title: Superimposition of 3-dimensional cone-beam computed tomography models of growing patients.
abstract: BACKGROUND
  The objective of this study was to evaluate a new method for superimposition of 3-dimensional (3D) models of growing subjects.
  
  
  METHODS
  Cone-beam computed tomography scans were taken before and after Class III malocclusion orthopedic treatment with miniplates. Three observers independently constructed 18 3D virtual surface models from cone-beam computed tomography scans of 3 patients. Separate 3D models were constructed for soft-tissue, cranial base, maxillary, and mandibular surfaces. The anterior cranial fossa was used to register the 3D models of before and after treatment (about 1 year of follow-up).
  
  
  RESULTS
  Three-dimensional overlays of superimposed models and 3D color-coded displacement maps allowed visual and quantitative assessment of growth and treatment changes. The range of interobserver errors for each anatomic region was 0.4 mm for the zygomatic process of maxilla, chin, condyles, posterior border of the rami, and lower border of the mandible, and 0.5 mm for the anterior maxilla soft-tissue upper lip.
  
  
  CONCLUSIONS
  Our results suggest that this method is a valid and reproducible assessment of treatment outcomes for growing subjects. This technique can be used to identify maxillary and mandibular positional changes and bone remodeling relative to the anterior cranial fossa.
authors: Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, NC 27599, USA. cevidanl@dentistry.unc.edu
authors: Lucia H C
authors: LH
authors: Cevidanes
authors: Gavin
authors: G
authors: Heymann
authors: Marie A
authors: MA
authors: Cornelis
authors: Hugo J
authors: HJ
authors: DeClerck
authors: J F Camilla
authors: JF
authors: Tulloch
mesh_terms: D001860:Bone Plates; D002648:Child; D002680:Chin / Q000254:growth & development; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D035262:Cranial Fossa, Anterior / Q000473:pathology; D005004:Ethmoid Bone / Q000473:pathology; D005145:Face; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008046:Lip / Q000254:growth & development; D008313:Malocclusion, Angle Class III / Q000628:therapy; D008334:Mandible / Q000254:growth & development; D008335:Mandibular Condyle / Q000254:growth & development; D008437:Maxilla / Q000254:growth & development; D008445:Maxillofacial Development / Q000502:physiology*; D015588:Observer Variation; D019291:Skull Base / Q000254:growth & development; D012984:Software; D016896:Treatment Outcome; D014584:User-Computer Interface; D015050:Zygoma / Q000254:growth & development