颌间Ⅲ类矫形力对青春期恒河猴上颌骨作用的头影测量研究

目的：通过建立颌间Ⅲ类矫形动物实验模型,评价持续的颌间Ⅲ类矫形力对上颌骨的作用及动态变化规律。方法：选用青春生长发育期雌性恒河猴6只,分为实验组（3月、6月各2只）和对照组（3月、6月各1只）,实验组戴用Ⅲ类双阻板磁力矫治器,对照组不戴。实验过程中,定期拍摄X线头颅侧位片,图像输入计算机头影测量系统进行测量分析。结果：（1）与对照组相比,实验组位发生明显改变;（2）头影测量表明,对照组表现为向下向前发育,实验组矫形治疗后上颌骨相对于颅骨发生了向前的移位和少量旋转,同时其长度出现增加;（3）发现上颌骨的空间位置变化主要发生在开始矫治的两个月内,长度增加的最大值出现在第三个月左右;（4）上颌骨对矫形力作用的反应有一定的限度,增加矫形力作用时间并不能进一步促进上颌骨的更多空间变化和长度的增加。结论：Ⅲ类矫形力可以显著改变上颌骨的空间位置和固有长度,空间的位移比长度的改变出现得早。

The effect of class Ⅲ intermaxillary orthopedic force loading on the maxilla of puberty rhesus： a cephalometric study

Objective：To evaluate the effect and the regularity of time-related change of class Ⅲ intermaxillary orthopedic force loading on the maxilla of puberty rhesus.Methods：The animal model was established with 6 puberty female rhesus,which were randomly divided into experimental group（wore class Ⅲ twin-block magnet appliance,each 2 rhesus for 3 and 6 month respectively） and control group（did not wear any appliance,each 1 rhesus for 3 and 6 month respectively）.The lateral radiograph was taken monthly and computer-aided system was used for lateral cephalometry.Results：（1）Compare to the control group,the occlusion of experimental group were changed obviously;（2）Cephalometric measurement showed that normal forward and downward development was observed in control group and maxilla moved forward and slight clockwise rotation was observed in experimental group;（3）The spatial change of maxillary was occurred in the first two month,but the maximum value of length was achieved at the third month;（4）There was a limit exist in the reaction of the maxilla to orthopedic force,additional loading can not promote more spatial change or length increase.Conclusions：Class Ⅲ orthopedic force can obviously change the spatial position and length of maxilla and the former occurs earlier.