Interactive Osteotomy Simulation and Soft–Tissue Prediction

A system for interactive, 3–D, craniofacial surgery simulation is presented. It is used for simulation of bimaxillary osteotomies, physiological jaw movement, and for prediction of resulting soft–tissue changes. A 3–D, photorealistic model of the patient’s postoperative appearance is computed by the simulation process preoperatively. The system is based on the individual preoperative bone structure of a patient’s skull derived from a computer tomography scan and on the patient’s photorealistic, preoperative appearance obtained by a laser scanner. The multi–layer soft tissue is represented by springs. The model incorporates additional features such as skin turgor, gravity, and sliding bone contact. The prediction of soft–tissue deformation is computed using an optimization approach. Several optimization methods have been tested and compared with regard to robustness of the simulation result and to computational costs. Realistic osteotomy simulation can be performed interactively due to integrated collision detection.