Three-dimensional evaluation of articular disc position and other temporomandibular joint morphology among Chinese patients with temporomandibular disorders: A retrospective MRI study

Abstract

Background The etiology and pathophysiology of temporomandibular disorders (TMDs), particularly the internal derangement of the joint, remain unclear. Accordingly, this study aimed to investigate the discal space changes, condylar position, and distance of disc displacement that occur in patients with temporomandibular disorder (TMD) and to explore joint space dimensions correlation to other factors such as age, sex, and distance of disc displacement. Methods A total of 130 patients (260 joints) were included in this cross-sectional study. The magnetic resonance imaging (MRI) of each patient was used to evaluate the temporomandibular joint (TMJ) discal space dimensions in the coronal and sagittal sections, and the distance of disc displacement. One-way ANOVA and Independent sample t-test were used for the normally distributed variables, and Kruskal-Wallis, Mann-Whitney u test were used for non-normally distributed variables. Bivariate correlation was conducted using spearman correlation coefficients to investigate the relation between age, disc position, and joint space dimensions. Results Among the sagittal spaces, the central joint space (CJS) was significantly larger on both sides (p < 0.001). When comparing joint spaces among sexes, the right side anterior joint space (AJS) was significantly greater in females (p = 0.006), while the left side medial and lateral joint spaces (MJS and LJS) were greater in males (p = 0.037 and 0.026, respectively). Discal space dimensions showed to be narrower in patients younger than 25 years, particularly for the central and medial discal spaces (p = < 0.001). The results of the bivariate analysis revealed a significant moderate to weak positive correlation between the age, AJS, CJS, and MJS in anterior disc displacement with reduction ADDWR (𝑟-2. = 0.408, 0.537, 0,287, respectively). Likewise, correlation between age and MJS showed weak correlation in anterior disc displacement without reduction ADDWoR (𝑟-2. = -0.253). Conclusion The central joint space is the largest among the other spaces. There are significant differences in joint space dimensions between sexes and age groups. Females have larger anterior joint spaces, whereas males present larger medial and lateral joint spaces. Additionally, younger individuals present narrower discal spaces, with age correlating moderately to weakly with joint space dimensions in cases of anterior disc displacement.