Three-dimensional alveolar bone morphology analysis using computed tomography

The purpose of the present study was to determine whether the use of 3-dimensional computed tomography (3DCT) is an effective method of imaging bone defect morphology caused by periodontal disease. A total of 186 sites from 9 patients were examined. Periodontal parameters were recorded after initial therapy. For the evaluation of bone resorption and root morphology, computed tomography (CT) scanning was performed and then CT images were reconstructed for 3-dimensional evaluation. Immediately prior to the surgery, bone sounding measurements were done under local anesthesia. The denuded bone measurement during periodontal surgery represented the true bone level. To compare the bone level obtained from 3DCT images with the true bone level, the examiner, without being informed of the patient's condition, traced the cemento-enamel junction (CEJ) and apical extent of the bone levels on the images of 3DCT, and measured the vertical distance between the CEJ and bone. The mean difference between 3DCT and the true bone level was 0.41+/-2.53 mm (mean+/-SD). The correlation between them showed a highly significant linear regression (R=0.75). However, the mean difference between the bone sounding level and the true bone level was 0.22+/-1.49 mm (R=0.91). Thus, bone sounding was slightly more accurate than 3DCT, but there was no significant difference between these two assessments (P >0.05). The results of present study indicate that 3DCT has the potential to allow precise assessment of bone defect caused by periodontal disease.