title: 3D analysis of facial asymmetry in subjects with juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To investigate and compare facial asymmetry in subjects with JIA with unilateral, bilateral or no TM joint (TMJ) involvement.
  
  
  METHODS
  Eighty-one subjects with JIA: 22 with unilateral TMJ involvement (Group 1), 15 with bilateral TMJ involvement (Group 2) and 44 with no TMJ involvement (Group 3). Panoramic X-rays and three-dimensional (3D) photographs (surface scans) were obtained for all subjects. Panoramic X-rays were rated for severity of TMJ involvement. For each individual, a spatially detailed facial asymmetry map was created from the 3D photograph. Mean and variability of asymmetry were calculated for each of the three groups and compared.
  
  
  RESULTS
  Distinct patterns of asymmetry were found in Groups 1 and 2. With mean asymmetry values up to 3.5 mm, Group 1 exhibited a significantly greater amount of asymmetry in a broad band along the lower jaw extending from the region of the condyle to the chin than Group 2. The mean facial asymmetry (1 S.D.) for each JIA group was 2.3 (0.9), 2.0 (0.7), 1.7 (0.5) mm for Groups 1, 2 and 3, respectively.
  
  
  CONCLUSIONS
  JIA subjects with TMJ involvement displayed patterns of facial asymmetry consistent with the destruction of the condylar growth centre, leading to mandibular asymmetry with displacement of the bony chin. Facial asymmetry quantification was found to be an effective method for assessing both the amount and the localization and spatial extent of asymmetry in all 3Ds.
authors.affiliation: Department of Pediatric Dentistry and Clinical Genetics, School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Nørre Allé 20, DK-2200 Copenhagen N, Denmark.
authors.forename: Sune
authors.initials: S
authors.lastname: Demant
authors.forename: Nuno V
authors.initials: NV
authors.lastname: Hermann
authors.forename: Tron A
authors.initials: TA
authors.lastname: Darvann
authors.forename: Marek
authors.initials: M
authors.lastname: Zak
authors.forename: Helena
authors.initials: H
authors.lastname: Schatz
authors.forename: Per
authors.initials: P
authors.lastname: Larsen
authors.forename: Sven
authors.initials: S
authors.lastname: Kreiborg
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000150:complications*; D002648:Child; D002675:Child, Preschool; D005146:Facial Asymmetry / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D010780:Photogrammetry; D011859:Radiography; D012189:Retrospective Studies; D055815:Young Adult