An Anatomy-based Approach to Simulate the Temporomandibular Joint Movement

Besides enhancing the realism of the animation of virtual humans, the simulation of joints has become an important tool to help medical diagnosis and estimation of post-procedures results, thus simplifying and improving surgery planning. However, to be effective both in diagnosis and treatment planning, one needs to model the joints being analyzed according to the patient characteristics. This article proposes a model for the temporomandibular joint (TMJ) in such a way that the movement is modeled based on acquired real data. The proposed TMJ model can be tailored to simulate movement in diverse, specific situations obtained from real subjects. We describe a new topology for the TMJ, which allows dealing with the balanced motion between the two joints (left and right TMJ) and the mandible. The internal motion paths of both joints are obtained through inverse kinematics from the mandible external motion path, which can be acquired from real subjects. Validation is accomplished by means of comparison between the virtual articulation movement and acquired data – static and dynamic poses from a volunteer. In the proposed methodology, dynamic magnetic resonance images registration is used for comparing results from the animated model with real, acquired dynamic data.