Alyammahi Ameirah Saeed, Kaklamanos Eleftherios G, Athanasiou Athanasios E
Hamdan Bin Mohammed College of Dental Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates.
Eur J Orthod. 2018 Apr 6;40(2):149-156. doi: 10.1093/ejo/cjx042.
Although extraction of primary canines in the mixed dentition has been suggested as a measure to prevent impaction of palatally displaced permanent canines (PDCs), the relevant evidence has been inconclusive.
To assess the effectiveness of this practice and investigate the quality of the evidence.
Search without restrictions in 15 databases and hand searching until April 2017.
Randomized clinical trials comparing extraction of primary canines in the mixed dentition to no treatment.
Following study retrieval and selection, data extraction, and individual study risk of bias assessment using the Cochrane Risk of Bias Tool, the random effects method of combining treatment effects was used. The overall quality of the available evidence was assessed with the Grades of Recommendation, Assessment, Development, and Evaluation approach.
Finally 5 studies were identified involving 214 individuals, followed for up to 48 months post-intervention. Two studies were at low and the rest at high risk of bias. Although at the 12-month evaluation, extraction of the primary canine did not result in a statistically significant difference [risk ratio (RR): 1.537; 95% confidence interval (CI): 0.656-3.601, P = 0.323; 1 study, n = 67 individuals], beyond 12 months a benefit was noted (RR: 1.784; 95% CI: 1.376-2.314, P = 0.000; 5 studies, n = 214 individuals; I2 = 0%). Analysis of the studies at low risk of bias confirmed the above-mentioned result (RR: 1.713; 95% CI: 1.226-2.394, P = 0.002; 2 studies, n = 91 individuals; I2 = 0%; moderate quality evidence). No difference was observed regarding root resorption of adjacent permanent teeth (RR: 0.602; 95% CI: 0.277-1.308, P = 0.200; 1 study; n = 67 individuals; moderate quality evidence).
Extraction of primary canines in the mixed dentition may increase the chance of subsequent successful eruption of PDC in the long term. However, better study standardization is necessary.
尽管有人建议在混合牙列期拔除乳尖牙作为预防腭向错位恒牙尖牙（PDC）阻生的一种措施，但相关证据尚无定论。
评估这种做法的有效性并调查证据质量。
截至2017年4月，在15个数据库中进行无限制检索并手工检索。
比较混合牙列期拔除乳尖牙与未治疗的随机临床试验。
在进行研究检索、筛选、数据提取以及使用Cochrane偏倚风险工具对个体研究的偏倚风险进行评估之后，采用合并治疗效应的随机效应方法。使用推荐分级、评估、制定与评价方法对现有证据的总体质量进行评估。
最终确定了5项研究，涉及214名个体，干预后随访长达48个月。2项研究偏倚风险低，其余研究偏倚风险高。尽管在12个月评估时，拔除乳尖牙未产生统计学上的显著差异[风险比（RR）：1.537；95%置信区间（CI）：0.656 - 3.601，P = 0.323；1项研究，n = 67名个体]，但在12个月之后观察到了益处（RR：1.784；95% CI：1.376 - 2.314，P = 0.000；5项研究，n = 214名个体；I² = 0%）。对偏倚风险低的研究进行分析证实了上述结果（RR：1.713；95% CI：1.226 - 2.394，P = 0.002；2项研究，n = 91名个体；I² = 0%；中等质量证据）。在相邻恒牙的牙根吸收方面未观察到差异（RR：0.602；95% CI：0.277 - 1.308，P = 0.200；1项研究；n = 67名个体；中等质量证据）。
在混合牙列期拔除乳尖牙可能会增加PDC随后长期成功萌出的机会。然而，需要更好的研究标准化。
