Abstract：
BACKGROUND: The objective was to provide a synthesis of the existing literature on the effectiveness of maxillary expansion in intercepting palatally displaced canines (PDCs).
METHODS: Studies that evaluated the effectiveness of maxillary expansion in subjects with PDCs in the mixed dentition period were included. The following electronic databases were searched until November 30, 2021: MEDLINE (via PubMed), Scopus, Google Scholar, Web of Science, and Cochrane library. Grey literature search and manual search were also performed. The risk of bias was assessed using the Cochrane tool for the one randomized controlled trial (RCT) and the ROBINS-I tool for the non-RCTs. The data were extracted and meta-analysis was performed using RevMan 5.4. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to assess the certainty of evidence.
RESULTS: Four studies were selected from 9,586 records, which included one RCT and three non-RCTs. The former demonstrated a high risk of bias whereas the non-RCTs showed moderate risk. The meta-analysis of three non-RCTs found no significant improvement in the alpha angle of canines after rapid maxillary expansion, with a difference of -4.26 (95% CI -11.41 to 2.89; P = 0.24). The RCT showed an increase in the eruption rate of high-risk canines with rapid maxillary expansion. Slow maxillary expansion did not demonstrate any favorable change. The level of evidence ranged from low to very low.
CONCLUSIONS: There is insufficient evidence to recommend the use of maxillary expansion as a stand-alone procedure in intercepting PDCs. Additional well-conducted trials are required.
METHODS: Studies that evaluated the effectiveness of maxillary expansion in subjects with PDCs in the mixed dentition period were included. The following electronic databases were searched until November 30, 2021: MEDLINE (via PubMed), Scopus, Google Scholar, Web of Science, and Cochrane library. Grey literature search and manual search were also performed. The risk of bias was assessed using the Cochrane tool for the one randomized controlled trial (RCT) and the ROBINS-I tool for the non-RCTs. The data were extracted and meta-analysis was performed using RevMan 5.4. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach was used to assess the certainty of evidence.
RESULTS: Four studies were selected from 9,586 records, which included one RCT and three non-RCTs. The former demonstrated a high risk of bias whereas the non-RCTs showed moderate risk. The meta-analysis of three non-RCTs found no significant improvement in the alpha angle of canines after rapid maxillary expansion, with a difference of -4.26 (95% CI -11.41 to 2.89; P = 0.24). The RCT showed an increase in the eruption rate of high-risk canines with rapid maxillary expansion. Slow maxillary expansion did not demonstrate any favorable change. The level of evidence ranged from low to very low.
CONCLUSIONS: There is insufficient evidence to recommend the use of maxillary expansion as a stand-alone procedure in intercepting PDCs. Additional well-conducted trials are required.
摘要：
背景：目的是提供有关上颌扩张在截获腭移位犬（PDC）中的有效性的现有文献的综合。
方法：包括评估混合牙列期PDCs受试者上颌扩张效果的研究。在2021年11月30日之前搜索了以下电子数据库：MEDLINE（通过PubMed），Scopus,谷歌学者，WebofScience,科克伦图书馆还进行了灰色文献检索和手动检索。在一项随机对照试验（RCT）中使用Cochrane工具和在非RCT中使用ROBINS-I工具评估偏倚风险。提取数据并使用RevMan5.4进行荟萃分析。建议的分级，评估,使用开发和评估(GRADE)方法来评估证据的确定性。
结果：从9,586条记录中选择了四项研究，其中包括1个RCT和3个非RCT。前者表现出高风险的偏倚，而非RCT表现出中等风险。三个非RCT的荟萃分析发现，快速上颌扩张后犬齿的α角没有明显改善，差异为-4.26(95%CI-11.41~2.89；P=0.24)。RCT显示，上颌快速扩张的高风险犬的喷发率增加。上颌缓慢扩张没有显示出任何有利的变化。证据水平从低到非常低。
结论：没有足够的证据推荐使用上颌扩张作为拦截PDC的独立程序。需要进行其他良好的试验。
方法：包括评估混合牙列期PDCs受试者上颌扩张效果的研究。在2021年11月30日之前搜索了以下电子数据库：MEDLINE（通过PubMed），Scopus,谷歌学者，WebofScience,科克伦图书馆还进行了灰色文献检索和手动检索。在一项随机对照试验（RCT）中使用Cochrane工具和在非RCT中使用ROBINS-I工具评估偏倚风险。提取数据并使用RevMan5.4进行荟萃分析。建议的分级，评估,使用开发和评估(GRADE)方法来评估证据的确定性。
结果：从9,586条记录中选择了四项研究，其中包括1个RCT和3个非RCT。前者表现出高风险的偏倚，而非RCT表现出中等风险。三个非RCT的荟萃分析发现，快速上颌扩张后犬齿的α角没有明显改善，差异为-4.26(95%CI-11.41~2.89；P=0.24)。RCT显示，上颌快速扩张的高风险犬的喷发率增加。上颌缓慢扩张没有显示出任何有利的变化。证据水平从低到非常低。
结论：没有足够的证据推荐使用上颌扩张作为拦截PDC的独立程序。需要进行其他良好的试验。
