下颌第二、第三磨牙并列阻生的正畸矫治

目的探讨下颌第二、三磨牙并列阻生的正畸治疗方法，评估其效果。方法选择下颌第二、第三磨牙并列阻生患者6例、共8对，拔除下颌阻生第三磨牙，采用固定矫治器结合磨牙带环焊多曲推簧直立装置，对水平阻生的第二磨牙进行竖直，使第二磨牙远中直立移动。结果水平阻生第二磨牙全部被直立，达到正常的殆平面，获得良好功能邻接关系及根平行。X线片示原阻生牙冠所占空间为正常牙槽骨组织所修复。下颌阻生磨牙竖直时间为5～14个月，平均为8．63个月。结论在下颌第二、三磨牙并列阻生患者中，拔除下颌第三磨牙，有利于第二磨牙的直立。自制带环焊多曲推簧及粘接拉钩的磨牙竖直技术能有效地使水平阻生的第二磨牙产生快速的远中直立移动。

Orthodontic uprighting of impacted mandibular second molars

Objective To assess the treatment method and outcome of horizontally impacted mandibular second molars. Methods Six patients with mandibular impacted second and third molars, including 8 horizontally impacted mandibular second molars, were treated with fixed appliance in conjunction with molar band soldered with pushing spring. Crowns of horizontally impacted mandibular second molars were moved distally and uprighted after impacted mandibular third molars were extracted. Results All horizontally impacted mandibular second molars were uprighted. Good occlusion and root parallel were also achieved. The panoramic radiographs revealed that uprighted mandibular second molars were surrounded by normal alveolar bone. Mean treatment period was 8. 63 months （5 to 14 months）. Conclusions The orthodontic molar uprighting technique was effective in uprighting and distalizing the horizontally impacted mandibular second molars.