Temporomandibular joint arthritis in juvenile idiopathic arthritis: prevalence, clinical and radiological signs, and relation to dentofacial morphology.

OBJECTIVE: To perform a prospective, comprehensive, clinical, and radiological evaluation of temporomandibular joint (TMJ) involvement and its influence on craniofacial growth, in a cohort of patients with juvenile idiopathic arthritis (JIA), representing all JIA subtypes.
METHODS: Clinical rheumatologic and orthodontic evaluations were performed in 100 patients with JIA [12 systemic arthritis, 24 rheumatoid factor (RF)-negative polyarthritis, 1 RF-positive polyarthritis, 39 oligoarthritis, 22 enthesitis-related arthritis, 2 psoriatic arthritis]. An orthopantomogram and lateral cephalogram were performed in 46 patients. The prevalence of TMJ arthritis was studied in relation to JIA subtype and disease characteristics; cephalometric measurements were compared to those from age- and sex-matched healthy controls.
RESULTS: Whereas 55% of patients with JIA had at least one symptom/sign of TMJ arthritis, 78% of the radiographed group exhibited condylar lesions. The presence of condylar damage was not related to clinical orthodontic findings or to JIA subtype, disease activity, severity, or duration. Patients with JIA exhibited larger mandibular plane and A-nasion-B angles, larger total anterior facial height, smaller interincisal and sella-nasion-B angles, and shorter mandibular ramus lengths than their age- and sex-matched controls. Craniofacial alterations were clearly related to the presence of condylar damage, even when present at a minimal degree.
CONCLUSION: Our data show that TMJ condylar damage occurs very frequently in JIA, and irrespective of JIA subtype; condylar lesions can present early, progress insidiously, and -- even at a minimal degree -- can severely alter the craniofacial profile. We propose that the followup of patients with JIA should include early and regular evaluation by an orthodontist, supplemented with radiographic TMJ imaging.