Tooth rotation and alveolar bone loss
The purpose of the study was to examine the relationship between tooth rotation and alveolar bone loss in mandibular teeth of skulls. The material included 17 mandibles with 191 teeth. The jaws were found in excavations at the ruins of Dor. For each arch, a photograph of the occlusal was taken from a fixed reference point. Mid-central fossa and the extreme mesial and distal points of each tooth were marked on the photographic projection of each mandible. Data were transferred via a graphic plotter to a computer.
Alveolar bone loss was determined by measuring with a caliper the distance between the alveolar bone and the cementoenamel junction (CEJ) at the interproximal areas of each tooth. Teeth that were missing a definite landmark, such as central fossa, were excluded from the study. A Pearson's correlation coefficient was performed to evaluate the association between the degree of tooth rotation and alveolar bone loss. Teeth were also categorized to be either rotated or nonrotated at various levels: > 5, > 10, > 15, > 20, > 25, and > 30 degrees. Differences between the groups were assessed. A significant correlation was found between tooth rotation and alveolar bone loss, although it was not strong. In teeth with marked rotation (30 degrees or more), a much stronger and statistically significant correlation with alveolar bone loss was found. Mild rotation did not seem to be associated with bone loss, but when the threshold was set at 20 degrees or greater, mean bone loss was significantly greater for the rotated teeth (4.03 mm) than for the nonrotated teeth (3.49 mm).
In conclusion, these findings suggest that when extreme tooth rotation is present, more bone loss is present. [C.C.]
Peretz, B., and E.E. Machtei Quint Int, 27:465,1996