LAUSR

The quality of oral and maxillofacial surgery (OMS) significantly depends on the accuracy of surgical navigation. In this article, a vision-based markerless surgical navigation system is developed to overcome the shortcomings in the currently available technologies. Registration methods both for patient and surgical instrument tracking are improved to increase the navigation performance. For patient-image registration, we propose an efficient texture-less pose estimation method using only shape information. An innovative strategy is developed to effectively reject the outliers and improve the pose accuracy, which is the first attempt at introducing geometric matching information to guide PnP calculation. For surgical instrument tracking, a position-sensing marker is used to achieve robust and convenient instrument localization with high accuracy. Experiments were conducted on the 3-D-printed maxilla and mandible models to evaluate the navigation performance. Evaluation results validate the effectiveness of the proposed pose estimation method in improving the pose accuracy for texture-less teeth. Besides, it is revealed that the position-sensing marker can be localized with high accuracy even under nonideal visibility conditions, which expands the motion range of the instrument and decreases the size of the tool. The entire system has a sufficiently small target registration error (TRE). These experimental results have verified that the proposed surgical navigation system can provide practical guidance for OMS with satisfactory accuracy.