Mathematical modeling and numerical simulation in maxillo-facial virtual surgery (VISU).

Computer-based surgery simulation is a rapidly emerging and increasingly important area of research that combines a number of disciplines for the common purpose of improving healthcare. The objective of this paper is to provide a virtual surgery (VISU) tool for accurately planning the aesthetic impact of hard and soft tissue movements in dento-skeletal malocclusions. The approach proposed here allows direct interaction with a completely three-dimensional (3-D) computed tomography (CT) model of a solid, highly detailed structure of the head to obtain a realistic prediction of soft tissue behavior. We studied 25 patients who had facial malformations pre- and postoperatively with 3-D hard and soft tissue CT studies, and maxillary or mandibular osteotomies were simulated. The postoperative 3-D CT and facial outcomes were compared with the simulations. In 80% of the cases studied, the simulation-predicted changes, when compared with the clinical outcomes, were within the tolerance level (2 mm) established by maxillo-facial surgeons.