不对称面弓单侧远移上颌磨牙的临床研究

Clinical Research on Asymmetry Headgear in Unilateral Molar Distalization

目的研究不对称面弓单侧远中移动上颌磨牙的临床应用及疗效。方法选择13例恒牙早期安氏Ⅱ^1亚类患者；下颌平面角为低角或均角；上牙弓拥挤度为轻、中度拥挤。其中，5例患者伴有上前牙中线偏斜。所有患者均采用非拔牙固定矫治，使用不对称面弓颈牵引远中移动单侧上颌磨牙，不对称面弓通过改变外弓的长度，调节加在上颌磨牙上的力量，在外弓的长臂端可获得较短臂端更大的远移磨牙力量。通过X线头影测量观察磨牙移动情况。结果口外力使用时间5—12个月，所有患者矫治结束磨牙关系均调整成中性；所有上颌中线偏斜均得以纠正。单侧磨牙远中移动平均3．2mm，对侧磨牙未见明显移动，保持原有的中性关系。有2例患者口外弓使用中出现上颌平面偏斜的情况。结论不对称面弓颈牵引可获得较满意的单侧磨牙远中移动效果，只要适应证选择得当，是纠正单侧磨牙远中关系及上颌中线偏斜行之有效的手段。

Objective The purpose of this study is to evaluate the effects of asymmetric headgear on tmilateral molar distalization. Methods 13 Class Ⅱ^1 subdivision patients with low or average angle and mild or moderate crowding were treated with asymmetric headgear without extraction. Evaluated the molar distalization through cephalometrics. Results All the molar relationship were corrected to Class I with the average 3.2 mm unilateral molar distalization. Occlusion shant occurred in 2 cases during the using of asymmetric headgear. Conclusion The asymmetric headgear is effective way to achieve unilateral molar distalizaion.