A clinical study of changes in the volume of bone grafts in the atrophic maxilla.

OBJECTIVES: To evaluate the volumetric changes in bone grafts to the severely atrophic edentulous maxilla over 6 months. METHODS: Ten edentulous patients received autogenous bone as buccal onlay grafts to the maxilla and bilaterally particulate bone grafts to the maxillary sinus. Two mm contiguous axial CT scans were obtained 1 to 2 weeks and 6 to 7 months postoperatively. The area of each graft was measured and the volume calculated according to the formula V(graft)=Sigma of areas x the thickness of each section. RESULTS: The volume of the inlay and onlay grafts was reduced by an average of 49.5 and 47% respectively of the initial volume. The coefficient of variation was greater in the onlay group (0.79) compared with the inlay group (0.38). CONCLUSIONS: The volumetric changes in buccal onlay and sinus inlay grafts after 6 months of healing seem similar although there was a wide range in both groups.