The diagnostic value of computerized jaw tracking for arthrogenous temporomandibular disorders (TMDs)

The usefulness of jaw-tracking devices (axiography) in diagnosis of temporomandibular disorders (TMDs) remains unclear, because there are no generally accepted guidelines for the interpretation of such recordings. The objective of this study was to evaluate the diagnostic benefit of a computerized jaw tracking system for the evaluation of TMJ-related TMD. A total of 307 subjects (167 females and 140 males, mean age 35.9 ± 7.6) were selected from the cross-sectional epidemiological population-based study "Study of Health in Pomerania" (SHIP) for this evaluation. Data were collected with magnetic resonance imaging (MRI), 3D computerized axiography and clinical functional analysis. MRI examination resulted in the diagnosis no disc displacement (NDD) for 464 joints, partial disc displacement (PDD) for 107 joints, complete disc displacement with reduction (DDWR) for 5 joints and complete disc displacement without reduction (DDWOR) for 36 joints. Using MRI as the gold standard, electronic jaw tracking could separate disc displacements from sound joints with a sensitivity of 79% for right joints and 74% for left joints. Specificity of the axiography was 85% and 86% for the right and left side respectively. There was no significant correlation between clinical symptoms as pain upon palpation of the TMJ or self-reported pain of the TMJs and axiographic or MRI diagnosis. According disc displacements in the TMJ, electronic jaw tracking could achieve acceptable sensitivity and specifity levels when compared with MRI. For the diagnosis of painful TMD symptoms, however, axiography as well as MRI are of low value. Clinical examination methods should be employed. Keywords: temporomandibular disorders, temporomandibular joint dysfunction, internal derangement, computerized jaw tracking, magnetic resonance imaging, sensitivity, specificity