title: Heterotopic ossification of the temporomandibular joint in juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To describe the clinical, laboratory, pathologic, and radiographic imaging characteristics of a series of children with juvenile idiopathic arthritis (JIA) and radiographic imaging evidence of heterotopic ossification of their temporomandibular joint (TMJ).
  
  
  METHODS
  Children were identified through search of an administrative database of imaging results at Seattle Children's Hospital. Retrospective chart review was performed to collect data on each patient's clinical and laboratory characteristics, systemic therapies, timing and number of TMJ intraarticular corticosteroid injections (IAS), TMJ symptoms, and TMJ findings on physician examination. TMJ imaging studies for which heterotopic ossifications were reported were reviewed. Pathology specimens were reviewed for the 2 children who underwent synovial biopsy of their TMJ.
  
  
  RESULTS
  Twelve children were identified. The average duration between onset of JIA and detection of heterotopic ossification of TMJ on an imaging study was 36 months (range 19-94). Half the children had abnormal mouth-opening for age when the calcifications were first detected. In each case, the heterotopic ossification was first detected by computed tomography scan, and in 11 of the cases they were associated with synovial pannus formation as documented on an imaging study. Two children underwent synovial biopsy, which revealed reactive parosteal osteochondromatosis in one case and findings consistent with an intraarticular rheumatoid nodule in the other.
  
  
  CONCLUSIONS
  Heterotopic ossifications of the TMJ may be seen in children with JIA and are associated with particularly severe TMJ arthritis, joint destruction, and pannus formation. Pathology from these joints suggests that the heterotopic ossification may result from multiple pathological processes.
authors.affiliation: Seattle Children's Hospital and University of Washington, Seattle, WA 98105, USA. Sarah.Ringold@seattlechildrens.org
authors.forename: Sarah
authors.initials: S
authors.lastname: Ringold
authors.forename: Mahesh
authors.initials: M
authors.lastname: Thapa
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Shaw
authors.forename: Carol A
authors.initials: CA
authors.lastname: Wallace
mesh_terms: D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage / Q000627:therapeutic use; D001171:Arthritis, Juvenile / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007223:Infant; D007270:Injections, Intra-Articular; D008297:Male; D009999:Ossification, Heterotopic / Q000000981:diagnostic imaging / Q000473:pathology*; D012189:Retrospective Studies; D013583:Synovial Membrane / Q000473:pathology; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging / Q000473:pathology*; D014057:Tomography, X-Ray Computed
chemical_list: D000305:Adrenal Cortex Hormones