Periodontal tissues changes in tooth-borne distraction osteogenesis: an experimental study of closure of wide alveolar bone defects in dogs

We studied changes in periodontal tissue during maxillary dentoalveolar distraction osteogenesis using an intraoral tooth-borne distractor to close wide alveolar defects in four dogs. The dentoalveolar monofocal transport disc was made by complete horizontal subapical and vertical interdental osteotomy. Gradual distraction was started after a latency period of seven days at the rate of 0.4 mm twice a day. We measured the displacement of the supporting tooth and the anchoring tooth, and took successive radiographs. On days 0, 14, 28, and 70 after distraction, the dentoalveolar segments were harvested for histological examination. There was periodontal hyperplasia in the tissues of the tension side, and absorption in the stress side. In the early period of consolidation, there was inflammation and local destruction of periodontal tissues, but the changes reversed over time. The anchoring tooth was not displaced and the periodontal tissues did not change. Morphological changes in the periodontal tissues of the supporting tooth were moderate and, like the physiological changes of the periodontal ligament of the orthodontic tooth, could be reversed if the rate and duration of distraction were correct.