Adults with fixed orthodontic appliances are increasing nowadays. Compared with adolescents, adults present biological differences that might influence treatment duration. Therefore, the aim of the study was to compare duration of treatment with fixed appliances between adults and adolescents. Eight databases were searched up to September 2019 for randomized and non-randomized clinical studies comparing treatment duration with fixed appliances in adolescents and adult patients. After duplicate study selection, data extraction, and risk of bias assessment with the Cochrane ROBINS-I tool, random effects meta-analyses of mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by assessment of the quality of evidence with GRADE. A total of 11 unique studies (one prospective and 10 retrospective non-randomized) with 2969 adolescents and 1380 adult patients were finally included. Meta-analysis of 7 studies found no significant difference in the duration of comprehensive treatment with fixed appliances (MD = − 0.8 month; 95% CI = − 4.2 to 2.6 months; P = 0.65; I2 = 92%) between adults and adolescents. Similarly, both distalization of upper first molars with skeletal anchorage for class II correction and the retraction of canines into the premolar extraction spaces lasted similarly long among adults and adolescents. On the other hand, alignment of palatally displaced canines lasted considerably longer in adults compared to adolescents (1 study; MD = 3.8 months; 95% CI = 1.4 to 6.2 months; P = 0.002). The quality of evidence for the meta-analysis was low due to the inclusion of non-randomized studies with considerable risk of bias. While existing evidence does not indicate a difference in the overall duration of treatment with fixed appliances between adults and adolescents, the alignment of palatally displaced canines lasted significantly longer in adults. However, our confidence in these estimates is low due to the risk of bias in the included studies. PROSPERO: ( CRD42019148169 )

中文翻译：

---

青少年和成人固定矫治器正畸治疗的持续时间：荟萃分析的系统评价


如今，拥有固定正畸矫治器的成年人越来越多。与青少年相比，成年人存在可能影响治疗持续时间的生物学差异。因此，该研究的目的是比较成人和青少年固定矫治器的治疗持续时间。截至 2019 年 9 月，我们检索了八个数据库，以比较青少年和成年患者使用固定矫治器的治疗持续时间的随机和非随机临床研究。在重复研究选择、数据提取和使用 Cochrane ROBINS-I 工具进行偏倚风险评估后，对平均差 (MD) 及其 95% 置信区间 (CI) 进行随机效应荟萃分析，然后进行质量评估证据的等级。最终纳入了 11 项独特研究（一项前瞻性研究和 10 项回顾性非随机研究），涉及 2969 名青少年和 1380 名成年患者。对 7 项研究的荟萃分析发现，成人和青少年之间固定矫治器综合治疗的持续时间没有显着差异（MD = − 0.8 个月；95% CI = − 4.2 至 2.6 个月；P = 0.65；I2 = 92%）。同样，在成人和青少年中，使用骨骼支抗进行 II 级矫正的上第一磨牙远移和尖牙回缩至前磨牙拔牙空间的持续时间相似。另一方面，与青少年相比，成年人上颌移位犬齿的排列持续时间要长得多（一项研究；MD = 3.8 个月；95% CI = 1.4 至 6.2 个月；P = 0.002）。由于纳入了具有相当大偏倚风险的非随机研究，荟萃分析的证据质量较低。 虽然现有证据并未表明成人和青少年之间使用固定矫治器治疗的总持续时间存在差异，但上颌移位犬齿的排列在成人中持续的时间明显更长。然而，由于纳入的研究存在偏倚风险，我们对这些估计的信心较低。普洛斯彼罗：（CRD42019148169）