肌激动器联合不同口外弓施力点治疗儿童骨性Ⅱ类错颌畸形的疗效研究

Comparison of the Treatment Effectiveness between Two Vanbeek Activators with Different Load-Points of Extraoral Force in the Treatment of Children’s Skeletal Class Ⅱ Malocclusion

目的研究肌激动器配合不同口外弓施力点治疗儿童骨性II类错颌畸形的疗效差异。方法收集2019年1月—2020年12月绍兴市中医院口腔科治疗的骨性Ⅱ类错颌50例患儿作为研究对象,通过分发随机信封将其分为试验组与对照组,各25例。试验组使用改良头帽肌激动器(Vanbeek Activator),口外弓位置前移自上中切牙及侧切牙间伸出基托;对照组使用传统Vanbeek Activator,口外弓自上颌第一、二前磨牙间伸出基托。收集患儿治疗前后头颅定位侧位片进行头影测量。结果治疗后试验组下颌平面角、前后面高比和上颌牙合平面角的减小量显著高于对照组,差异有统计学意义(P<0.05);治疗后两组上颌矢状向位置(SNA角)、下颌矢状向位置(SNB角)、上下颌骨相对位置(ANB角)、Y轴角、下面高比例、上下中切牙角等比较,差异无统计学意义(P>0.05)。结论改良Vanbeek Activator的施力点位于上颌骨及上牙弓阻抗中心前部,可使上下颌骨发生一定程度逆时针旋转,有利于均角偏高角骨性II类错颌患儿的垂直向控制。

Objective To compare the treatment eff ectiveness of two kinds of Vanbeek activators with diff erent load-points of extraoral force in the treatment of children’s skeletal class Ⅱ malocclusion.Methods Thirty cases were included from January 2019 to December 2020.In the experimental group,improved Vanbeek activators with facebows extending between central and lateral incisors were used.In the control group,conventional Vanbeek activators with facebows extending between fi rst and second premolars were used.Pretreatment and post-treatment lateral cephalometric radiographs of patients were collected for measurement.Results After treatment,the MP-FH(P=0.014),ANS-Me/Ar-Go ratio(P=0.042)and OP-FH(P=0.013)in the experimental group decreased signifi cantly than the ones in the control group.between two groups in the change of SNA,SNB,ANB,Y axis angle,ANS-Me/N-Me ratio,U1-SN,and L1-MP,the difference is not statistically significant(P>0.05).Conclusion The load-point of improved Vanbeek activator was in front of the resistance centers of upper arch and maxilla,which led to counter clockwise rotation of jaws and was eff ective in vertical control in moderate to high angle children with skeletal classⅡmalocclusion.