Moradinejad Mehrnaz, Ghorani Nasim, Heidarpour Majid, Noori Meysam, Rakhshan Vahid
Department of Orthodontics, Faculty of Dentistry, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Orthodontist in Private Practice, Isfahan, Iran.
Dent Res J (Isfahan). 2021 Oct 21;18:81. eCollection 2021.
There is no clinical study on ceramic self-ligating brackets (SLBs). Therefore, this preliminary study was conducted for the first time to address its effects.
This split-mouth randomized trial was performed on 32 quadrants in 16 orthodontic patients needing extraction of maxillary premolars and distalization of canines. In each blinded patient, right/left sides were randomized into control (ceramic bracket) and experimental (ceramic SLB) groups. Dental stone models were taken before canine retraction and 3 months into retraction. Models were digitized as three-dimensional models. Changes were measured on superimposed models. Groups were compared using Wilcoxon signed-rank test (α = 0.05, β = 0.1).
Both bracket types caused significant changes after 3 months in terms of all assessed clinical outcomes ( ≤ 0.002). Compared to conventional ceramic brackets (control), ceramic SLBs reduced retraction rate ( = 0.001), canine rotation ( = 0.001), canine tipping ( = 0.002), and arch expansion at the canine site ( = 0.003). However, the extents of anchorage loss ( = 0.796) and arch constriction in the premolar area ( = 0.605) were not statistically different between the bracket types.
Compared to conventional metal-lined ceramic brackets, active ceramic SLB can increase the duration of canine distalization, while reducing canine rotation and tipping (inducing more bodily movements). The loss of anchorage with ceramic SLB was similar to that of conventional ceramic bracket after 3 months of treatment (considering the lower rate of SLB canine retraction during that time). Both brackets similarly constricted the arch at the premolar site. In the canine area, they expanded the arch, with the SLB causing smaller extents of expansion.
目前尚无关于陶瓷自锁托槽（SLB）的临床研究。因此，首次开展了这项初步研究以探讨其效果。
本双盲随机试验针对16名需要拔除上颌前磨牙并远中移动尖牙的正畸患者的32个象限进行。在每位盲法患者中，右侧/左侧随机分为对照组（陶瓷托槽）和试验组（陶瓷自锁托槽）。在尖牙后移前及后移3个月时制取石膏模型。将模型数字化为三维模型。在叠加模型上测量变化。采用Wilcoxon符号秩检验进行组间比较（α = 0.05，β = 0.1）。
3个月后，两种托槽类型在所有评估的临床指标方面均引起了显著变化（P≤0.002）。与传统陶瓷托槽（对照组）相比，陶瓷自锁托槽降低了后移速率（P = 0.001）、尖牙旋转（P = 0.001）、尖牙倾斜（P = 0.002）以及尖牙部位的牙弓扩展（P = 0.003）。然而，两种托槽类型在支抗丧失程度（P = 0.796）和前磨牙区牙弓缩窄方面（P = 0.605）无统计学差异。
与传统金属内衬陶瓷托槽相比，主动式陶瓷自锁托槽可增加尖牙远中移动的时间，同时减少尖牙旋转和倾斜（诱导更多的整体移动）。治疗3个月后，陶瓷自锁托槽的支抗丧失与传统陶瓷托槽相似（考虑到在此期间自锁托槽尖牙后移速率较低）。两种托槽在前磨牙部位对牙弓的缩窄作用相似。在尖牙区域，它们均使牙弓扩展，自锁托槽导致的扩展程度较小。
