Objective: This prospective study investigates the efficacy of biologics in combination with methotrexate or leflunomide 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 were performed between September 2018- 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 and 24 months after treatment initiation, 4) clinical follow-up contemporary with the MRI by a pediatric rheumatologist and an orthodontist.
Results: We included 18 patients (89% females). At time of first MRI median age was 13.2 years (IQR 11.3-16.9), median disease duration was 7.8 years (IQR 3.4-11.1) and 4 received MTX/leflunomide. During the observation period, significant improvements were observed in TMJ movement pain (p=0.01), morning stiffness (p=0.004), opening capacity (p=0.03) and maximal incisal opening (p=0.006). The inflammation score decreased significantly from median 2 (IQR 1-3) at baseline to median 1(IQR 0-2) at 24 months, p=0.009. In 17 out of 36 TMJs (48%), 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.