Are Signs of Degenerative Joint Disease Associated With Chin Deviation?

Degenerative joint changes commonly affect the temporomandibular joint (TMJ) and can result in chin deviation. However, the extent of degenerative TMJ changes and chin deviation has not been well-characterized. The present study sought to correlate degenerative TMJ changes with condylar volume, grayscale measures, and chin deviation.

The present cross-sectional study had enrolled women with skeletal Class III malocclusion. Cone-beam computed tomography scans were acquired preoperatively. For each condyle, degenerative TMJ signs were analyzed and the condylar volume and grayscale were measured. The predictor variable was the presence of degenerative TMJ signs, classified as categorical data: 0, if none; 1, only present in 1 joint; and 2, present in both joints. The primary outcome variable was a chin deviation of 3 mm or more. Other associated variables were grouped by age, cephalometric data, and 3-dimensional condylar measurements. Descriptive bivariate statistics were computed, and univariate and multiple logistic regression analyses were conducted to identify any associations between degenerative TMJ disease and chin deviation.

We included 85 patients, who were classified into 2 groups: less than 3 mm of chin deviation (n = 43) and 3 mm or more of chin deviation (n = 42). The presence of more than 10 degenerative TMJ signs was significantly associated with the presence of 3 mm or more of chin deviation (P < .001). In multiple regression models, the presence of subcortical sclerosis in 1 joint and in both joints (adjusted odds ratio [OR], 3.698; 95% confidence interval [CI], 1.051 to 13.012; adjusted OR, 5.001; 95% CI, 1.461-17.119, respectively) correlated significantly with the presence of 3 mm or more of chin deviation (P < .05). The volume difference between the 2 condyles was significantly greater in the group with more than 10 degenerative TMJ signs and 3 mm or more of chin deviation than in the group with 10 or fewer degenerative TMJ signs and less than 3 mm of chin deviation (P = .016 and P < .001, respectively).

In women with skeletal Class III malocclusion, the presence of more than 10 degenerative TMJ signs increased the prevalence of 3 mm or more of chin deviation. The presence of subcortical sclerosis in either 1 or both joints and volume differences between the 2 condyles were associated with greater chin deviation.