Armond A C V, Martins C C, Glória J C R, Galvão E L, Dos Santos C R R, Falci S G M
Department of Dentistry, Universidade Federal dos Vales do Jequitinhona e Mucuri (UFVJM), Diamantina, MG, Brazil.
Department of Paediatric Dentistry and Orthodontics, School of Dentistry, Universidade Federal de Minas Gerais (UFMG), Pampulha, Belo Horizonte, MG, Brazil.
Int J Oral Maxillofac Surg. 2017 Jun;46(6):716-729. doi: 10.1016/j.ijom.2017.02.1264. Epub 2017 Mar 11.
The aim of this systematic review was to investigate the influence of the presence and position of mandibular third molars on angle fractures. An electronic search was conducted in the PubMed, Scopus, Web of Science, Cochrane Library, and VHL databases, through January 2016. The eligibility criteria included observational studies. The search strategy resulted in 704 articles. Following the selection process, 35 studies were included in the systematic review and 28 in the meta-analysis. Twenty studies presented a score of ≤6 stars in the Newcastle-Ottawa scale assessment, indicating a risk of bias in the analysis. The presence of a mandibular third molar increases the chance of an angle fracture (case-control and cross-sectional studies: odds ratio (OR) 3.83, 95% confidence interval (CI) 3.02-4.85, I=83.1%; case-control studies: OR 3.27, 95% CI 2.57-4.16, I=81.3%). The third molar positions most favourable to angle fracture according to the Pell and Gregory classification are class B (OR 1.44, 95% CI 1.06-1.96, I=87.2%) and class II (OR 1.67, 95% CI 1.36-2.04, I=72.4%). Class A (OR 0.60, 95% CI 0.45-0.81, I=87.1%) and class I (OR 0.51, 95% CI 0.37-0.71, I=89.4%) act as protective factors for angle fracture. The results suggest that the presence of the third molar increases the chance of angle fracture by 3.27 times and that the most favourable positions of the third molar for angle fracture are classes B and II, whilst classes A and I act as protective factors.
本系统评价的目的是研究下颌第三磨牙的存在及位置对角部骨折的影响。截至2016年1月，在PubMed、Scopus、Web of Science、Cochrane图书馆和VHL数据库中进行了电子检索。纳入标准包括观察性研究。检索策略共获得704篇文章。经过筛选过程，35项研究被纳入系统评价，28项被纳入荟萃分析。20项研究在纽卡斯尔-渥太华量表评估中得分为≤6星，表明分析存在偏倚风险。下颌第三磨牙的存在增加了角部骨折的几率（病例对照研究和横断面研究：比值比（OR）3.83，95%置信区间（CI）3.02 - 4.85，I = 83.1%；病例对照研究：OR 3.27，95% CI 2.57 - 4.16，I = 81.3%）。根据佩尔和格雷戈里分类，对角部骨折最有利的第三磨牙位置是B类（OR 1.44，95% CI 1.06 - 1.96，I = 87.2%）和II类（OR 1.67，95% CI 1.36 - 2.04，I = 72.4%）。A类（OR 0.60，95% CI 0.45 - 0.81，I = 87.1%）和I类（OR 0.51，95% CI 0.37 - 0.71，I = 89.4%）对角部骨折起到保护作用。结果表明，第三磨牙的存在使角部骨折的几率增加3.27倍，对角部骨折最有利的第三磨牙位置是B类和II类，而A类和I类起到保护作用。
