目的：评价不同下颌前伸度的口腔矫治器治疗阻塞性睡眠呼吸暂停低通气综合征（obstructive sleep apnea and hyponea syndrome，OSAHS）的临床疗效。方法： 计算机检索PubMed、Embase、Cochrane图书馆、CNKI、维普和万方等数据库，纳入不同下颌前伸度的口腔矫治器治疗OSAHS的随机对照试验（randomized clinical trials，RCT）和前后对照试验（before-after trials，BAT），对其进行质量评价并提取资料，用RevMan 5.3软件进行meta分析。结果： 纳入2个RCT、2个采用了随机方法的BAT和3个非随机BAT，共244例患者。根据方法学质量评价及各试验设计情况，对其中4篇高质量研究进行meta分析，结果显示，下颌前伸量达到下颌最大前伸度（maximal mandibular advancement，MMA）50%与75%两组的治疗有效率［呼吸暂停低通气指数（apnea hypopnea index，AHI）或氧减指数（oxygen desaturation index，ODI)降低>50%］比较，I2=0%，合并效应量RR值为0.93， 95%CI为0.80~1.09；两组的治愈率（AHI或ODI<10次/h）比较，I2=45%，合并效应量RR值为0.85， 95%CI为0.68~1.06，证据尚不足以证明两组的治疗有效率和治愈率有差异。亚组分析提示病情严重程度可能是影响治愈率的重要因素。结论： 对于OSAHS患者，在一定范围内下颌前伸度增加有利于提高治疗有效率和治愈率，但尚缺乏足够证据证明75%MMA优于50%MMA;轻症患者治愈率高于重症。

Objective： To evaluate the polysomnology results along with mandibular titrated advancement using oral appliance to treat obstructive sleep apnea and hyponea syndrome(OSAHS). Methods: Several electronic databases (PubMed, Embase, Cochrane Library, CNKI, VIP, and Wanfang) were systematically searched up to September 2015.There was no restriction of language or source of information. All randomized clinical trials (RCT) and before-after trials (BAT) comparing at least two different mandibular advancements were included. Two independent reviewers selected the studies, extracted data and evaluated risk of bias by quality assessment. Data were pooled using a fixed-effects model, and the summary effect measure was calculated by risk ratio (RR) and 95%CI. Meta-analysis was performed using RevMan 5.3 software. Results: Two RCTs and five BATs were included in the review. Among the five BATs, two of them were randomized, while the other three were not. Outcomes including apnea hypopnea index (AHI), oxygen desaturation index (ODI), success rate (reduction of AHI or ODI >50%), normalization rate (AHI or ODI<10/h) were assessed in this review. Based on the trial design and quality assessment, four studies were included for meta-analysis. No significant difference in the success rate was found between the group with 50% of the maximal mandibular advancement (MMA) and the group with 75% of MMA ［I2=0%, RR=0.93, with 95%CI (0.80, 1.09)］. No significant dif-ference in the normalization rate was found between the 50% of MMA and 75% of MMA groups ［I2=45%, RR=0.85, with 95%CI (0.68, 1.06)］. Subgroup analysis displayed that the severity of OSAHS before treatment was a potential factor affecting the normalization rate. Conclusion: Based on current available evidence, the success rate and normalization rate for treating OSAHS in the patients with 75% MMA were not found to be significantly higher than those with 50% MMA. Due to small simple size in this meta-analysis, the results of the present study should be interpreted with caution. Further prospective studies are needed to strengthen the evidence.