title: Temporomandibular joint structural derangement and general joint hypermobility.
abstract: OBJECTIVE
  To explore the relationship between general joint hypermobility (GJH) and displacement of the temporomandibular joint (TMJ) disc as evident from magnetic resonance imaging (MRI).
  
  
  METHODS
  Fifth finger extension, thumb apposition, elbow extension, knee extension, trunk flexion, and ankle dorsiflexion were measured in 66 young female patients with MRI-evident TMJ internal derangement (ID) and in 30 age-matched female controls. The Beighton score of each subject was measured quantitatively. The possible association between TMJ ID and mobility of a single joint or index of GJH, ie, the Beighton score, were assessed with one-way ANOVA with post-hoc Bonferroni and chi-square test, respectively. Correlations of the mobility of every measured joint were also explored.
  
  
  RESULTS
  Very few of the TMJ ID patients and control subjects were diagnosed with GJH according to the Beighton score. The Beighton score did not differentiate between subjects with and without TMJ ID. Subjects with TMJ ID, especially patients with MRI-evident disc displacement without reduction, seemed to have a stiffer trunk than controls, but this may not be of clinical relevance. The mobilities of paired joints were significantly correlated; however, the mobilities of different anatomical joints seemed to be independent.
  
  
  CONCLUSIONS
  Based on the Beighton score, GJH does not seem to be a reliable indicator of the presence of TMJ ID.
authors.affiliation: Department of Dentistry, Mackay Medicine, Nursing and Management College, Taipei, Taiwan.
authors.forename: Huey-Yuan
authors.initials: HY
authors.lastname: Wang
authors.forename: Tiffany Ting-Fang
authors.initials: TT
authors.lastname: Shih
authors.forename: Juo-Song
authors.initials: JS
authors.lastname: Wang
authors.forename: Yuh-Yuan
authors.initials: YY
authors.lastname: Shiau
authors.forename: Yunn-Jy
authors.initials: YJ
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000843:Ankle Joint / Q000503:physiopathology; D053587:Arthrometry, Articular; D016022:Case-Control Studies; D004551:Elbow Joint / Q000503:physiopathology; D005260:Female; D005384:Finger Joint / Q000503:physiopathology; D006801:Humans; D004204:Joint Dislocations / Q000150:complications*; D007593:Joint Instability / Q000150:complications*; D007719:Knee Joint / Q000503:physiopathology; D008279:Magnetic Resonance Imaging; D008335:Mandibular Condyle / Q000503:physiopathology; D016059:Range of Motion, Articular / Q000502:physiology; D013131:Spine / Q000503:physiopathology; D019224:Temporomandibular Joint Disc / Q000503:physiopathology*; D013705:Temporomandibular Joint Disorders / Q000150:complications*; D013933:Thumb / Q000503:physiopathology; D055815:Young Adult