安氏Ⅱ类错拔除第一磨牙矫治面部高度的变化

Vertical Height Changes of Angle Class II Patients Treated with First Molar Extractions

目的:评估成人安氏Ⅱ类错拔除第一磨牙矫治前后面部高度的变化情况。方法:对15例成人安氏Ⅱ类错患者因第一磨牙严重龋坏,拔除1～3颗第一磨牙,采用0.022×0.028英寸直丝托槽,常规直丝弓技术矫治,对术前术后头影测量结果进行配对t检验,评价面部垂直向高度的变化情况。结果:矫治疗程19～32个月,平均为25个月。颌面部垂直向高度的变化:FH-MP、SN-MP减小,OP-SN、PP-MP增大,且OP-SN矫治前后变化有统计学意义(P<0.05);L1-MP减小,U1-PP增大,矫治前后变化有统计学意义(P<0.05),U6-PP减小、L6-MP增大,但结果无统计学意义。FMIA、y-轴角、NBa-PtGn减小,但结果无统计学差异。结论:安氏Ⅱ类错拔除第一磨牙矫治,下后牙及上前牙伸长,下切牙压低,平面角增大,牙合平面顺时针旋转。关闭第一磨牙拔牙间隙前后,颌面部垂直向高度无明显变化,但对高角及开患者仍需要加强控制。

Objective： To investigate the vertical height changes of Angle class II patients treated with first molar extractions.Methods： Fifteen cases with the extraction of one to three first molars due to severe caries were treated with straight wire appliance（0.022 slot bracket）.During the treatment,extra-oral anchorage were not used,and we investigated the vertical height changes by analyzing cephalometric measurements pre-and post-treatment by paired t-test.Results： Average treatment period was 25 months（19 to 32 months）.The vertical height changes： FH-MP,SN-MP decreased,whereas OP-SN,PP-MP increased,and OP-SN increased significantly（P〈0.05）.L1-MP decreased significantly（P〈0.05）,U1-PP increased significantly（P〈0.05）.U6-PP decreased,L6-MP increased,but the results were not significantly（P〈0.05）.FMIA,y-axis angle,NBa-PtGn decreased,but not significantly.Conclusion： During closing the extraction space,L6-MP,U1-PP increased,L1-MP decreased.The occlusal plane had occurred clockwise rotation.The vertical height was not significantly changed,which would be good to deep overbite,but should be pay attention to high-angles and open bite cases.