Long-term assessment of early alveolar bone grafts using three-dimensional computer-assisted tomography: a pilot study.

Fifteen patients with complete unilateral cleft lip and palate who had primary alveolar bone grafting were studied with computer-assisted tomography at a mean age of 12 years. Keeping the maxillary alveolar crest parallel to the plane of the scan, 1.5-mm cuts of the maxilla were made from the infraorbital rim to the gingival third of the crowns of the teeth. A single operator reformatted the data into three-dimensional images using the Maxiview 3200 computer workstation. This allowed examination of the position, size, and spatial relationship of the grafted area and quantification of the amount of bone coverage of root surface and bone height of the alveolus in or adjacent to the graft site. Ten patients showed a lateral incisor in the line of the cleft. The average bony coverage of these tooth roots was 76.5 percent. In the five patients in whom there was lateral incisor agenesis, the canine root had average bony coverage of 82.6 percent. The average height of bone at the lateral incisor was 8.7 mm; at the canine, 14.1 mm. In two patients in whom there was only 42 percent tooth root coverage, the teeth were still viable, stable, and without mobility. Computed tomographic (CT) scans of the 15 patients demonstrated good graft survival with adequate volume. The functional and aesthetic status of the dentition in the area of the cleft also was demonstrated.