Long-term effect of orthodontic treatment on crestal alveolar bone levels.

It was the purpose of the present study to evaluate crestal alveolar bone levels in individuals (Study group, n = 104) who had completed orthodontic treatment at least 10 years previously and compare the findings with adults who had untreated malocclusions (Control group, n = 76). Crestal alveolar bone levels were determined on both bitewing and periapical radiographs by direct measurement from the cemento-enamel junction to the alveolar crest. Data from the individual tooth surface measurements were subjected to analyses of variance partitioned on group (Study vs Control), radiographic method, tooth type, dental arch and surface location. There was no significant difference between crestal alveolar bone levels between the study and control group. A Group/Tooth/Surface interaction occurred for the distal surface of molars. The alveolar crest level was significantly less in the orthodontically treated group. Examination of the numerical data suggested that the measured dimension was low relative to normal values, and this effect may have been related to tooth intrusion during orthodontic treatment. It was concluded that orthodontic treatment during adolescence had no detrimental long-term effect upon crestal alveolar bone levels.