Autogenous onlay bone grafts vs. alveolar distraction osteogenesis for the correction of vertically deficient edentulous ridges: a 2-4-year prospective study on humans

Objectives: The purposes of this study were to compare: (a) autogenous bone grafts (ABG) and distraction osteogenesis (DO) for their ability in correcting vertically deficient mandibular ridges and their capability in maintaining over time the vertical bone gain obtained before and after implant placement; and (b) the survival and success rates of implants placed in the reconstructed or distracted areas. Material and methods: In a 2-year period (2001-2002), 17 patients presenting with vertically atrophied partially edentulous mandibles requiring implant-supported prosthetic rehabilitation, were included in this study. Patients were randomly assigned to two groups. Eight patients (group 1) were treated with ABG harvested from the mandibular ramus, while nine patients (group 2) were treated by means of DO. In group 1, patients received implants 4-5 months after the reconstructive procedure, while in group 2 implants were placed at the time of distraction device removal (approximately 3 months after the completion of distraction). A total of 19 endosseous implants were placed in group 1, and 21 implants were placed in group 2 patients. For both groups, after an additional 3-5-month period, prosthetic rehabilitation was started. Results: Bone resorption before implant placement was significantly higher in group 1 (P=0.01), while no statistically significant differences were found between the two groups as far as survival and success rates of implants and peri-implant bone resorption after the start of prosthetic loading were concerned. Conclusion: The results suggested that: (a) both techniques may effectively improve the deficit of vertically resorbed edentulous ridges; (b) survival and success rates of implants placed in the reconstructed/distracted areas are consistent with those of implants placed in native bone.