口外弓单侧推磨牙向远中矫治安氏Ⅱ类亚类错临床报告

One side upper molar distalization for Class Ⅱ subdivision by face-bow apparatus

目的:探讨采用口外弓单侧推磨牙向远中矫治安氏Ⅱ类亚类错的临床效果。方法:选择恒牙列早期安氏Ⅱ类亚类错病例15例。年龄9～12岁,上颌第二磨牙尚未萌出,头影测量大致正常。取成品对称口外弓,在Ⅱ类磨牙关系一侧,在口外弓的内弓套入螺旋推簧,施加200 g力推磨牙远移。Ⅰ类咬合关系一侧,将内弓弯成U形,起到平衡作用。为防止磨牙移动,整排牙列连续结扎。结果:推磨牙远移的时间4～7个月,平均5.5个月。磨牙远移距离3.5 mm～6.0 mm,平均远移4.4 mm(即0.8 mm/每月)。磨牙远移结束后,II类磨牙关系改变成I类咬合关系,原来I类关系侧基本不变。磨牙远移到位后,再装配直丝弓矫治器完成矫治。结论:口外弓配合螺簧单侧推磨牙向远中,可顺利完成对安氏II类亚类错牙合的矫治,疗效满意。

Objective： Study of clinical results for correction Class II subdivision cases by the face-bow on the one side upper molar distalization. Method： 15 cases with Class II subdivision （ one Side is Class I relationship, the other side is Class II）, aged from 9-12 years old, were chosen for this clinical study. There is no eruption of upper second molars and the data of the cephelometfic is basically normal. The molar on the Class II side was bear 200 g force by coil-spring sourrouding the inner bow. The Class I side is only as a balance. While Class II molar relationship has been changed Class I,fixed appliance was used for further routine orthodontics.The distances of upper molar movement were measured by pre-and post using face-bow on the plaster models. Result：The time for upper molar distalization is of 5.5 months in average, ranging from 4.0-7.0 months. The distance of upper molar movement is of 4.4mm in everage, from 3.5 mm-6.0mm （0.8 mm / per month）.All cases for molar relationship will be changed from Class II to Class I, while the situations of Class I side is nearly no change.This paper will demonstrated a typical case. Conclusion： Our clinical study showed that this therapy upper molar were moved by face-bow on the side of Class II is simple, effective and satisfactory.