Augmented reality guided in reconstruction of mandibular defect with fibular flap: A cadaver study.

[BACKGROUND] Augmented reality (AR) navigation has been developed in recent years and can overcome some limitations of existing technologies. This study aimed to investigate a novel method of fibula free flap (FFF) osteotomy based on AR technology through a cadaver study.

[METHODS] One mandible, seven fibulas, and seven lower limb specimens underwent computed tomography (CT) examination. We used the professional software Proplan CMF 3.0 to design a defective mandible model and created fourteen virtual reconstruction plans using the fibulas and lower limb specimens. The AR-based intraoperative guidance software prototype was developed using the Unity Real-Time Development Platform, and virtual plans were transferred into this software prototype. We used AR-based surgical navigation to guide the FFF osteotomy and used these fibular segments to reconstruct the defective mandible model. After reconstruction, all segments were scanned by CT. Osteotomy accuracy was evaluated by measuring the length and angular deviation between the virtual plan and the final result. The reconstruction precision was reflected by the volume overlap rate and average surface distance between the planned and obtained reconstruction.

[RESULTS] The length difference, angular deviation, volume overlap rate and average surface distance of the in vitro group were 1.03±0.68 mm, 5.04±2.61°, 95.35±1.81%, and 1.02±0.27 mm, respectively. Those of the in vivo group were 1.18±0.84 mm, 5.45±1.47°, 95.31±2.09%, and 1.22±0.12 mm.

[CONCLUSIONS] Due to the ideal result of cadaver experiments, an AR-based FFF osteotomy guided system may become a novel approach to assist FFF osteotomy for the reconstruction of defective mandibles.