title: Three-dimensional soft tissue analysis for the evaluation of facial asymmetry in normal occlusion individuals.
abstract: OBJECTIVE
  To identify the right and left difference of the facial soft tissue landmarks three-dimensionally from the subjects of normal occlusion individuals.
  
  
  METHODS
  Cone-beam computed tomography (CT) scans were obtained in 48 normal occlusion adults (24 men, 24 women), and reconstructed into 3-dimensional (3D) models by using a 3D image soft ware. 3D position of 27 soft tissue landmarks, 9 midline and 9 pairs of bilateral landmarks, were identified in 3D coordination system, and their right and left differences were calculated and analyzed.
  
  
  RESULTS
  The right and left difference values derived from the study ranged from 0.6 to 4.6 mm indicating a high variability according to the landmarks. In general, the values showed a tendency to increase according to the lower and lateral positioning of the landmarks in the face. Overall differences were determined not only by transverse differences but also by sagittal and vertical differences, indicating that 3D evaluation would be essential in the facial soft tissue analysis.
  
  
  CONCLUSIONS
  Means and standard deviations of the right and left difference of facial soft tissue landmarks derived from this study can be used as the diagnostic standard values for the evaluation of facial asymmetry.
authors.affiliation: Department of Orthodontics, 2nd Stage of Brain Korea 21, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Korea.
authors.forename: Hyeon-Shik
authors.initials: HS
authors.lastname: Hwang
authors.forename: Donghui
authors.initials: D
authors.lastname: Yuan
authors.forename: Kweon-Heui
authors.initials: KH
authors.lastname: Jeong
authors.forename: Gi-Soo
authors.initials: GS
authors.lastname: Uhm
authors.forename: Jin-Hyoung
authors.initials: JH
authors.lastname: Cho
authors.forename: Sook-Ja
authors.initials: SJ
authors.lastname: Yoon
keywords: Cone-beam CT; Facial asymmetry; Soft tissue; Three-dimensional