Comparison of Healing of Allograft and Autogenous Bone Implanted in the Skull Defect of Beagle Dog: Preliminary Animal Study

Purpose: The purpose of this study was to evaluate the healing process after autogenous and allogenous bone grafts for calvarial bone defects in beagles.Materials and Methods: Two defects were formed in the skulls of two beagles and then grafted with a freeze-dried bone allograft (Double-Oss) and an autogenous bone chip, respectively. The clinical, radiographic, and histomorphometric examination results of the specimens taken 4 and 8 weeks after bone grafting were analyzed.Results: The clinical, radiographic, and histological assessments revealed that 4 and 8 weeks after transplant, the beagle that received an autogenous bone graft was more likely to have high new bone formation than the beagle that had an allogenous bone. Four weeks after the transplant, the proportions of new bone formation were 11.5% and 35.8% in the allogenous and autogenous bones, respectively. Eight weeks after the transplant, the proportion of new bone formation with the allogenous bone increased significantly to 41.4% but was still less than the 65.6% with the autogenous bone.Conclusion: The amount of new bone formation was smaller and the formation rate was slower with allogenous bone graft than with autogenous bone graft.