Clinically established temporomandibular involvement in adults with juvenile idiopathic arthritis

Objective To study clinical variables defining temporomandibular function in adults with juvenile idiopathic arthritis (JIA) and healthy controls. Methods In this cross-sectional study the temporomandibular joint (TMJ) screening protocol, mandibular range of motion (MROM), and anterior maximum voluntary bite force (AMVBF) were compared between adults with JIA and healthy controls. Unadjusted and adjusted models with corrections for gender and disease duration were constructed for active maximum interincisal mouth opening (AMIO) and AMVBF. Results A total of 100 adults with JIA and 59 healthy adults were included in this study. In adults with JIA, 56.0% had clinically established TMJ involvement. AMIO was the MROM variable most reduced by TMJ involvement; AMIO was 8.8 mm (95%CI: -11.40 – -6.12; p<0.001) lower in adults with JIA with TMJ involvement compared to JIA without TMJ involvement. No differences of AMIO was found between healthy adults and adults with JIA without TMJ involvement (-2.52, 95%CI: - 5.13–0.10; p=0.06). Male gender was associated with a higher AMIO, and disease duration was associated with a decreased AMIO. Collinearity between the subtype pre-biological era and disease duration was found. AMVBF did not differ between adults with JIA and healthy adults. Conclusion The high prevalence of clinically established TMJ involvement in adults with JIA indicates the need for awareness of TMJ problems in adults with JIA. TMJ involvement negatively influenced AMIO and should therefore be part of the TMJ screening in adults with JIA. AMVBF seems to have less utility for TMJ screening in adult populations.