Electromagnetic Navigation in Mandibular Reconstruction Using Autologous Grafts: A Color-Coded Assistance for Precise...

Background and Objectives: Virtual surgical planning (VSP) is well established in mandibular reconstruction. However, it is difficult to position bone segments precisely in the operating room due to a lack of visual control and deviating intraoperative conditions. Navigation can help to transfer surgical plans more precisely. We present a color-coded navigation based on electromagnetic tracking that provides simplified 3-dimensional (3D) visualization and real-time feedback to assist with precise bone segment positioning. The aim of this study is to evaluate our approach in model surgeries using 3D-printed bones. Methods: We developed software for landmark-based registration and color-coded navigation. Prior to model surgeries, VSP was performed on 11 cases involving hemimandibular defects using in-house software. Osteosynthesis plates were prepared, and bone phantoms and cutting guides were 3D-printed. Mandibular reconstructions were then performed in a laboratory setting using our navigation software. To evaluate applicability and accuracy of our navigation, we compared anatomical and artificial landmarks on the graft via postoperative cone beam computed tomography. Results: Navigated mandibular reconstructions were precise compared to VSP, with measured spatial differences of 2.16 ± 1.1 mm at artificial landmarks, 2.95 ± 1.59 mm at the condyle, 2.37 ± 1.4 mm at the jaw angle, and 1.13 ± 0.75 mm at the junction between graft and residual mandible. No substantial differences were found between navigation measurements and cone beam computed tomography. Conclusions: Color-coded navigation with simplified 3D visualization of bone segments yielded promising results in model surgery. It has great potential to assist with precise bone segment positioning in mandibular reconstruction.