OBJECTIVE The primary goal of this study was to compare bone-to-implant contact (BIC) in alveolar bone augmented by distraction osteogenesis with BIC in alveolar bone augmented by onlay iliac crest grafting. METHODS Alveolar bone defects were created bilaterally in 5 American foxhounds, and after healing, bone augmentation was accomplished using distraction osteogenesis on 1 side of the jaw and onlay grafting on the other. Twelve weeks after consolidation, implants were placed in augmented and control sites. The animals were sacrificed and the jaws harvested for histologic analysis after an additional 8 weeks. RESULTS The mean BIC was 54.7% +/- 14.6% for implants placed in distracted sites, 53.8% +/- 11.8% for sites where an onlay graft was used, and 51.2% +/- 14.4% for control sites. Significant differences in BIC were noted between experimental and control sites only at the apical third of the implant (19.8 +/- 1.8 for distracted sites; 15.5 +/- 1.5 for grafted sites; 8.0 +/- 0.5 for control sites; P < .05). CONCLUSIONS The data showed that both distraction osteogenesis and onlay grafting produce sufficient bone for implant placement. There were no differences between procedures in regard to BIC after 8 weeks. CONCLUSIONS These data suggest that both onlay grafting and vertical distraction are appropriate methods for bone augmentation prior to implant placement.