Simulation of jaw-movements for the musculoskeletal diagnoses.

Simulations of static and dynamic aspects of the functionality of the human body are getting more important as the complexity of operations increases. The preoperative planning of maxillofacial operations like the repositioning of the jaw is an example for such operation. Here, but also in other medical fields, simulation can help to estimate the results of a procedure or can facilitate the diagnosis through a better view of the anatomy and pathology of the patient. A virtual view on the pathology and the possibility of simulating the postoperative results simplifies and improves the preoperative planning. The goal of our research is the development of a graphical simulation of the human mastication system to give the surgeon an impression on the inner anatomy of his patient. This simulation allows him to predict the aesthetic and functional outcome of his operation. The main focus of this paper is the introduction of a kinematic model of the temporomandibular joint. This kinematic model describes the geometrical and analytical movement of the jaw by specially defined axes. It is the basis for an animated simulation of the mandible movement. Through integration of the muscles and muscle forces, we come to a realistic dynamic simulation of the whole mastication system.