Interactive mesh cutting algorithm based on prism for virtual craniofacial osteotomy of orthognathic surgery

The diversity of osteotomy brings an obstacle to young experienceless surgeon to make preoperative plan. Computer-aided technique gives the birth of virtual osteotomy which assists surgeon with preoperative simulation of osteotomies in a visualized manner. However, the traditional cutting algorithm cannot meet the diverse demand of virtual osteotomies. This paper presents a prism cutting algorithm inspired by planar clipping. The proposed algorithm regards the cutting track of virtual surgical knife as the cutting intersection of a polygonal prism and a triangular mesh model. First, the geometrical property of cut sections of variant osteotomies is analyzed. Then, the spatial situations of triangle facet and prism constructed by interactive way are determined respectively. Finally, five kinds of craniofacial osteotomies are simulated. The results show that the proposed algorithms can handle effectively variant complex virtual osteotomies and provide further assistance with a preoperative guidance.