正畸治疗前倾阻生的下颌第三磨牙的根吸收风险研究

目的：探讨矫治前倾阻生下颌第三磨牙后牙根的改变和根吸收的影响因素,为临床医师提供风险预测的依据。方法：样本共10例（女性8名,男性2名,年龄15～32岁）,下颌第一恒磨牙已拔除或无保留价值,且伴同侧下颌第三磨牙前倾至水平阻生。矫治采用直丝弓矫治器,利用口内辅弓法后推下颌第三磨牙,再通过竖直簧直立第三磨牙。直立前、后拍摄全口曲面断层片进行测量。采用两相关样本非参数检验（Wilcoxon Signed Ranks Test）对矫治前后牙根长度的改变进行对比分析。结果：经过治疗,10例病例都取得满意的疗效。矫治后成人组阻生磨牙根长度有所减少,但未见统计学差异。青少年组牙根长度增加,差异具有显著性（P〈0.05）。结论：通过正畸手段直立阻生磨牙具有可行性和可靠性,为科学的权衡各种治疗方法提供帮助,为患者提供安全、有效的治疗方案。

Study on Root Resorption of Imnacted Mandibular Third Molars During Orthodontic Treatment.

Objective： To evaluate apical root resorption following active orthodontic treatment in subjects with impacted mandibular third molar.Methods： Ten orthodontic patients（8 female,2 male,aged 15 to 32 years） were selected with missing mandibular first molar and impacted mandibular third molars.They were uprighted through light wire and coiling spring.Panoramic radiographs were taken before and after treatment.The data was analyzed by SPSS statistical package.Results： All cases were uprighted.In adult group,apical root resorption was detected,but no differences was found.In adolescent group,the root length increased significantly（P0.05）.Conclusion： The results showed that the method was practical and reliable for correcting impacted mandibular molars.