THE CHARACTERISTICS OF STRESS AND DISPLACEMENT IN HUMAN TEMPOROMANDIBULAR JOINT DURING CENTRIC OCCLUSION / 解放军医学杂志

ABSTRACT

In order to study the stress distribution and displacement characternstic of the temporomandibular joint (TMJ) during centric occlusion, using the three dimensional nonlinear finite element model of normal human TMJ developed from in vivo with simulation of the contact relationship within TMJ, the stress and the maximum displacement of various structures in the TMJ were calculated and analyzed during centric occlusion. Furthermore, we separately accounted the mechanical properties of various structures in human TMJ and three dimensional muscle force vectors of their masticatory muscles measured and analyzed by use of the fusion of cranio jaw facial CT and MR image with the multiresolution method based on wavelet pyramid. The results showed that there were significant differences in the region and value of stress distribution on the surface of the disc, condyle and articular fossa during centric occlusion, in which the biggest stress was distributed in the condyle, the second in the articular fossa, and the smallest in the disc. During centric occlusion, the disc, condyle and articular fossa moved upperly, posteriorly and medially with the biggest displacement on the condyle, the secondary one on the disc and the smallest one on the fossa. It suggested that it is clinically feasible to systematically and rationally calculate and analyze the stress distribution and displacement character, and the results were satisfying