Computer-Assisted Preoperative Simulation and Augmented Reality for Plate Fixation Positioning in Genioplasty

a CT-based computer-assisted design and an intraoperative AR-guided system [4].The Paulus chin plate of 6 mm (Lorenz Plating System, Biomet Microfixation, Jacksonville, FL, USA) and the 3D scanner were used to scan the teeth (TRIOS3, 3Shape, Copenhagen, Denmark).A 320-row area detector CT scanner was used to scan the face (Aquilion ONE ViSION, Canon Medical System, Tochigi, Japan), which acquired CT scans (0.35 mm/pixel size and 0.5 mm/pixel slice thickness).Mimics software was used in conjunction with a 3D scanner and CT data to recreate 3D surfaces (version 24.0, Materialise, Leuven, Belgium).A genioplasty simulation was performed using the 3D mandible model, according to the surgical plan.Mimics software was used to calculate bone movement and screw positions (Fig. 1).In the actual AR surgery (Fig. 2, Supplementary video), a 3840 × 2160 pixels image resolution 4 K camera was used (Next Vision, Yoshida, Tokyo, Japan).Prior to distortion removal, the camera was calibrated to obtain the intrinsic matrix K and lens distortion coefficients.C + + was used to implement all of the core algorithms [4].The medical ethics committee of the Graduate School of Medicine, affiliated to the University of Tokyo in Japan, provided due approval for this study.During the real operation (Fig. 3 and4), the positioning of plate in genioplasty was done based on this preoperative planning and AR.It is anticipated that this simulation method will help surgeons in planning and performing operative procedures more precisely in orthognathic surgery.With the assistance of see-through AR guidance, our intraoperative markerless video system is capable of addressing issues pertaining to initial alignment and maintaining the accuracy of registration in real-time, eliminating the need for manual adjustment.Our work is presumably the first to achieve marker-less video see-through AR for genioplasty.This method is anticipated to be incorporated increasingly into