Accuracy and outcomes of virtual surgical planning and 3D-printed guides for osseous free flap reconstruction of mandibular osteoradionecrosis

Objectives: Virtual surgical planning, 3D-printed osteotomy guides and preoperatively-bent or custom-milled mandibular reconstruction plate (VSP/3Dprinted-guide/plate) have been shown to ease intraoperative deci-sion making and reduce operative time. Few studies have examined outcomes of VSP/3Dprinted-guide/plate specifically for mandibular osteoradionecrosis (mORN) cases, which pose unique challenges. We aimed to examine reconstruction accuracy, functional outcomes, and postoperative complications following osseous-free -flap reconstruction with VSP/3Dprinted-guide/plate for mORN.Materials and methods: Single academic medical center retrospective case series of ORN-related osseous-free-flap mandibular reconstructions with VSP/3Dprinted-guide/plate between January 2015 and March 2021. Most cases were performed by the same two-surgeon team. Outcomes include reconstruction accuracy (assessed by 3D -over-lay computer models with cephalometric and donor-bone segment length measurements), complications and function.Results: Twenty-six cases were identified with a mean follow-up of 85 weeks. Most patients were male (69 %); mean age was 64 years. 3D-model-overlay demonstrated minimal deviation between planned and actual reconstruction among 18 evaluable cases: intercondylar distance = 1.46 mm (SD 2.4); intergonial distance = 1.82 mm (SD 2.0); anterior-posterior distance = 2.14 mm (SD 1.9); gonial angle = 3.33 degrees (SD 2.4). Mean change donor-bone segment length inferiorly 4.39 mm (SD 4.3) and superiorly 3.43 mm (SD 4.0). Complications: returned to operating room (N = 2), minor primary/neck site infection/dehiscence (N = 11). Function improved postoperatively: 20/21 (95 %) cases with preoperative pain, resolved; 13/20 (65 %) with preoperative trismus, improved; 21/24 (87 %) with preoperative malocclusion/jaw malignment, improved.Conclusions: This is the largest series of VSP/3Dprinted-guide/plate surgery for mORN to date. Mandibular reconstruction for ORN is aided by VSP/3Dprinted-guide/plate with accurate results, acceptable complications, and improved function.