Department of Orthodontics, University of Malmö, Malmö, Sweden.
Orthod Craniofac Res. 2013 May;16(2):105-15. doi: 10.1111/ocr.12011. Epub 2013 Jan 3.
To evaluate three different retention methods in compliant patients after 2 years of retention.
Three group randomized controlled trial.
The sample was recruited from patients having their fixed appliance treatment between 2001 and 2007. Seventy-five patients (45 girls and 30 boys with a mean age of 14.4 years at start of retention) were randomized into three retention methods: vacuum-formed retainer in the maxilla and bonded canine-to-canine retainer in the mandible (Group V-CTC), vacuum-formed retainer in the maxilla combined with stripping of the 10 proximal surfaces of the lower mandibular anterior teeth (Group V-S) and prefabricated positioner covering the teeth in the maxilla and the mandible (Group P). The following linear measurements were performed: Little's irregularity index (LII), intercanine width, intermolar width, arch length, overjet, overbite and body height growth. Registrations were made before orthodontic treatment, at start of retention, after 12 and finally 24 months in retention. Differences in means between groups were tested by one-way analysis of variance (SPSS).
After 2 years all three retention methods were successful in retaining orthodontic treatment results. The major part of relapse took place during the 1st year of retention.
All 3 types of retention methods were equally effective in controlling relapse to a clinically acceptable level.
评价依从性患者在 2 年保持期后的 3 种不同保持方法。
三组随机对照试验。
样本来自于 2001 年至 2007 年接受固定矫正治疗的患者。75 名患者（45 名女孩和 30 名男孩，起始保持时的平均年龄为 14.4 岁）被随机分为 3 种保持方法：上颌的真空成形保持器和下颌的粘结尖牙-尖牙保持器（V-CTC 组）、上颌的真空成形保持器结合下颌前牙 10 个近中面的剥离（V-S 组）和覆盖上颌和下颌牙齿的预制定位器（P 组）。进行了以下线性测量：Little 不调指数（LII）、尖牙间宽度、磨牙间宽度、牙弓长度、覆颌、覆盖和体高生长。在正畸治疗前、保持开始时、12 个月后和 24 个月后进行登记。通过单因素方差分析（SPSS）检验组间均值的差异。
2 年后，所有 3 种保持方法均成功保持了正畸治疗效果。大部分复发发生在保持的第 1 年。
所有 3 种保持方法在控制复发至临床可接受水平方面均同样有效。
