title: Plane orientation for standardization in 3-dimensional cephalometric analysis with computerized tomography imaging.
abstract: BACKGROUND
  The purpose of this study was to propose certain landmarks and planes to standardize 3-dimensional image orientation.
  
  
  METHODS
  Cone-beam computerized tomographic images were obtained from 10 adolescent patients and analyzed with AMIRA software (AMIRA, Mercury Computer Systems, Berlin, Germany).
  
  
  RESULTS
  Four points (ELSA, right superior external auditory meatus, left superior external auditory meatus, and mid-dorsum foramen magnum) were located on each image. The axial-horizontal plane (x-y plane) was then determined by using both superior external auditory meatus and ELSA; the sagittal-vertical plane (z-y plane) was formed by ELSA and mid-dorsum foramen magnum perpendicular to the x-y plane.
  
  
  CONCLUSIONS
  All points had high intrareliability and were adequate for standardizing the orientation of 3-dimensional images.
authors: Orthodontic Graduate Program, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada. mlagravere@yahoo.com
authors: Manuel O
authors: MO
authors: Lagravère
authors: Lars
authors: L
authors: Hansen
authors: Winfried
authors: W
authors: Harzer
authors: Paul W
authors: PW
authors: Major