Angle Orthod. 2021 Jul 1;91(4):441-448. doi: 10.2319/110620-916.1.
To compare canine retraction using NiTi closed coil springs vs elastomeric chains comprehensively in a split-mouth randomized controlled trial.
The canines in 64 quadrants were randomly retracted into the first premolar extraction spaces using NiTi closed coil springs or elastomeric chains, in the maxilla and mandible. The retraction force was 150 g. Cone beam computed tomography scans and study models were obtained before the start of canine retraction and 6 months later. The rate and total amount of canine retraction, canine rotation, tipping, and root resorption were evaluated. A visual analogue scale was used to evaluate patients' pain experience.
The two methods were statistically similar for dental changes, rate of canine retraction, and root resorption. However, patients reported significantly more days of pain with the elastomeric chain compared to the NiTi closed coil springs.
Within the constraints of the current study, using either NiTi closed coil springs or elastomeric chains as force delivery systems for canine retraction results in no significant difference in the rate of canine retraction, tipping, rotation, or root resorption. Pain experience during retraction using elastomeric chains is more significant yet needs further investigation.
在一项随机对照的分口研究中，综合比较镍钛拉簧和橡胶链用于犬牙后移的效果。
将 64 个象限的犬牙随机使用镍钛拉簧或橡胶链向后移入第一前磨牙拔牙间隙，上颌和下颌分别使用。后移力为 150g。在犬牙后移开始前和 6 个月后，获取锥形束 CT 扫描和研究模型。评估犬牙后移的速率和总量、犬牙旋转、倾斜和牙根吸收。使用视觉模拟评分评估患者的疼痛体验。
两种方法在牙齿变化、犬牙后移速率和牙根吸收方面统计学上相似。然而，与镍钛拉簧相比，患者报告使用橡胶链时疼痛天数明显更多。
在本研究的限制范围内，使用镍钛拉簧或橡胶链作为犬牙后移的力传递系统，在犬牙后移速率、倾斜、旋转或牙根吸收方面没有显著差异。使用橡胶链进行后移时的疼痛体验更明显，但需要进一步研究。
