Cheng Hsin-Chung, Peng Bou-Yue, Hsieh Hsueh-Yin, Tam Ka-Wai
School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan.
J Dent Sci. 2018 Mar;13(1):1-7. doi: 10.1016/j.jds.2017.10.005. Epub 2017 Dec 11.
BACKGROUND/PURPOSE: Whether third molars contribute to or aggravate relapse, particularly in the mandibular dental arch, after orthodontic treatment remains controversial. Orthodontic clinicians vary widely in their practice regarding prophylactic third molar removal after orthodontic treatment. The present study systematically reviewed and meta-analyzed the available literature, and assessed the impact of third molar removal on the relapse of mandibular dental arch alignment after orthodontic treatment.
Relevant literature was searched on online databases, namely Pubmed, Embase, and Cochrane. Outcomes of post-orthodontic mandibular relapse were evaluated in terms of the Little's irregularity index, intermolar width, and arch length. Statistical analysis was conducted using the Review Manager software (Version 5.3, The Cochrane Collaboration, Oxford, England).
Our initial search strategy yielded 360 citations, of which three retrospective studies were selected. The Little's irregularity index (weighted mean difference = 0.80, 95% confidence interval = 0.13-1.47, P = 0.02) differed significantly between the erupted third molar extraction group and agenesis third molar group; whereas the arch length and intermolar width did not. No outcome differed significantly between the impacted third molar extraction group and agenesis third molar group.
Removal of the mandibular third molars is recommended for alleviating or preventing long-term incisor irregularity.
背景/目的：正畸治疗后，第三磨牙是否会导致或加重复发，尤其是在下颌牙弓，仍存在争议。正畸临床医生在正畸治疗后预防性拔除第三磨牙的实践中差异很大。本研究系统回顾并荟萃分析了现有文献，评估了拔除第三磨牙对正畸治疗后下颌牙弓排列复发的影响。
在在线数据库，即PubMed、Embase和Cochrane上搜索相关文献。根据利特尔不规则指数、磨牙间宽度和牙弓长度评估正畸后下颌复发的结果。使用Review Manager软件（版本5.3，Cochrane协作网，英国牛津）进行统计分析。
我们最初的检索策略产生了360条引文，其中选择了三项回顾性研究。萌出第三磨牙拔除组和第三磨牙先天缺失组之间的利特尔不规则指数（加权平均差=0.80，95%置信区间=0.13-1.47，P=0.02）有显著差异；而牙弓长度和磨牙间宽度没有差异。阻生第三磨牙拔除组和第三磨牙先天缺失组之间的任何结果均无显著差异。
建议拔除下颌第三磨牙以减轻或预防长期的切牙不规则。
