Intraoperative cone-beam CT-guided osteotomy navigation in mandible and maxilla surgery

Surgical navigation systems based on preoperative imaging are now increasingly used for guidance of head and neck resection and reconstruction. The primary aim of this study was to quantify osteotomy cutting accuracy using an image-guidance system for intraoperative cone-beam computed tomography (CBCT) imaging and surgical saw navigation. To enable clinical translation of this CBCT-guided navigation system, a secondary aim of the study was to design and fabricate a patient reference tracker suitable for clinical use on a mobile mandible.

First, a preclinical cadaveric study was performed to quantify navigation accuracy with the use of clinically suitable patient reference trackers. Second, a proof-of-principle patient study was conducted to evaluate this technique under clinical conditions.

In both preclinical (5 cadavers) and clinical (5 patients) experiments, the mean cutting accuracy was less than 2 mm. In all preclinical specimens, bilateral mandibulectomies and bilateral maxillectomies were performed, for a total of 20 cut planes for analysis. The mean (standard deviation [SD]) values for distance, pitch, and roll were 1.4 mm (1.1 mm), 4.2° (3.5°), and 2.9° (2.5°) mm, respectively. Five mandibulectomies were performed on five patients, for a total of 10 cut planes for analysis. The mean (SD) values for distance, pitch, and roll were 1.7 mm (0.8 mm), 5.4° (1.5°), and 6.7° (4.6°) mm, respectively.

The overall performance in comparison to alternative approaches warrants further consideration. In terms of accuracy, the results presented here are comparable to recent systematic reviews assessing CAD-CAM cutting guides that cite accuracies of ~2 to 2.5 mm.

2 Laryngoscope, 130:1122-1127, 2020.