Alveolar ridge augmentation: a comparative longitudinal study between calvaria and iliac crest bone grafrs

Insertion of endosseous implants is often difficult because of lack of supporting bone. In the case of severe atrophy of the jaws, a large volume of autogenous bone can be harvested from the iliac crest and calvaria. Both grafts undergo partial resorption with time, but the rate of bone loss has not been fully elucidated. The aim of this study was to evaluate the alveolar bone height gain (ABHG) obtained with iliac crest and calvaria bone grafts. Twenty-five patients had mandibular bone grafts, 32 had maxillary bone grafts, and 11 had both mandibular and maxillary bone grafts. Measures were made on preoperative, postoperative, and follow-up radiographs. A general linear model was used to evaluate the rate of ABHG plotted against months elapsed from the time of the operation to the time of follow-up. General linear model output showed a statistically significant effect for only the type of donor bone graft (P =.004), with a better ABHG for calvaria. The iliac crest bone grafts lost most of the ABHG in the first 6 months, whereas calvaria bone grafts lost ABHG over a greater interval of time. The type of bone graft is the strongest predictor of ABHG, and calvaria bone graft had a higher stability than did iliac bone graft. However, the gap in ABHG between the 2 grafts tended to decrease over time.