Incorporation of anterior iliac crest or calvarial bone grafts in reconstructed atrophied maxillae: A randomized clinical trial with histomorphometric and micro-CT analyses.

Background Autologous bone grafts have been applied successfully to severely atrophied maxilla via a preimplant procedure. Differences in graft incorporation at the microscopic level can be the decisive factor in the choice between anterior iliac crest and calvarial bone. Purpose To compare conversion of anterior iliac crest bone and calvarial bone 4 months after grafting of the edentulous maxilla. Materials and methods Twenty consecutive patients were randomly assigned to either anterior iliac crest (n = 10) or calvarial (n = 10) bone harvesting to reconstruct their atrophied maxillae. Biopsies were taken from both fresh bone grafts and reconstructed maxillae after 4 months healing, at time of implant placement. Micro-CT, histomorphometric and histological analyses were performed. Results Micro-CT analysis revealed that both the anterior iliac crest and calvarial bone grafts retained their volume and bone mass after being incorporated in the maxilla, but with a favor for calvarial bone grafts: calvarial bone grafts had a higher mineral density before and after incorporation. Both bone grafts types were well incorporated after 4 months of healing with preservation of bone volume and mineral density. Although the fresh bone biopsies were similar histomorphometrically, after 4 months of graft incorporation, the osteoid percentage and osteocyte count remained higher in the anterior iliac crest bone whereas the percentage of bone was higher in the calvarial bone grafts compared to the anterior iliac crest bone grafts. Conclusions Both donor sites, that is, anterior iliac crest and calvarial bone, are well suited to provide a reliable and stable basis for implant placement 4 months after grafting with mineral density, porosity, and resorption rate in favor of calvarial bone grafts.