Three-dimensional interpretation of labiolingual bone width of the lower incisors. Part II.

For quantitative evaluation of the different imaging quality of cephalograms and computed tomography in the region of the lower incisors, the macroscopic and histological findings of specimens were compared with the corresponding radiological findings. After removal of the soft tissue from 11 mandibular dentate segments, 15 artificial bone defects of different dimensions were produced in the region of the lower incisors. In comparison with the microscopic jaw measurements, the mean labiolingual diameter of the frontal alveolar process of the single incisors was overestimated in the cephalograms by 0.3 to 1.2 mm. Most of the anatomical-radiological correlations of the cephalometric measurements was insignificant. Individual metric assessment of the labiolingual bone width or of the facial/lingual cortical bone plates or the identification of the artificial defects of lower incisors in the cephalograms were generally not possible. In the CT-images the mean labiolingual diameter of the frontal alveolar process of the single incisors was overestimated by 0.1 to 0.5 mm, but the correlations were highly significant. The facial/lingual cortical bone plates of the lower incisors were evaluated and measured in the CT-scans. Thirteen of 15 artificial bone defects (80%) were identified in the CT-scans. CT-scanning is the only imaging technique offering three-dimensional quantitative evaluation of the labiolingual alveolar bone width and the facial/lingual cortical bone plates.