正畸治疗中拔除下颌第一磨牙的临床疗效观察

目的探讨拔除下颌第一磨牙病例的正畸治疗方法。方法对28例下颌第一磨牙严重龋坏的错[牙合]畸形患者，拔除1—2颗下颌第一磨牙，选用0．56mm槽沟直丝弓矫治器进行治疗。结果矫治完成时间为13—39月，平均为27．6月。矫治后前牙覆盖、覆[牙合]正常；后牙[牙合]关系良好，所有拔牙间隙关闭，牙根平行，面部侧貌协调。结论在拔除下颌第一磨牙病例中，精心设计、力量合适和方法得当可有效控制下颌第二磨牙近中倾斜或近中舌向扭转。拔除严重龋坏的下颌第一磨牙，同时直立阻生的下颌第三磨牙是保持牙弓完整性的良好选择。

Clinical Observation of Orthodontic Treatment Outcome in Patient with Mandibular First Molar Extractions

Objective To investigate the treatment methods in mandibular first molar extraction cases. Methods Twenty-eight cases with the extraction of 1 or 2 mandibular first molars due to severe caries were treated with straight wire appliance （0. 022 slot bracket）. Results Mean treatment period was 27. 6 months （ 13 to 39 months）. Normal overjet and overbite was achieved and good functional occlusion was established. All space was closed. Root parllel and facial profile harmony were gained. Conclusions In mandibular first molar extraction cases, second molar mesial inclination and mesiolingual rotation could be controlled properly.