Arezoo Jahanbin
1,2 
, Nadia Hasanzadeh
1,2* , Sara Khaki
1, Hooman Shafaee
1,21 Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
2 Department of Orthodontics, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran
Abstract
Background. Self-ligating brackets might be more efficient than conventional appliance systems during the initial alignment stage of orthodontic treatment due to reduced frictional resistance. This study aimed to compare the alignment efficiency and pain experience of Damon3 self-ligating and MBT pre-adjusted brackets in the initial alignment stage. Methods. In this randomized clinical trial, 30 patients aged 14‒20 years, who needed non-extraction treatment in both maxillary and mandibular arches, were randomly assigned to two groups; 15 patients were treated with MBT pre-adjusted brackets, and 15 patients received Damon3 self-ligating brackets, both with 0.022-in slots. Alginate impressions were taken at the start of treatment (T0) and four monthly visits (T1, T2, T3, and T4). Little’s irregularity index (LII) was used to assess the tooth displacements. The patients rated their pain experience immediately after the insertion of the archwire, 4 hours, 24 hours, 3 days, 7 days, and at each monthly visit using a visual analog scale (VAS). Results. The rate of upper dental alignment between T0 and T4 was significantly higher with the Damon3 compared to MBT brackets (P=0.015). Although significantly more changes in the lower LII scores were observed during the first three months with the Damon3 system, the rate of improvement in the irregularity of lower teeth over the 4-month period was not significantly different between the two groups (P=0.50). The patients’ pain experience was not significantly different between the bracket groups (P=0.29). Conclusion. During the four-month alignment stage, significantly more improvement in the upper dental irregularity was observed with self-ligating compared to conventional brackets. The bracket type had no effect on pain experience during the alignment stage.