Differentiating arthritic from myofascial pain in children with juvenile idiopathic arthritis: preliminary report.

Purpose: To differentiate between temporomandibular joint (TMJ) inflammation and myofascial pain (MPD) in children with juvenile idiopathic arthritis (JIA).

Patients And Methods: We performed a retrospective study of children with JIA evaluated at Boston Children's Hospital, Boston, Massachusetts. Patients, aged 16 years or younger at the time of diagnosis, were included if they had confirmed JIA with jaw signs or symptoms. Medical records and imaging studies were reviewed to document demographic, clinical, and radiographic findings. Patients with clinical evidence (joint pain/tenderness, asymmetry, limited motion) and radiographic evidence (condylar asymmetry, flattening, accentuated antegonial notch) of TMJ inflammation but without muscle pain were diagnosed with arthritis. Those with only muscle tenderness and/or limited jaw motion were diagnosed with MPD. Patients with TMJ inflammation and muscle pain/tenderness were considered to have co-existing arthritis and MPD. Outcome variables were the presence of TMJ arthritis and/or MPD. Descriptive statistics were computed.

Results: There were 61 patients (44 girls) with a mean age of 12.7 years (range, 3 to 16 years) who met the inclusion criteria. The most common clinical findings were limited mouth opening (n = 24), malocclusion/asymmetry (n = 23), and/or tenderness to palpation (n = 18). Twenty-one patients had multiple signs and symptoms. Panoramic radiographs showed condylar abnormalities in 32 patients. Overall, 21 patients (34.4%) were diagnosed with active TMJ arthritis, 21 (34.4%) with MPD, and 11 (18%) with both arthritis and MPD. Of the patients, 8 (13.1%) were in remission.

Conclusions: The results of this study indicate that in patients with JIA and jaw signs/symptoms, there is an overlap in diagnoses between arthritis and MPD. This has considerable implications for patient management.