Predicting the Number of Fibular Segments to Reconstruct Mandibular Defects.

OBJECTIVES: Several classification schemes have been proposed to categorize mandibular defects following surgical resection; however, there is a paucity of data to guide an optimal reconstruction. This study examines the feasibility of using a geometric algorithm to simplify and determine the optimal reconstruction for a given mandibular defect. This algorithm is then applied to three different mandible defect classification schemes to correlate the defect type and number of bony segments required for reconstruction. METHODS: Computed tomography (CT) scans of 48 mandibles were decomposed into curvilinear representations and analyzed using the Ramer-Douglas-Peucker algorithm. In total, 720 mandibular defects were created and subsequently analyzed utilizing three commonly referenced classification systems. For each defect, the number of bony segments required to reconstruct each defect was computed. RESULTS: A wide variance in the number of segments needed for optimal reconstruction was observed across existing classifications. A six-segment total mandible reconstruction best reconstituted mandibular form in all 48 mandibles. CONCLUSION: Defect classification schemes are not adaptable to predicting the number of fibula segments required for a given defect. Additionally, cephalometric templates may not be applicable in all clinical settings. The Ramer-Douglas-Peucker algorithm is well suited for providing case-specific predictions of reconstruction plans in a reproducible manner. LEVEL OF EVIDENCE: IV Laryngoscope, 130:E619-E624, 2020.

Mandibular reconstructions using computer-aided design/computer-aided manufacturing: A systematic review of a defect-based reconstructive algorithm.

Modern planning techniques, including computer-aided design/computer-aided manufacturing (CAD-CAM) can be used to plan reconstructive surgery, optimising aesthetic outcomes and functional rehabilitation. However, although many such applications are available, no systematic protocol yet describes the entire reconstructive procedure, which must include virtual planning, custom manufacture, and a reconstructive algorithm. We reviewed current practices in this novel field, analysed case series described in the literature, and developed a new, defect-based reconstructive algorithm. We also evaluated methods of mandibular reconstruction featuring virtual planning, the use of surgical guides, and laser printing of custom titanium bony plates to support composite free flaps, and evaluated their utility.