中文摘要：

目的：系统评价Twin-block矫治器对安氏Ⅱ类1分类青少年患者颌骨及牙齿的矫治效果。方法：检索Cochrane图书馆、Pub Med、Embase、Ovid Medline、Web of Science、CNKI、万方数据库、维普数据库、中国生物医学文献数据库中关于Twin-block矫治器治疗安氏Ⅱ类1分类错牙合畸形的随机对照试验或病例对照研究,并对纳入研究的质量进行评价。对纳入文献中治疗前后头影测量指标的变化进行Meta分析。结果：共纳入7项研究。Meta分析结果显示：与自然生长对照组相比,经过Twin-block矫治器治疗后的患者ANB、SNA、OJ、OB、U1-Max和U1-S vertical减小,SNB、Co-Pg、Go-Me、Ar-Go、LFH、L1-Man、L1-S vertical增大,差异均有统计学意义。SNA、CoPg、OJ、OB、U1-Max、U1-S vertical、L1-Man、L1-S vertical存在发表偏倚和异质性。GRADE系统质量评估显示SNB、Go-Me、Ar-Go、ANB、LFH为中等证据,OJ、U1-Max、U1-S vertical、L1-Mand、L1-S vertical为低等级证据,SNA、OB、Co-Pg为极低等级证据。结论：Twin-block矫治器对青少年安氏Ⅱ类1分类错牙合的矫正主要是通过牙齿的移动完成,颌骨只发生了轻度的改变。仍需开展更多高质量、大样本、多中心的随机对照试验进一步研究。

英文摘要：

Objective To evaluate the treatment effects of Twin-block appliances on class Ⅱ division 1 malocclusions in ad- olescence.Methods The databases including Cochrane Library, PubMed, Embase, Ovid Medline, Web of Science, CNKI, VIP, Wanfang Data and CBM were searched for randomized controlled trials or case-controlled trials about Twin-block ap- pliances applied to treat class Ⅱ division 1 malocclusions.The quality of enrolled studies were evaluated, and then recta-a- nalysis were performed on the indexes changes of cephalometric.Results Seven studies were identified.The results of meta- analysis showed that the indexes of ANB, SNA, O J, OB, U1-Max and U1-S vertical had significantly decreased,but SNB, Co -Pg, Go-Me, Ar-Go, LFH, LI-Man, and L1 -S vertical had increased in patients of twin-block group compared with control group.Publication bias and heterogeneity were detected in SNA, Co-Pg, OJ, OB, U1-Max, U 1-S vertical, LI-Man and LI- S vertical. Evidence quality analysis showed that the quality of SNB, Go-Me, Ar-Go, ANB, and LFH were moderate, O J, U 1- Max, U1-S vertical, L1-Mand and L1-S vertical were low,whereas SNA, OB and Co-Pg were even lower.Conclusion Cor- recting class Ⅱ division I malocclusion using Twin-block appliances during adolescence is accomplished mainly through dental movements.Skeletal changes is slight. More large-sample randomized controlled trails using unified digital cephalo- metric analysis are required.