Biologic response of rapid tooth movement with periodontal ligament distraction.

INTRODUCTION: Length of treatment is a complaint of many orthodontic patients. The purpose of this study was to evaluate the security and feasibility of rapid tooth movement with periodontal ligament distraction.

METHODS: Eight male beagles, aged 13 to 16 months, were used in this study. Extraction of the mandibular second premolar and alveolar surgery to reduce the osteal resistance on the mesial side of the extraction socket were performed on the experimental side. Then a device was placed to distract the first premolars distally on the experimental side; on the control side, the first premolars were distalized with nickel-titanium coil springs. The beagles were killed in the first, second, fourth, and eighth weeks after orthodontic force application.

RESULTS: The first premolar on the experimental side moved more rapidly than that on the control side (P <0.05). Histologic data indicated that more new bone was deposited on tension area of the experimental side than on the control side. Active and extensive bone resorption in the compressive area and bone deposition in the tension area were observed on the experimental side.

CONCLUSIONS: These results suggest that the periodontal ligament can be rapidly distracted without complications. The rapid orthodontic tooth movement by distracting the periodontal ligament cannot be emulated by current conventional orthodontic concepts and methods.