title: Three-dimensional quantification of mandibular asymmetry through cone-beam computerized tomography.
abstract: OBJECTIVE
  The aim of this study was to determine if 3-dimensional (3D) shape analysis precisely diagnoses right and left differences in asymmetry patients.
  
  
  METHODS
  Cone-beam computerized tomography (CT) data were acquired before treatment from 20 patients with mandibular asymmetry. 3D shape analysis was used to localize and quantify the extent of virtually simulated asymmetry. Two approaches were used: 1) mirroring on the midsagittal plane determined from landmarks; and 2) mirroring on an arbitrary plane and then registering on the cranial base of the original image. The validation presented in this study used simulated data and was applied to 3 clinical cases.
  
  
  RESULTS
  For mirroring on the midsagittal plane, there was a >99% probability that the difference between measured and simulated asymmetry was <0.5 mm. For mirroring with cranial base registration, there was a >84% probability of differences <0.5 mm.
  
  
  CONCLUSIONS
  Mandibular asymmetry can be precisely quantified with both mirroring methods. Cranial base registration has the potential to be used for patients with trauma situations or when key landmarks are unreliable or absent.
authors.affiliation: Department of Orthodontics, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina 27599, USA. cevidanl@dentistry.unc.edu
authors.forename: Lucia H S
authors.initials: LH
authors.lastname: Cevidanes
authors.forename: Abeer
authors.initials: A
authors.lastname: Alhadidi
authors.forename: Beatriz
authors.initials: B
authors.lastname: Paniagua
authors.forename: Martin
authors.initials: M
authors.lastname: Styner
authors.forename: John
authors.initials: J
authors.lastname: Ludlow
authors.forename: Andre
authors.initials: A
authors.lastname: Mol
authors.forename: Timothy
authors.initials: T
authors.lastname: Turvey
authors.forename: William R
authors.initials: WR
authors.lastname: Proffit
authors.forename: Paul Emile
authors.initials: PE
authors.lastname: Rossouw
mesh_terms: D000293:Adolescent; D000328:Adult; D002508:Cephalometry / Q000295:instrumentation* / Q000379:methods; D002648:Child; D003198:Computer Simulation; D054893:Cone-Beam Computed Tomography; D005146:Facial Asymmetry / Q000000981:diagnostic imaging*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D008334:Mandible / Q000002:abnormalities / Q000000981:diagnostic imaging*; D008336:Mandibular Diseases / Q000000981:diagnostic imaging; D008953:Models, Anatomic; D056948:Orthognathic Surgical Procedures / Q000295:instrumentation; D019291:Skull Base / Q000000981:diagnostic imaging; D055815:Young Adult