Accuracy and reproducibility of virtual cutting guides and 3D-navigation for osteotomies of the mandible and maxilla

Background We set out to determine the accuracy of 3D-navigated mandibular and maxillary osteotomies with the ultimate aim to integrate virtual cutting guides and 3D-navigation into ablative and reconstructive head and neck surgery. Methods Four surgeons (two attending, two clinical fellows) completed 224 unnavigated and 224 3D-navigated osteotomies on anatomical models according to preoperative 3D plans. The osteotomized bones were scanned and analyzed. Results Median distance from the virtual plan was 2.1 mm unnavigated (IQR 2.6 mm, >= 3 mm in 33%) and 1.2 mm 3D-navigated (IQR 1.1 mm, >= 3 mm in 6%) (P<0.0001); median pitch was 4.5 degrees unnavigated (IQR 7.1 degrees) and 3.5 degrees 3D-navigated (IQR 4.0 degrees) (P<0.0001); median roll was 7.4 degrees unnavigated (IQR 8.5 degrees) and 2.6 degrees 3D-navigated (IQR 3.8 degrees) (P<0.0001). Conclusion 3D-rendering enables osteotomy navigation. 3 mm is an appropriate planning distance. The next steps are translating virtual cutting guides to free bone flap reconstruction and clinical use.