A35: Differential Benefit of Temporomandibular Joint Steroid Injections by Juvenile Idiopathic Arthritis Subtype

Background/Purpose: 20–70% of juvenile idiopathic arthritis (JIA) patients have radiographic involvement of temporomandibular joints (TMJs), often reflective of cartilage loss and erosive bony changes. Intra‐articular steroid (IAS) injections have been shown by magnetic resonance (MR) imaging to reduce TMJ inflammation; however, it is less clear that this therapy provides longer term benefit in terms of preventing or retarding structural changes. Herein, we review the outcomes of our JIA patients treated with IAS for TMJ synovitis. Methods: Records of JIA patients treated with IAS for TMJ synovitis between January of 2003 and March of 2013 were reviewed. Determinations of symptomatic relief and duration of relief were made from both subjective and objective portions of notes generated at clinic visits subsequent to an initial IAS procedure. Determinations of radiographic progression were based on structural changes occurring between 1st and 2nd IAS procedures. The IAS used was triamcinolone hexacetonide in doses of 5–20 mg per joint. Results: 63 patients received IAS at least once for TMJ synovitis, almost all for bilateral disease activity by MRI. Within this cohort, 55% of patients had received g1 injection per TMJ (mean of 2.75 for enthesitis‐related arthritis (ERA) patients vs. 1.95 for other combined JIA subtypes, p = 0.03). For 25% of patients, the TMJ was their first synovitic joint (58 % of ERA vs. 7.5% of other JIA subtypes, p < 0.001). ERA patients were older at at the time of TMJ diagnosis than the other JIA subtypes (mean age 14.0 vs. 11.5 years respectively, p = 0.003) and more likely to be symptomatic at the TMJ(s) than the other JIA subtypes (79% vs. 48% respectively, p = 0.018). Symptomatic ERA patients had a shorter mean duration of pain relief than the other symptomatic JIA subtypes (107 vs. 363 days respectively, p = 0.001). Second MR studies indicated progressive structural damage in all (32/32) patients re‐imaged at intervals of 6N36 months following their initial study. More acute TMJ symptoms and heightened concern for progression in the ERA patients resulted in a shorter mean inter‐injection interval of 10.9 vs. 19.9 months in the other JIA subtypes (p = 0.004). Conclusion: Of the JIA patients in clinic who have received IAS for TMJ synovitis, those with ERA benefitted the least in terms of pain relief duration and slowing of structural damage. In light of the higher frequency of IAS and the shorter duration of symptomatic relief in ERA patients, it is possible that TMJ synovitis is more aggressive in this subtype, or that a symptom‐driven increase in the frequency of IAS therapy has contributed to the rate and extent of structural damage. IAS therapy, in our experience, has not prevented the progression of TMJ damage in any JIA variant.