PURPOSE: The purpose of this study was to evaluate the effect of highpull J hook headgear(HPHG) on root resorption of maxillary incisors during orthodontic treatment.
目的：评价标准方丝弓配合高位J钩对正畸治疗中牙根吸收的影响。
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Object To evaluate the effects of class II malocclusion treated with MBT technique with highpullheadgear J hook.