Khanemasjedi Mashallah, Moradinejad Mehrnaz, Javidi Pedram, Niknam Ozra, Jahromi Nima Haghighat, Rakhshan Vahid
Department of Orthodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Iranian Tissue Engineering and Graft Research Center, Tehran University of Medical Sciences, Tehran, Iran.
Int Orthod. 2017 Dec;15(4):561-574. doi: 10.1016/j.ortho.2017.09.011. Epub 2017 Nov 16.
The use of newly-introduced elastic memory chains (EMCs) in space closure is increasingly gaining popularity. However, no clinical studies have evaluated their efficacy. Therefore, this study was conducted.
In this two-center split-mouth single-blind randomized controlled trial, 21 jaws were divided into 42 quadrants. The two treatments [canine retraction using EMCs versus nickel-titanium (NiTi) coil springs (as control)] were randomly assigned to two quadrants of each jaw. The premolar space was measured at the baseline, and in the 1st, 2nd, and 3rd months of canine retraction, by a blinded orthodontist. Space closure rates were compared using a paired t-test.
The rates of space closure using NiTi springs were 1.93±0.62, 1.71±0.75, and 1.36±0.51mm/month, during the 1st, 2nd, and 3rd months of treatment, respectively. The 3-month average rates of space closure were 1.67±0.39 and 1.89±0.36mm/month in the NiTi and elastic groups, respectively (faster in the elastic group, P=0.022).
The application of elastic memory chains is as effective as NiTi springs.
新引入的弹性记忆链（EMC）在间隙关闭中的应用越来越普遍。然而，尚无临床研究评估其疗效。因此，开展了本研究。
在这项双中心、分口、单盲随机对照试验中，将21例颌骨分为42个象限。两种治疗方法[使用EMC牵引尖牙与使用镍钛（NiTi）螺旋弹簧（作为对照）]被随机分配至每例颌骨的两个象限。由一名盲法正畸医生在基线时以及尖牙牵引的第1、2和3个月测量前磨牙间隙。使用配对t检验比较间隙关闭率。
在治疗的第1、2和3个月，使用NiTi弹簧的间隙关闭率分别为1.93±0.62、1.71±0.75和1.36±0.51mm/月。NiTi组和弹性组的3个月平均间隙关闭率分别为1.67±0.39和1.89±0.36mm/月（弹性组更快，P = 0.022）。
弹性记忆链的应用与NiTi弹簧一样有效。
