Department of Orthodontics, Faculty of Dentistry, Oral and Craniofacial Sciences, Centre for Craniofacial Development and Regeneration, King's College London, London, United Kingdom.
Department of Mucosal Biology, Faculty of Dentistry, Oral and Craniofacial Sciences, Centre for Host Disease, King's College London, London, United Kingdom.
Am J Orthod Dentofacial Orthop. 2022 Jan;161(1):20-36. doi: 10.1016/j.ajodo.2021.06.016. Epub 2021 Nov 16.
A key goal of orthodontic treatment with fixed appliances is alignment of the dentition, and this remains a commonly selected outcome in clinical studies investigating orthodontic tooth movement. This systematic review has evaluated treatment duration to achieve alignment of the mandibular dentition using fixed appliances.
Systematic literature searches without restrictions were undertaken in 9 databases for randomized clinical trials (RCTs) assessing duration and rate of tooth alignment using fixed appliances with or without treatment adjuncts published up to January 2021. After duplicate study selection, data extraction, and risk of bias assessment according to Cochrane, random-effects meta-analyses of aggregate data, and individual patient data were conducted.
Thirty-five trials were included with 2258 participants (39% male; mean age 17.8 years), giving a pooled duration to achieve whole-arch alignment of the mandibular dentition of 263.0 days (4 trials; 95% confidence interval [CI], 186.7-339.4 days) and incisor alignment in the mandibular arch of 100.7 days (9 trials; 95% CI, 84.1-117.4 days). Surgical-assisted orthodontics was associated with reduced duration of incisor alignment: mean difference of 44.3 days less (4 trials; 95% CI, 20.0-68.9 days; P <0.001; high quality of evidence), whereas subgroup and meta-regression analyses indicated significant effects of baseline crowding and premolar extractions. Individual patient data analysis from 3 RCTs indicated that for each additional participant age year, whole-arch alignment of the mandibular dentition took 13.7 days longer (3 trials; 95% CI, 7.7-17.7 days; P <0.001) and for each additional mm of irregularity, 17.5 days more were needed (2 trials; 95% CI, 9.8-25.2 days; P <0.001).
Patient and treatment-related characteristics can significantly affect the duration of tooth alignment and should be taken into account both clinically and when designing trial outcomes. Future research studies investigating rates of orthodontic tooth alignment would benefit from adequate sample sizes and a more consistent methodology in outcome assessment. Data in this systematic review provides a basis for appropriate trial design for future RCTs investigating the rate of orthodontic tooth alignment with fixed appliances.
正畸治疗的一个关键目标是排齐牙齿，这仍然是研究正畸牙齿移动的临床研究中常用的选择结果。本系统评价评估了使用固定矫治器排齐下颌牙齿的治疗持续时间。
系统检索了 9 个数据库，检索了截至 2021 年 1 月评估使用固定矫治器联合或不联合治疗辅助装置治疗时牙齿对齐所需时间和速率的随机临床试验（RCT）。根据 Cochrane 进行重复研究选择、数据提取和偏倚风险评估后，进行了汇总数据和个体患者数据的随机效应荟萃分析。
共纳入 35 项试验，共 2258 名参与者（39%为男性；平均年龄 17.8 岁），整体下颌牙列排齐的治疗持续时间为 263.0 天（4 项试验；95%置信区间 [CI]，186.7-339.4 天），下颌牙弓切牙排齐时间为 100.7 天（9 项试验；95%CI，84.1-117.4 天）。辅助正畸手术可缩短切牙排齐时间：平均少 44.3 天（4 项试验；95%CI，20.0-68.9 天；P<0.001；高质量证据），而亚组和荟萃回归分析表明基线拥挤度和前磨牙拔牙有显著影响。3 项 RCT 的个体患者数据分析表明，每增加 1 岁的参与者年龄，下颌牙列的整体排齐时间增加 13.7 天（3 项试验；95%CI，7.7-17.7 天；P<0.001），每增加 1 毫米的不规则度，需要增加 17.5 天（2 项试验；95%CI，9.8-25.2 天；P<0.001）。
患者和治疗相关特征会显著影响牙齿排齐的时间，在临床和设计试验结果时都应考虑到这些因素。未来研究正畸牙齿排齐速度的研究将受益于足够的样本量和更一致的结果评估方法。本系统评价中的数据为未来使用固定矫治器研究正畸牙齿排齐速度的 RCT 提供了适当的试验设计基础。
