Diagnostic use of computerized axiography in TMJ disc displacements

Application of paraclinical methods for investigating the temporomandibular joint (TMJ) has been a subject of constant controversy due to the absence of universally-accepted criteria and lack of consensus regarding their usage. Compared with medical imaging, which provides a structural analysis of the TMJ, axiography involves the functional recording of condylar movements. The aim of the present study was to explore the diagnostic value of computerized axiography for TMJ disc displacements using MRI as the reference standard. The present study included 33 (66 TMJs) patients clinically diagnosed with TMJ disc displacements. On the same day, all patients underwent clinical examination and computerized axiography measurements using Cadiax Compact^® II before undergoing MRI (1.5 T) 1-7 days later. The characteristics of the diagnostic parameters, namely sensitivity, specificity, positive and negative predictive values, accuracy, Youden index and the 95% confidence intervals (CI), were all computed. Compared with MRI, computerized axiography yielded a sensitivity of 85.11%, specificity of 94.74%, positive predictive value of 97.56%, negative predictive value of 72% and a diagnostic accuracy of 87.88% for any disc displacements. This suggests that computerized axiography can confer high sensitivity, specificity and accuracy for the diagnosis of TMJ disc displacements. However, axiographic analysis has no diagnostic significance in TMJ function if not associated with clinical examination.