title: Observer reliability of three-dimensional cephalometric landmark identification on cone-beam computerized tomography.
abstract: OBJECTIVE
  To evaluate reliability in 3-dimensional (3D) landmark identification using cone-beam computerized tomography (CBCT).
  
  
  METHODS
  Twelve presurgery CBCTs were randomly selected from 159 orthognathic surgery patients. Three observers independently repeated 3 times the identification of 30 landmarks in the sagittal, coronal, and axial slices. A mixed-effects analysis of variance model estimated the intraclass correlations (ICC) and assessed systematic bias.
  
  
  RESULTS
  The ICC was >0.9 for 86% of intraobserver assessments and 66% of interobserver assessments. Only 1% of intraobserver and 3% of interobserver coefficients were <0.45. The systematic difference among observers was greater in X and Z than in Y dimensions, but the maximum mean difference was quite small.
  
  
  CONCLUSIONS
  Overall, the intra- and interobserver reliability was excellent. Three-dimensional landmark identification using CBCT can offer consistent and reproducible data if a protocol for operator training and calibration is followed. This is particularly important for landmarks not easily specified in all 3 planes of space.
authors: Department of Dentistry-I, Universidade Federal do Maranhão, Maranhão, Brazil.
authors: Ana Emilia F
authors: AE
authors: de Oliveira
authors: Lucia Helena S
authors: LH
authors: Cevidanes
authors: Ceib
authors: C
authors: Phillips
authors: Alexandre
authors: A
authors: Motta
authors: Brandon
authors: B
authors: Burke
authors: Donald
authors: D
authors: Tyndall
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000379:methods*; D054893:Cone-Beam Computed Tomography / Q000295:instrumentation; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D019767:Maxillofacial Abnormalities / Q000000981:diagnostic imaging*; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D055815:Young Adult