Volumetry of bone grafts by three-dimensional computed tomographic reconstruction: an animal study in the minipig.

OBJECTIVES: To evaluate the accuracy of 3D-CT reconstruction for determination of bone graft volume in an animal model. MATERIALS AND METHODS: Eight minipigs had bone graft reconstruction of an alveolar ridge defect. The true volume of the graft (VOL I) was determined by Archimedes principle before reconstruction. Following fixation, axial CT-scans (1 mm slice thickness with 50% overlap) were performed and segmented into grafted and residual bone for 3D-reconstruction. Using the volume tool of the 3D program the volume (VOL II) was calculated. RESULTS: There was a strong correlation between VOL I and VOL II (r = 0.93, P = 0.001). There was a tendency, which was not statistically significant, to overestimate the volume measured by 3D-CT. CONCLUSION: The volume of a bone graft can be determined by 3D-CT. However, further refinements of the technique are needed to improve the accuracy.