直丝弓矫治技术治疗安氏Ⅱ/Ⅰ错畸形的机制

Mechanism of straighwire appliance technique on treating angleⅡ/Ⅰ malocclusions

研究直丝弓矫治技术治疗安氏Ⅱ／Ⅰ错畸形的机制。方法：对２８例采用直丝弓矫治技术治疗的安氏Ⅱ类Ⅰ分类错患者治疗前后Ｘ线头颅测量结果进行统计学分析。结果：治疗后 ＵＩ－ＮＡ角平均减少 １０．６８°， ＵＩ－ＳＮ角平均减少１１．３９°， ＵＬ－ＮＡ平均减少 １．３６ ｍｍ， ＬＩ－ ＮＢ角平均减少２．５°，ＬＩ－ＭＰ角平均减少 ３．０°，ＬＩ－ＮＢ平均减少 １．４ ｍｍ， ＬＩ－ ＡＰ，平均减少 １．２ ｍｍ，ＳＮ－ＯＰ角平均增加 １．８２°。治疗前后上下切牙交角与上下切牙的倾斜度和突度的差值呈负相关，上切牙各倾斜度和突度的差值彼此呈正相关，下切牙各倾斜度和突度的的差值彼此呈正相关。结论：直丝弓矫治技术治疗安氏Ⅱ类Ⅰ分类错■主要是通过移动牙齿的掩饰性矫治完成的，上下颌牙的位置是协调变化的，拔牙矫治并未影响面高。

Aim: To find out the mechanism of MBT Straighwire Appliance Technique on treating Angle Ⅱ/Ⅰ malocclusions. Methods: Twenty - eight cases of Angle Ⅱ/Ⅰ malocclusion were involved. Pre and Post treatment cephalometric radiographs were taken, measured and evaluated. Results: After treatment, the UI - NA Angle decreased by 10. 68° on average, UI - SN angle by 11. 39°, UI - NA distance by 1 .36 mm, LI-NB Angle by 2.5°, LI - MP Angle by 3.0°, LI - NB disgrace by 1 .4 mm, LI - AP distance by 1. 2 mm, and the SN - OP angle increased by 1. 82° on average. The Upper Lower Incisors angle was in negative correlation respectively with the Inclination and Protrusion value of Upper and Lower Incisors before and after treatment. The Inclination and Protrusion values of Upper Incisors were in posi- tive correlation with each other. And that of the Lower Incisors were the same. Conclusion: The effect of orthodontic treatment to Angle Ⅱ/Ⅰ malocclusion is achieved mostly by compensation with tooth movement. The relatively location between Upper and Lower Incisors changes harmoniously. And Face Height is not influenced during extraction treatment.