Robot-Assisted Mandibular Angle Osteotomy Using Electromagnetic Navigation

Background: To explore the potential of electromagnetic (EM) navigation technology in the field of robot assisted surgery, we set up a maxillofacial surgical robotic system (MSRS) guided by an EM navigation tool. Mandibular angle osteotomy was used to analyze the feasibility in confined surgical areas.Methods: Model and animal experiments were implemented to validate the system precision. Before the experiment, a customized dental splint was made and then fixed with a standard navigation part. An accurate 3D surgical plan was designed based on the preoperative CT scan. During the experiment, the splint was rigidly mounted on teeth for navigation registration, so the robot could position a specially designed template to guide the accurate osteotomy according to the preoperative plan. For the model experiment, a Coordinate Measuring Machine was used to measure the template's position and angle. For the animal experiment, surgeons completed the surgery by moving a saw along the template, while a postoperative CT scan was carried out to calculate the precision.Results: All procedures were successfully completed, with no complications in any of the experimental animals. In the model experiment, the accuracy of the navigation position and angle was 0.44 +/- 0.19 mm and 3.5 degrees +/- 2.1 degrees, respectively. In the animal experiment, the lateral osteotomy line error was 0.83 +/- 0.62 mm, the interior error was 1.06 +/- 1.03 mm, and the angle between the actual cutting plane and preoperative planning plane was 5.9 degrees +/- 4.7 degrees.Conclusions: Robot-assisted surgery with EM navigation resulted feasible in the real operating environment. Moreover, this system's precision could meet clinical needs, while the proposed procedure was safe and easy on animals. Consequently, this approach has the potential to be applied to clinical craniomaxillofacial practice in the near future.