Preliminary study of virtual orthognathic surgical simulation and training.

[BACKGROUND AND OBJECTIVE] Virtual surgical simulation and training system offers a cost-effective and efficient alternative to traditional training and surgical planning. However, the algorithm for surgical simulation is sophisticated, and the requirement of computer software and hardware is high. The objective of this study was to explore the feasibility of tree-structure architectonic model in simplifying and realizing virtual orthognathic surgical simulation.

[METHODS] Four patients with skeletal malocclusions were enrolled in this study. Craniomaxillofacial computed tomography scan was obtained, and three-dimensional model was reconstructed using Simplant software. Maxillary Le Fort I osteotomy, bilateral sagittal split ramus osteotomy, vertical ramus osteotomy, and genioplasty were carried out on the three-dimensional model in advance. Tree-structure architectonic model was established in the sterolithography format. With stereoscopic glasses, using digital gloves, operators immersed in virtual environment and operated on "real" patients performing surgical simulation.

[RESULTS] Through establishing tree-structure architectonic model in advance, the complex algorithm for virtual osteotomy was simplified, and computational complexity was reduced. Three-dimensional model can be visualized from any viewing point. Operators were immersed in the virtual environment with a conspicuous sense of immersion. An obvious image and tactile feedback was perceived when touching and moving the bony segments. Virtual orthognathic surgical simulation and training were realized with real-time image and tactile perception feedback.

[CONCLUSIONS] Establishing tree-structure architectonic model in advance is an ideal alternative in implementing virtual orthognathic surgical simulation. Virtual surgical simulation and training were realized with a strong sense of immersion. Craniomaxillofacial three-dimensional virtual surgical simulation system can be used in orthognathic surgical planning, simulation, and operation training.