不等力值远中移动尖牙的比较研究

A comparison of distal movement of canines with different level of force

目的 研究100g力与150g力远中移动尖牙后牙齿移动距离、根尖及根周硬组织的变化。方法 用OPAK直丝弓矫治技术对25名青少年患者在0．018×0．025”ss的方丝上，应用Ni-Ti螺旋弹簧分别以初始100g及150g力牵引尖牙向远中，四周后分别用游标卡尺及Digora分析法比较牙齿移动距离、牙根长度及牙槽骨高度及密度的变化。结果 应用100g力及150g力移动尖牙向远中一月，两者的尖牙移动距离有显著性差异（p〈0．01），150g力侧移动距离大于100g力侧。而牙根长度、牙槽骨高度及密度无显著性差异（p〉0．05）。结论 临床上OPAK矫治器在0．018×0．025不锈钢方丝上应用150g力移动尖牙向远中是行之有效而且是安全的。

Objective To study the differene of distal movement of canines with 100 g and 150 g force on the distance and changes of periapex. Methods 25 juvenile patients were treated with a straight wire appliance. The device for canine distal movemeat was Ni Ti spring which produced originally 100 g and 150 g force respectively The moving distance, root length, height and density of alveolar bone were compared with the use of vernier caliper and the analysis of Digora after four weeks. Results There was significant difference on canine moving distance, which showd 150 g force produced longer distance（p〈0. 01）. But there were no significant differences on the measn rements of root length, height and density of alveolar bone after four weeks（p〉0. 05）. Conclusion It is safe and more effective for orthodontists to use 150 g force for distall retraction of canines.