Condylar Morphology in Temporomandibular Disorder using 3D Shape Analysis

METHODS: 3D Shape Correspondence was used to localize and quantify condylar morphological differences of 20 patients (85% female, mean age = 36.9y) with RDC/TMD group III (arthralgia,arthritis,arthrosis) diagnosis to 40 asymptomatic subjects (78.1% female, mean age = 31.4y), consecutively imaged with CBCT from January 2006 to July 2007. 3D models of the right and left condyles of each subject were constructed from CBCT images and shape analysis performed using the publicly available SPHARM-PDM software. The right and left condyles were normalized using rigid Procrustes alignment to an overall mean condylar surface per group. The mean differences between groups were compared using the Hotelling T2 analysis with permutation-test derived p-values, corrected for False Discovery Rate.

RESULTS: The differences between the group mean surfaces were visualized with color-coded magnitude and difference vectors on the combined mean surface. On average, the condylar morphology of the TMD group was statistically significantly different from the asymptomatic group (p=0.05, average surface distance differences of 1.9 mm for the right condyles and 2.3 mm for the left condyles). The average condylar morphology in the TMD patients showed resorption of the anterior surface of the lateral pole and flattening of the articular surface, compared to the mean morphology in asymptomatic subjects.

CONCLUSIONS: The condylar morphology and condylar dimensions of the TMD patients were different, on average, from those of the asymptomatic subjects. The preliminary findings in this cross-sectional study will lead to future investigations to elucidate osteoarthritic changes in TMD and their role in the pathophysiology of TMD.

Supported by NIDCR DE017727 and DE005215