颌间因素及牵引频率对减阻牵张牙齿移动速度的影响

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

目的通过建立动物模型,探讨颌间因素及牵张频率对减阻牵张快速牙移动效率的影响。方法 Beagle犬12只,随机分为两组,每组6只。一组随机在上颌两侧实施不同的术式:减阻牵张频率2次/d、减阻牵张频率6次/d,常规牵引。每种术式各4个单侧。另一组采用相同的术式方法在下颌两侧随机实施。分别于加力15d及保持30d时测量牙齿移动的距离,测定牙髓活力、松动度,拍摄口腔锥形束CT(CBCT)影像。结果加力15d时,减阻牵张措施下,上、下颌及2、6次/d牵张频率间移动牙的移动距离无显著性差异(P>0.05),减阻牵张下牙齿移动速度明显快于常规方法(P<0.05),且不伴有明显的不良反应发生。结论减阻牵张技术能够实现上、下颌牙齿的快速移动,高频牵引更利于牙齿的生理性改建。

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 2q·d^-1 and 6q·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.