直丝弓排齐阶段两种远移尖牙方法的比较

Comparason of elastic traction and canine lace back in distal movement of canines used in the aligning stage of preadjusted appliance

目的:比较直丝弓矫治器排齐阶段2种远移尖牙的方法即尖牙向后结扎法和弹性链状圈牵引法的优缺点。方法:将50例拔除4个第一前磨牙的正畸病例随机分为2组,均使用同种国产直丝弓矫治器,排齐阶段分别采用上述2种方法进行矫治,排齐前后利用模型测量和X线头影测量进行统计学分析。结果:上颌前磨牙颊尖之间、下颌磨牙的4个牙尖之间的宽度变小、尖牙牙冠远中倾斜角度、尖牙远中移动距离和速度、下颌磨牙牙冠近中倾斜角度以及上、下切牙的舌向倾斜内收的变化,牵引法均大于结扎法;上、下颌磨牙近中移动距离的变化,牵引法小于结扎法;以上变化均有显著性差异。其余变化2种方法之间未见显著性差异。结论:2种方法应用于直丝弓矫治器排齐阶段均取得了远移尖牙的效果,然而,必须采取相应的控制支抗的措施以避免其各自的不利影响。

Objective：To compare the effects of distal movement of canines between elastic traction and canine lace back in the aligning stage of preadjusted appliance. Methods ：50 cases with Angle I malocclusion were divided into two groups after first premolar extraction. Patients in both groups were treated by the same kind of preadjusted appliance in the aligning stage. Canine lace back was used in one group and elastic traction in another. Treatment was countinued for 12 weeks. Measurements of the dental models and the cephalograms were conducted before and after treatment. Results：Compared to the canine lace back, the decrease of the width between the cuspids of upper premolars and that between that of lower molars, the increase of the angle of the distally tipped canines and the mesially tipped lower molars and the lingually tipped incisors, the higher speed and larger distance of distal moving canines were achieved more easy with elastic traction. On the contrary, the larger distance of mesial moving molars were attained with canine lace back. The differences of all the measurements above between the two methods were significant（P 〈 0.05 or P 〈 0.01 ）. Conclusion ： In the aligning stage with preadjusted appliance, the two methods of distal moving canines show different speed and outcomes. It is important to choose the proper method and apply the respective controls to prevent the reverse influences.