Temporomandibular Joint Involvement in Paediatric Patients Affected by Juvenile Idiopathic Arthritis

BACKGROUND: Juvenile idiopathic arthritis (JIA) is an autoimmune disease that can involve the temporomandibular joint (TMJ). OBJECTIVES: To investigate the association between clinical signs and symptoms of temporomandibular disorders (TMD) and TMJ inflammation, as detected by magnetic resonance imaging (MRI) in children and adolescents with JIA. METHODS: Monocentric cross-sectional observational study. Consecutive JIA patients underwent clinical dental examination following the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and performed MRI examination when the presence of signs and/or symptoms was detected. TMJ involvement was assessed using MRI parameters. Data were analysed with descriptive statistics, using parametric statistical tests for normally distributed data and non-parametric statistical tests for other variables. Associations between TMD signs/symptoms and MRI findings were investigated using appropriate statistical tests. Adjustment for multiple comparisons was performed using a false discovery rate approach. A p-value < 0.05 after correction was considered statistically significant. RESULTS: Seventy-six JIA patients were included. In unadjusted analyses, multiple associations emerged between clinical findings and MRI signs of TMJ involvement. After correction for multiple comparisons, TMJ sounds remained significantly associated with protrusion limitation, and mandibular deviation patterns were significantly associated with inflammatory MRI findings, particularly synovial thickening and bone marrow edema. Other associations did not retain statistical significance after adjustment and should be considered exploratory. CONCLUSIONS: Dental and TMD evaluations revealed correlations with MRI findings of TMJ involvement. Application of TMD screening at JIA onset might make it possible to detect TMJ-related early signs of arthritis in patients with JIA.