Reconstruction of the posterior mandible with onlay cranial grafts before implant placement: a personal experience of 172 cases operated in 18 years

Abstract

Background: The purpose of this study is to present the protocol and results of pre-implant reconstruction of the posterior mandible with cranial bone graft apposition from 1997 to the present. Methods: 172 cases of bone resorption were grafted over a period of 18 years. Onlay bone grafting was used for horizontal resorption. For vertical resorption, a framework was made of cortical bone filled with bone marrow particles. Pre- and postoperative scans were taken and used to measure the bone augmentation and results. All patients were recalled for radiographs to assess the periimplant resorption and implant long-term survival in the grafted bone. Results: The results showed an average bone augmentation of 7.8 mm in cases of vertical resorption and 7.2 mm in cases of horizontal resorption. In cases of mixed resorption results showed average bone augmentation of 6.67 mm vertically and 8.1 mm horizontally. Complications included lip and chin hypoesthesia in 6.4%, bone graft exposure in 2.7% and partial, or complete, resorption of the grafts in 5.2%. The interval between the graft and the placement of bridges was 13.3 months. The success rate of implants was 86.6%, while the rate of implant survival was 97.7%. The radiographic mean follow-up of patients was 52 months (4.3 years). Conclusion: The results of this study suggest that the onlay graft technique, except for rare cases of very low occlusal space, is possible in all situations (even the most extreme) and has many benefits and very good results for bone augmentation and implant placement.