Effects of intermaxillary factors and distraction frequency on rapid teeth movement through reducing resistance and distraction

Objective: To investigate the effects of intermaxillary factors and distraction frequency on rapid teeth movement through reducing resistance and distraction by establishing experimental animal models. Methods: Twelve Beagle dogs were equally divided into two groups randomly. One group was randomly operated on with different treatments in the maxillary: distraction twice a day through reducing resistance, distraction six times a day through reducing resistance, and conventional distraction. Each treatment was carried out on 4 sides. The other group underwent the same operation in the mandible. Distance of teeth transportation, pulp vitality, tooth mobility and cone-beam computed tomography (CBCT) images were evaluated at two time points: 15 days after distraction and 30 days after distraction. Results: After 15 days of distraction, the distance of teeth transportation had no significant difference for intermaxillary discrepancy with frequencies of 2 q·d^-1 and 6 q·d^-1 through reducing resistance and distraction (P>0.05), and the speed of movement was significantly higher than that of conventional distraction without obvious side effects (P<0.05). Conclusion: Teeth can be moved rapidly through reducing resistance and distraction in the maxillary and the mandible, and distraction with high frequency is more beneficial to physiological reconstruction of teeth.