Vascularized bone flaps versus nonvascularized bone grafts for mandibular reconstruction: An outcome analysis of primary bony union and endosseous implant success

Background. Functional restoration following resection or traumatic injury to the mandible depends on the reliability of the bony reconstruction to he al primarily and support endosseous implants. Although vascularized bone fl aps (VBF) and nonvascularized bone grafts (NVBG) are both widely used to re construct the mandible, indications for each remain ill-defined. The purpos e of this study was to compare bone graft/flap healing and success of impla nt placement in patients reconstructed with VBF versus NVBG. Methods. Over the past 10 years, 75 consecutive mandibular reconstructions were performed (26 free bone grafts, 49 vascularized bone flaps). Etiology of the defect, history of irradiation, bone defect size, number of operatio ns, graft/flap success, and dental implant success rates were determined an d compared. Bone graft/flap success was defined as complete bony union. Imp lant success was defined as complete osseointegration. Mean follow-up was 3 years. Results. Free flaps were used primarily for malignant disease (78%, 38/49). Bone grafts were used primarily for benign disease (88%, 23/26). History o f prior irradiation: 11%(3/26) NVBG versus 45% (22/49) VBF. Length of bony defect (mean): 8.1 cm NVBG versus 9.4 cm VBF. Successful bony union. any si ze defect: 69% (18/26) NVBG versus 96% (47/49) VBF (p <.0005); lateral defe cts only: 75% (15/20) NVBG versus 100% (17/17) VBF (p <.05). Number of oper ations to achieve bony union (mean), any size defect: 2.3 NVBG versus 1.1 V BF (p <.001); lateral defects only: 1.9 NVBG versus 1.0 VBF (p <.005). Twen ty-two patients (29%) had a total of 104 endosseous implants placed (NVBG: 8 patients, 33 implants; VBF: 14 patients, 71 implants). Immediate implants placed: 0/33 NVBG versus 54% (38/71) VBF. Overall implant success: 82% (27 /33) NVBG versus 99% (70/71) VBF (p <.0001). Implant success in VBF patient s with a history of RT: 100% (15/15). Conclusions. Despite the fact that patients reconstructed with VBFs were ol der, had larger defects, and were treated primarily for malignant disease a nd therefore had a higher incidence of irradiation to the affected mandible than in patients treated with NVBGs, the incidence of bony union was highe r. requiring fewer operations to achieve union, and the implant success rat e was significantly greater than for NVBG patients. Results were similar wh en considering lateral defects only. Based on these results, VBFs are indic ated in most cases of mandibular reconstruction; NVBGs are effective for sh ort bone defects (<5-6 cm), in nonirradiated tissue, and/or in patients det ermined to be too medically compromised to tolerate the additional operativ e time required for a free-flap reconstruction. (C) 1999 John Wiley & Sons, Inc.