Mandibular Condyle Bone Mineral Density to Diagnose Temporomandibular Joint Disorder

Objectives: Research Diagnositc Criteria (RDC) have been suggested to diagnose temporomandibular joint disorder (TMJD) using patients’ images in clinical settings. On the other hand, it has been observed that active bone remodeling involves in TMJD associated osteoarthritis of mandibular condyle, which alters bone mineral density (BMD) distribution. Thus, the objective of this study was to examine whether the RDC based diagnosis is associated with bone mineral density distribution of human mandibular condyles.
Methods: Institutional Review Board approval was obtained for retrospective analysis of cone beam computerized tomography (CBCT) images taken from 29 male and 40 female patients. Bilateral mandibular condyles in the 3D CBCT images were digitally dissected by 7 mm from top surface down to the occlusal plane. Total voxels of condyle were counted to compute its volume. A histogram of gray values (CT attenuation values proportional to BMD) was obtained to measure mean, standard deviation (SD), 5^th percentile low and high values of BMD. Disected images of each left and right condyle was examined individually using RDC. Individual condyles were scored by counting frequency of presents in RDC. Paired t-tests were used to compare right and left parameters. Significance was p<0.05.
Results: The left mandibular condyle had significantly higher frequency of presents in RDC, volume, mean, SD, Low and High gray values than the right mandibular condyle (p<0.007).
Conclusions: The differences of volume and BMD parameters between right and left mandibular condyle in CBCT images were parallel with the diagnostic results based on the RDC. The current finding suggests that the CBCT based measures can provide additional information to diagnose the TMJD.