title: Evaluating craniofacial asymmetry with digital cephalometric images and cone-beam computed tomography.
abstract: BACKGROUND
  The aim of this study was to evaluate craniofacial asymmetry by using 2-dimensional (2D) posteroanterior cephalometric images, 3-dimensional cone-beam computed tomography (CBCT), and physical measurements (gold standard).
  
  
  METHODS
  Ten dry human skulls were assessed, and radiopaque markers were placed on 17 skeletal landmarks. Twenty linear measurements were taken on each side to compare the right and left sides and to compare these measurements with the physical measurements made with a digital caliper. To acquire the 2D posteroanterior radiographs, an Extraoral Phosphor Storage Plate (Air Techniques, Chicago, Ill) was used as the image receptor with a Eureka x-ray-Duocon Machlett unit (Machlett Laboratores, Chicago, Ill). Three-dimensional imaging data were acquired from a CB MercuRay (Hitachi Medical, Tokyo, Japan).
  
  
  RESULTS
  On average, the right side was larger than the left for most of the 20 distances evaluated in the digital 2D and the CBCT images, and there was poor agreement between the digital 2D images and the physical measurements (kappa = 0.0609) and almost perfect agreement (kappa = 0.92) between the CBCT and physical measurements when individual measurements were considered.
  
  
  CONCLUSIONS
  Human skulls, with no apparent asymmetry, had some differences between the right and left sides, with dominance for the right side but with no clinical significance. CBCT can better evaluate craniofacial morphology when compared with digital 2D images.
authors.affiliation: Discipline of Radiology, Department of Diagnostic and Surgery, São Paulo State University-UNESP, São José dos Campos, São Paulo, Brazil. eli@fosjc.unesp.br
authors.forename: Mari Eli Leonelli
authors.initials: ME
authors.lastname: de Moraes
authors.forename: Lars G
authors.initials: LG
authors.lastname: Hollender
authors.forename: Curtis S K
authors.initials: CS
authors.lastname: Chen
authors.forename: Luiz C
authors.initials: LC
authors.lastname: Moraes
authors.forename: Ivan
authors.initials: I
authors.lastname: Balducci
mesh_terms: D002508:Cephalometry / Q000592:standards*; D002680:Chin / Q000033:anatomy & histology; D054893:Cone-Beam Computed Tomography / Q000592:standards*; D005146:Facial Asymmetry / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005147:Facial Bones / Q000033:anatomy & histology*; D057918:Fiducial Markers; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000592:standards*; D008334:Mandible / Q000033:anatomy & histology; D008335:Mandibular Condyle / Q000033:anatomy & histology; D008437:Maxilla / Q000033:anatomy & histology; D009295:Nasal Bone / Q000033:anatomy & histology; D009296:Nasal Cavity / Q000033:anatomy & histology; D009915:Orbit / Q000033:anatomy & histology; D011856:Radiographic Image Enhancement / Q000295:instrumentation / Q000379:methods; D012658:Sella Turcica / Q000033:anatomy & histology; D012886:Skull / Q000033:anatomy & histology*; D012984:Software; D014963:X-Ray Intensifying Screens; D015050:Zygoma / Q000033:anatomy & histology