Temporomandibular Joint Involvement in Juvenile Idiopathic Arthritis: Diagnostic Validity of DC/TMD Clinical Examination

Objectives: to assess the validity of the 3.B Diagnostic Criteria for Temporomandibular Disorders (DC/TMD 3.B) for the identification of temporomandibular joint (TMJ) involvement in Juvenile Idiopathic Arthritis (JIA) patients, using magnetic resonance imaging (MRI) as gold standard. To establish the association between clinical findings and severity of TMJ damage.
Methods: 50 consecutive JIA-patients, (9-16 years) were recruited. TMJ involvement was diagnosed with DC/TMD expanded taxonomy. Each joint (100 TMJs) was assessed by MRI performed closely (≤1 month) to the date of the visit. The severity of osseous deformity was scored in 4 grades. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of DC/TMD respect to MRI, univariate and multivariate logistic regression model with Odds Ratio were calculated.
Results: DC/TMD 3.B showed a sensitivity of 0.15 and a specificity of 0.92 in the identification of TMJ involvement (P=0.350). PPV was 0.85 and NPV was 0.28. Chin deviation and TMJ crepitus were associated to the worsening of TMJ involvement (P=0.006; P=0.034). Jaw opening reduction (OR=3.91, 95%CI 1.07-14.3, P=0.039) and chin deviation (OR=13.7, 95%CI 1.7-110.2, P=0.014) were associated with the presence of TMJ damage. We suggest diagnostic certainty graded as possible when pain was reported or recorded, probable when crepitus or reduced mouth opening or chin deviation was present, and definite with positive findings assessed by imaging.
Conclusions: DC/TMD present a low sensitivity to diagnose TMJ involvement in JIA-patients. Chin deviation, jaw opening reduction and TMJ crepitus are associated with TMJ damage. We suggest diagnostic criteria graded as possible, probable, and definite for TMJ involvement in JIA patients.