Reconstruction of Posterior Mandibulectomy Defects in the Modern Era of Virtual Planning and Three-Dimensional Modeling

Background: Posterior mandibulectomy defects can be reconstructed using either soft tissue or vascularized bone. The authors hypothesize that advances in computer-aided design and manufacturing (CAD-CAM) have resulted in osteocutaneous free flaps now proving superior to soft-tissue flaps. Methods: The authors conducted a retrospective review of all free flap reconstructions of posterior mandibulectomy defects where the condyle was resected from 2005 to 2016. Results: Overall, 291 patients (mean age, 56.9 years; mean body mass index, 26.2 kg/m²) underwent posterior mandible reconstruction with 169 soft-tissue flaps and 122 osteocutaneous free flaps (90 free-hand versus 32 CAD-CAM). Forty patients (13.7 percent) required two free flaps to reconstruct the defect, most commonly a fibula osteocutaneous flap for the mandibulectomy defect and a soft-tissue flap for external coverage. Postoperatively, there were no differences in the incidence of trismus between soft-tissue versus vascularized bone flaps; however, malocclusion was most common in patients with soft-tissue flaps (p < 0.001). Patients with CAD-CAM bone reconstruction experienced significantly less malocclusion (p < 0.001), were more likely to progress to a regular diet (p = 0.001), and trended to having superior speech (p = 0.057) compared with the other cohorts. There were six total flap losses, with no difference between soft-tissue and bony flaps. Conclusions: Although reconstruction of posterior mandibulectomy defects should be based on the patient's comorbidities, surgeon comfort, and available resources, patients undergoing reconstruction of posterior mandibulectomy defects reconstructed with CAD-CAM-assisted fibulas experienced superior postoperative function compared with soft-tissue flaps or free-hand fibula flaps. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.