.973–0.995 −0.26;0.26

Po-Or

Radiograph 7.45(0.39) 0.944 0.871–0.976 −0.35;0.16 7.48(0.39) 0.873 0.720–0.945 −0.47;0.32

Go-Me

Radiograph 7.06(0.51) 0.901 0.778–0.958 −0.50;0.42 7.02(0.57) 0.950 0.883–0.79 −0.27;0.45

SD–standarddeviation;ICC–intraclasscorrelation;CI(5–95%)confidenceinterval;LA–limitsofagreement

to−0.74,whichiswithintheclinicallyacceptablelimits,since

itisinferiorto1mm(Table4

skulls

Table 4 – Mean of differences and level of agreement between the measurements performed on the skull and radiography.

p–one-sample t-test;LA–limitsofagreement

structuresconfusestheidentification ofcertain landmarks, suchasCo,OrandPo,onradiographs

Thereisalwaysadegreeofmagnificationonradiographs, causedbythevariabledistancebetweentheX-raysourceand theimagereceptor.Thus,exactsuperimpositionoftheright

Conclusions

Protection of human and animal subjects.The authors

Confidentiality of data.Theauthorsdeclarethattheyhave

Right to privacy and informed consent.Theauthorsdeclare

r e f e r e n c e s

1971;60:111–27

1994;16:110–20

1993;15:79–84

6]