Abstract：
Orthodontic space closure of extraction sites can be initiated early, within 1-week post-extraction, or it can be delayed for a month or more.
This systematic review aimed to evaluate the effect of early versus delayed initiation of space closure after tooth extraction on the rate of orthodontic tooth movement.
Unrestricted search of 10 electronic databases was conducted until September 2022.
Randomized controlled trials (RCTs) investigating the initiation time of space closure of extraction sites in patients undergoing orthodontic treatment were included.
Data items were extracted using a pre-piloted extraction form. The Cochrane\'s risk of bias tool (ROB 2.0) and the Grading of Recommendations, Assessment, Development, and Evaluation approach were used for quality assessment. Meta-analysis was undertaken if there are at least two trials reporting the same outcome.
Eleven RCTs met the inclusion criteria. Meta-analysis revealed that early canine retraction resulted in a statistically significant higher rate of maxillary canine retraction when compared to delayed canine retraction [mean difference (MD); 0.17 mm/month, 95% CI: 0.06 to 0.28, P = 0.003, 4 RCTs, moderate quality]. Duration of space closure was shorter in the early space closure group, but not statistically significant (MD; 1.11 months, 95% CI: -0.27 to 2.49, P = 0.11, 2 RCTs, low quality). The incidence of gingival invaginations was not statistically different between early and delayed space closure groups (Odds ratio; 0.79, 95% CI: 0.27 to 2.29, 2 RCTs, P = 0.66, very low quality). Qualitative synthesis found no statistically significant differences between the two groups regarding anchorage loss, root resorption, tooth tipping, and alveolar bone height.
Based on the available evidence, early traction within the first week after tooth extraction has a minimal clinically significant effect on the rate of tooth movement compared to delayed traction. Further high-quality RCTs with standardized time points and measurement methods are still needed.
PROSPERO (CRD42022346026).
This systematic review aimed to evaluate the effect of early versus delayed initiation of space closure after tooth extraction on the rate of orthodontic tooth movement.
Unrestricted search of 10 electronic databases was conducted until September 2022.
Randomized controlled trials (RCTs) investigating the initiation time of space closure of extraction sites in patients undergoing orthodontic treatment were included.
Data items were extracted using a pre-piloted extraction form. The Cochrane\'s risk of bias tool (ROB 2.0) and the Grading of Recommendations, Assessment, Development, and Evaluation approach were used for quality assessment. Meta-analysis was undertaken if there are at least two trials reporting the same outcome.
Eleven RCTs met the inclusion criteria. Meta-analysis revealed that early canine retraction resulted in a statistically significant higher rate of maxillary canine retraction when compared to delayed canine retraction [mean difference (MD); 0.17 mm/month, 95% CI: 0.06 to 0.28, P = 0.003, 4 RCTs, moderate quality]. Duration of space closure was shorter in the early space closure group, but not statistically significant (MD; 1.11 months, 95% CI: -0.27 to 2.49, P = 0.11, 2 RCTs, low quality). The incidence of gingival invaginations was not statistically different between early and delayed space closure groups (Odds ratio; 0.79, 95% CI: 0.27 to 2.29, 2 RCTs, P = 0.66, very low quality). Qualitative synthesis found no statistically significant differences between the two groups regarding anchorage loss, root resorption, tooth tipping, and alveolar bone height.
Based on the available evidence, early traction within the first week after tooth extraction has a minimal clinically significant effect on the rate of tooth movement compared to delayed traction. Further high-quality RCTs with standardized time points and measurement methods are still needed.
PROSPERO (CRD42022346026).
摘要：
背景：拔牙部位的正畸间隙闭合可以早期开始，拔除后1周内，或者可以推迟一个月或更长时间。
目的：本系统综述旨在评估拔牙后早期和延迟开始间隙闭合对正畸牙齿移动率的影响。
方法：对10个电子数据库进行无限制搜索，直至2022年9月。
方法：包括研究正畸治疗患者拔牙部位空间闭合起始时间的随机对照试验（RCT）。
方法：使用预试点提取表提取数据项。Cochrane的偏见风险工具(ROB2.0)和建议分级，评估,发展,采用评价方法进行质量评价。如果至少有两个试验报告相同的结果，则进行荟萃分析。
结果：11项RCT符合纳入标准。荟萃分析显示，与延迟的犬退缩相比，早期的犬退缩导致上颌犬退缩率具有统计学意义的较高[平均差异（MD）；0.17毫米/月，95%CI：0.06至0.28，P=0.003，4个RCT，质量适中]。早期空间闭合组的空间闭合持续时间较短，但无统计学意义(MD；1.11个月，95%CI：-0.27至2.49，P=0.11，2个RCT，低质量)。早期和延迟间隙闭合组之间牙龈内陷的发生率没有统计学差异（赔率；0.79，95％CI：0.27至2.29，2个随机对照试验，P=0.66，质量很低）。定性综合发现两组之间关于锚固损失没有统计学上的显著差异，根吸收，牙齿倾斜,和牙槽骨高度。
结论：根据现有证据，与延迟牵引相比，拔牙后第一周内的早期牵引对牙齿移动速度的临床显着影响最小。仍然需要具有标准化时间点和测量方法的其他高质量RCT。
背景：PROSPERO（CRD42022346026）。
目的：本系统综述旨在评估拔牙后早期和延迟开始间隙闭合对正畸牙齿移动率的影响。
方法：对10个电子数据库进行无限制搜索，直至2022年9月。
方法：包括研究正畸治疗患者拔牙部位空间闭合起始时间的随机对照试验（RCT）。
方法：使用预试点提取表提取数据项。Cochrane的偏见风险工具(ROB2.0)和建议分级，评估,发展,采用评价方法进行质量评价。如果至少有两个试验报告相同的结果，则进行荟萃分析。
结果：11项RCT符合纳入标准。荟萃分析显示，与延迟的犬退缩相比，早期的犬退缩导致上颌犬退缩率具有统计学意义的较高[平均差异（MD）；0.17毫米/月，95%CI：0.06至0.28，P=0.003，4个RCT，质量适中]。早期空间闭合组的空间闭合持续时间较短，但无统计学意义(MD；1.11个月，95%CI：-0.27至2.49，P=0.11，2个RCT，低质量)。早期和延迟间隙闭合组之间牙龈内陷的发生率没有统计学差异（赔率；0.79，95％CI：0.27至2.29，2个随机对照试验，P=0.66，质量很低）。定性综合发现两组之间关于锚固损失没有统计学上的显著差异，根吸收，牙齿倾斜,和牙槽骨高度。
结论：根据现有证据，与延迟牵引相比，拔牙后第一周内的早期牵引对牙齿移动速度的临床显着影响最小。仍然需要具有标准化时间点和测量方法的其他高质量RCT。
背景：PROSPERO（CRD42022346026）。
