拔除病变第一磨牙后上、下颌第三磨牙正畸近移疗效比较

目的探讨拔除病变第一磨牙后上、下颌第三磨牙近移进行正畸治疗的效果。方法收集20例第一磨牙病变同时需要进行正畸治疗的患者,平均年龄18.6岁。根据患者口内情况将患者分为2组,每组10例。第一组上颌无明显拥挤,仅拔除病变的上颌第一磨牙,下颌拔牙或非拔牙矫治;第二组下颌无明显拥挤,仅拔除病变的下颌第一磨牙,上颌牙列拔牙或非拔牙治疗。全部病例均采用方丝弓矫治器,排齐整平牙列,关闭拔牙间隙,精细调整咬合关系。结果 20例患者都达到良好的矫治效果,双侧的磨牙、尖牙均达到良好的咬合关系。上颌第三磨牙前移平均8.8个月,平均近移7.94mm;下颌第三磨牙前移平均9.7个月,平均近移7.12mm。结论上、下颌由于存在骨质结构的差异,拔除无法保存的第一磨牙后,上颌第三磨牙近移比下颌磨牙较快。扶正簧的使用使倾斜的下颌磨牙得以直立。

Comparative study of the movement of upper and lower third molars after extraction of decayed first molars in orthodontics

Objective To compare the effects of the mesial movement of upper and lower third molars after the decayed first molar extraction in orthodontics.Methods Twenty patients aged from 15 to 32 years,with malocclusion and decayed first molars were selected.They were divided into two groups with 10 cases in each group.The decayed maxillary first molars were extracted in group one and decayed mandibular first molars in group two.All patients were treated with Edgewise appliance.The procedure included leveling dentition,closing extraction spaces and adjusting occlusal relationships.Results The treatment outcome in all patients was excellent with good occlusion and function.The upper third molar movement took an average of 8.8 months with mesial movement of 7.94mm in average.The lower third molar movement took an average of 9.7 months with mesial movement of 7.12mm in average.Conclusion Movement of upper third molars is faster than that of the lower third molars.Lower third molars sometimes need up-righting.