Inlay-onlay grafting for three-dimensional reconstruction of the posterior atrophic maxilla with mandibular bone

This prospective study describes and evaluates a surgical approach for 3D reconstruction of the posterior maxilla with autogenous mandibular bone in 16 patients (mean age 51 years). Bone blocks were harvested from the mandible and used as lateral or vertical block grafts (onlay); they were also partially milled and used for sinus elevation (inlay). In 4 cases, anorganic bovine bone was added at the periphery of the blocks. 4 months after grafting, implants were placed in a second operation and loaded after 12 weeks. Lateral and vertical augmentations were measured immediately after grafting and at re-entry for implant placement. Mean lateral augmentation performed was 5.5mm, reduced to 4.3mm (p<0.01) after 4 months' healing. Mean vertical augmentation was 3.2mm, reduced to 2.1mm (p<0.01) after healing. The amounts of lateral and vertical graft resorption were similar (1.2mm vs. 1.1mm) but were different when compared with the original graft (22% vs. 34%). 49 implants were placed 4 months after grafting. Implant parameters were evaluated after 32-48 months follow up and demonstrated 100% survival rates. The use of mandibular bone grafts for 3D augmentation of the posterior maxilla has shown good results and minor complications.