title: Temporomandibular joint involvement in children with juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To determine the rate of temporomandibular joint (TMJ) involvement and find factors associated with TMJ arthritis in a single-center cohort of patients with juvenile idiopathic arthritis (JIA).
  
  
  METHODS
  Retrospective analysis of all patients with JIA visiting the rheumatology clinic between January 1, 2005, and December 31, 2006. Followup information was included until August 2008. A diagnosis of TMJ arthritis was based on clinical rheumatological and/or radiological findings.
  
  
  RESULTS
  After a mean followup time for JIA of 4.6 years (range 0.08-14.17), 86/223 patients (38.6%) had developed TMJ arthritis. The rate of TMJ involvement differed significantly among JIA subtypes (p = 0.0016), with 61% in extended oligoarticular, 52% in polyarticular rheumatoid factor (RF)-negative, 50% in psoriatic, 36% in systemic, 33% in polyarticular RF-positive, 33% in persistent oligoarticular, 30% in unclassified JIA, and 11% in enthesitis-related arthritis. The rate of TMJ involvement in our cohort was statistically significantly lower for patients who were HLA-B27-positive (p = 0.0002). In a multivariate analysis, the association of the following factors was confirmed: JIA subtype (p = 0.0001), a higher erythrocyte sedimentation rate (ESR) at diagnosis (p = 0.0038), involvement of joints of the upper extremity (p = 0.011), the absence of HLA-B27 (p = 0.023), and younger age at onset of JIA (p = 0.050).
  
  
  CONCLUSIONS
  In our cohort of children with JIA, the overall rate of TMJ involvement was 38.6%. Patients with certain JIA subtypes, a higher ESR at disease onset, involvement of upper extremity joints, and younger age at diagnosis were more likely to develop TMJ arthritis. The presence of HLA-B27 seemed to be protective.
authors.affiliation: Zürich University Children's Hospital, Zürich, Switzerland.
authors.forename: Elvira
authors.initials: E
authors.lastname: Cannizzaro
authors.forename: Silke
authors.initials: S
authors.lastname: Schroeder
authors.forename: Lukas M
authors.initials: LM
authors.lastname: Müller
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Kellenberger
authors.forename: Rotraud K
authors.initials: RK
authors.lastname: Saurenmann
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000150:complications* / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D012189:Retrospective Studies; D013704:Temporomandibular Joint / Q000473:pathology*; D013705:Temporomandibular Joint Disorders / Q000209:etiology* / Q000473:pathology