METHODS: 3D Shape Correspondence was used to localize and quantify condylar morphological differences of 29 female RDC/TMD group III (arthralgia, arthritis, arthrosis) patients (mean age= 38.7) as compared to a composite condylar model generated from 35 female asymptomatic subjects (mean age=23.7). 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 condylar models were normalized using rigid Procrustes alignment to an overall mean condylar model. Spearman rank tests were used to assess the local correlations of Visual Analog Scale pain intensity values and the time of pain onset to the parameterization of the shape of the condyles at every surface point.
RESULTS: The differences between the group mean surfaces were visualized with color-coded magnitude and difference vectors on the combined mean surface. The average condylar morphology in the RDC/TMD group III patients showed resorption of the antero-superior surface of the lateral pole and flattening of the articular surface, compared to the mean morphology in asymptomatic subjects. 3D shape correspondence color maps of both left and right condyles for the TMD subjects show areas in the anterior-superior surface of the condyle of strong positive correlation coefficients at every surface point with Pain Score and Pain Duration/Onset (r=0.6, surface red regions and p<0.05).
CONCLUSIONS: These preliminary studies indicate a statistically significant correlation exist between pain intensity and pain onset and specific locations in condylar morphologic variation in RDC/TMD III patients, as determined using 3D shape correspondence of surface models constructed from CBCT images.
Support: NIDCR DE017727, DE018962, DE005215, 2008 AADR Student Research Fellowship