Corticocancellous fresh-frozen allograft bone blocks for augmenting atrophied posterior mandibles in humans

Background: Allograft fresh-frozen bone (FFB) is an alternative to autogenous bone for oral implantation due to bone quantity availability and lower morbidity for patients. Few specific studies about the use of FFB for reconstructing the posterior mandibular alveolar crest have been conducted. Objective: The objective of this study was to evaluate histological, histomorphometrical, and volumetric aspects of FFB allografts used to augment atrophied posterior mandible bone ridges. Materials and methods: Sixteen hemi-mandibles of twelve patients presenting with critical alveolar atrophy were three-dimensionally reconstructed using corticocancellous FFB. Thirty blocks were fixed with titanium screws and covered with particulate bovine bone mineral and collagen membrane. Volumetric data were obtained by cone beam computed tomography analysis after 6 months, implants were inserted, and bone biopsies were harvested and sent for histological and histomorphometric analyses. Results: The blocks were distributed between nine female and three male patients (mean age, 50.9 ± 8.3 years). Thirty implants were installed, and the implant survival rate was 96.66%. Histology demonstrated newly formed vital bone contacting residual acellular allograft bone and connective tissue. The histomorphometric analysis showed 18.9 ± 8.1% newly formed bone and 32.5 ± 14.8% allograft residual bone. Graft absorption was 45% for height and volume, and both measures were significantly different (P < 0.001). Conclusion: Fresh-frozen allografts are a viable alternative for reconstructing an atrophied mandible in the posterior region, allowing for new bone formation, installation of implants, and prosthetic loading.