Comparison of Mandibular and Maxillary Sites Augmented With Autogenous Iliac Grafts

Objectives: Autologous bone grafting is a way to treat severe atrophy of the jaw when implant-supported rehabilitation is otherwise not possible. The objective of this study was to compare the tissue mineral density and microarchitecture of maxillae and mandible after ridge augmentation with autogenous corticocancellous bone grafts harvested from the ilium.
Methods: Five patients (4 female, 1 male, mean age 54 yrs.) received autogenous iliac bone graft augmentation for dental implant placement. After IRB approval, 18 human bone biopsy samples were removed from anterior maxillae and mandible of patients after 5 months of bone graft healing, before implant placement and analyzed using three dimensional microcomputed tomography (Micro-CT) with 6.6 micron resolution. Histogram of CT attenuation values, which are proportional to bone tissue mineral densities, were used to obtain mean (Mean) and standard deviation (SD). The 3D architectural parameters of the bone were obtained for trabecular bone volume fraction (BV/TV) and trabecular number (Tb.N). BMD was computed by dividing the sum of CT attenuation values by the total volume of a region of interest. Mixed mode analysis of variance with Tukey-Kramer post hoc tests were performed to compare the grafted and native bone specimens between mandible and maxilla. Significance was set at p<0.05.
Results: The native mandibular bone had greater values of BMD and Tb.N than the native maxillary bone (p=.038). However, BV/TV, mean, and SD values were not significantly different (p=.092). Those parameters of the grafted bone were not significantly different between the mandible and maxillae (p=.169).
Conclusions: The current results indicated that native mandible may provide more stable sites for implantation with more bone quantity than the native maxillae. However, the bone quality at the tissue level was comparable regardless of oral anatomical sites and grafting.