Effects of Biologics on Temporomandibular Joint Inflammation in Juvenile Idiopathic Arthritis.

Objective: This prospective study investigates the efficacy of biologics in combination with methotrexate (MTX) or leflunomide (LEF) on juvenile idiopathic arthritis (JIA)-related temporomandibular joint (TMJ) arthritis measured by magnetic resonance imaging (MRI)-based inflammation score and deformity score.

Methods: A prospective, single-center observational cohort study of 18 consecutive patients was performed between September 2018 and April 2023. Inclusion criteria were (1) diagnosis of JIA, (2) MRI-verified TMJ arthritis leading to treatment with tumor necrosis factor inhibitor (TNFi), (3) MRI at 6 months and 24 months after treatment initiation, and (4) clinical follow-up together with an MRI by a pediatric rheumatologist and an orthodontist.

Results: We included 18 patients (89% female). At the time of the first MRI, median age was 13.2 years (IQR 9.9-17.4), median disease duration was 7.8 years (IQR 3.4-11.1), and 4 received MTX or LEF. During the observation period, significant improvements were observed in TMJ movement pain ( = 0.01), morning stiffness ( = 0.004), opening capacity ( = 0.03), and maximal incisal opening ( = 0.006). The inflammation score decreased significantly from a median of 2 (IQR 1-3) at baseline to a median of 1 (IQR 0-2) at 24 months ( = 0.009). In 17 of 36 TMJs (47%), the deformity score improved or remained stable and no significant increase in the median score was observed.

Conclusion: This is the first prospective, observational study with evidence to support that the orofacial signs, symptoms, and MRI-derived inflammation score in TMJ arthritis can be reduced by treatment with TNFi.