Comparison of the initial levelling efficiency of two different self-ligating brackets

Aim: The objective of this study, to evaluate the initial alignment effectiveness of two different passive self-ligating brackets (SLBs) and to compare the differences in arch widths. Materials and Methods: The patients with no skeletal discrepancy, Little’s irregularity index (LII) greater than 3 mm on both arches, who were treated with SLBs and whom had undamaged plaster models at the beginning (T0), 10th week (T1), and 20th week (T2) of their treatment period were enrolled to the study group. Group 1 (Damon) was consisted of 17 patients (mean age=14.5 years) and Group 2 (SmartClip) was consisted of 18 patients (mean age=13.6 years). The analogue dental casts were transferred to a digital model by scanning. Maxillary and mandibular intercanine, intermolar widths and LII were measured by MeshLab software. Wilcoxon signed-rank and Mann Whitney U tests was used for statistical evaluation. Results: There were no significant differences between the groups for the mean LII in T0 (maxillary LII, Group 1= 6.59 mm; Group 2= 6.32 mm; mandibular LII, Group 1= 5.95 mm, Group 2= 5.73mm). The rate of decrease in the LII between T0-T2 and between T1-T2 were found to be significantly higher for Group 1 in the mandible but there was no significant difference between T0-T1 (P= 0.031, P= 0.042, P= 0.113). There was no significant difference for the rate of decrease in the LIIs between the groups in the maxilla. When changes of intermolar and intercanine widths were compared according to the follow-up times, no significant differences were found for the treatment groups. Conclusion: Both SLBs groups were effective for reducing the crowding in maxillary arch. The increases in intercanine and intermolar widths were found to be similar for both groups. Group 1 was found to be better in the speed of the resolution of the crowding only in the lower incisor region