Rapid tooth movement through distraction osteogenesis of the periodontal ligament in dogs

BACKGROUND Animal models are needed for the study of rapid tooth movement into the extraction socket through distraction osteogenesis of the periodontal ligament. METHODS Modified distraction devices were placed on eight dogs between the first and third mandibular premolars on the left sides; similar placement of traditional straight wise appliances on the right sides served as the control. The experimental distractors were activated (0.25 mm/d) twice a day and the control devices were activated (100 g) for two weeks with consolidation periods at weeks two, three, six, and ten. Two dogs were sacrificed at each consolidation time point; rates and patterns of tooth movement, loss of anchorage, and periapical films were evaluated, and the affected premolars and surrounding periodontal tissues were decalcified and examined histologically. General observations, X-ray periapical filming and histology examination were performed. RESULTS Distal movement ((3.66+/-0.14) mm) measured two weeks after modified distraction exceeded that achieved using the traditional device ((1.15+/-0.21) mm; P