Evaluation of morphometric and volumetric measurements of temporomandibular joint structures on patients with disc displacement

Introduction: To evaluate the morphometric and volumetric measurements of the temporomandibular joint (TMJ) structures, of healthy, anterior disc displacement with reduction (ADDWR) and anterior disc displacement without reduction (ADDWoR) joints using magnetic resonance imaging (MRI). Material and Methods: Fifty-two TMJs of 38 patients with TMJ disorders and 26 TMJs of 13 healthy patients were evaluated on MRI images. The disc length and volume, the condylar height, width and volume, and the height and inclination of the articular eminence were measured on MRI. A one-way analysis of variance was used to establish the differences between the values with regard to the ADDWR, ADDWoR, and control groups. The differences in the disc volumes of each group with respect to open and closed mouth position statuses were evaluated using the Bonferroni test. Results: The articular disc mean volume was larger in the control group than the other two groups for both the closed and open mouth positions (P < 0.05). There were statistically significant differences between the control group and the other two groups in terms of the condylar width and disc length (P = 0.00 and P = 0.001, respectively). The mean articular eminence inclination was the lowest in the ADDWoR group and the highest in the control group (P = 0.02). Discussion and Conclusion: Measurements of the disc volume, disc length, condylar width, and articular eminence inclination are associated with disc displacement (DD). Degenerative changes that may cause morphometric and volumetric changes in TMJ structures may be a marker of TMJ DD.