title: Normal range of facial asymmetry in spherical coordinates: a CBCT study.
abstract: OBJECTIVE
  This study aimed to measure the bilateral differences of facial lines in spherical coordinates from faces within a normal range of asymmetry utilizing cone-beam computed tomography (CBCT).
  
  
  METHODS
  CBCT scans from 22 females with normal symmetric-looking faces (mean age 24 years and 8 months) were selected for the study. The average menton deviation was 1.01±0.66 mm. The spherical coordinates, length, and midsagittal and coronal inclination angles of the ramal and mandibular lines were calculated from CBCT. The bilateral differences in the facial lines were determined.
  
  
  RESULTS
  All of the study subjects had minimal bilateral differences of facial lines. The normal range of facial asymmetry of the ramal and mandibular lines was obtained in spherical coordinates.
  
  
  CONCLUSIONS
  The normal range of facial asymmetry in the spherical coordinate system in this study should be useful as a reference for diagnosing facial asymmetry.
authors.affiliation: Department of Oral and Maxillofacial Radiology, School of Dentistry, Dental Science Research Institute, Chonnam National University, Gwangju, Korea.
authors.forename: Suk-Ja
authors.initials: SJ
authors.lastname: Yoon
authors.forename: Rui-Feng
authors.initials: RF
authors.lastname: Wang
authors.forename: Hee Ja
authors.initials: HJ
authors.lastname: Na
authors.forename: Juan Martin
authors.initials: JM
authors.lastname: Palomo
keywords: Cone-Beam Computed Tomography; Facial Asymmetry; Imaging, Three-Dimensional