Long-term periodontal status of teeth moved into extraction sites

The present study was undertaken to assess the long-term periodontal status adjacent to teeth that had been moved orthodontically into extraction sites. Twelve persons with a mean age of 29.2 +/- 5.7 (SD) years, who had completed orthodontic therapy at least 10 years previously, were examined. The orthodontic treatment had included bilateral premolar extraction in only the maxilla. Interproximal tooth surfaces in the maxilla adjacent to the extraction sites (study group) were compared to corresponding tooth surfaces in the mandible (control group) with respect to plaque, visual inflammation, bleeding after probing, pocket depth, gingival recession, loss of connective tissue attachment, radiographic bone height, and root resorption. Statistical comparisons were made via analyses of variance and t tests. There were no differences between the groups for any clinical parameter except the presence of less visual inflammation in study subjects. Radiographically, there were no differences in crestal alveolar bone levels measured from the cementoenamel junction. Bone height evaluation by the Bjorn method showed less alveolar support in the study group. However, this was due to the influence of root resorption rather than an effect on crestal height. It was concluded that orthodontic movement of teeth into extraction sites had been without detrimental effect upon the adjacent periodontal status.