The Rate of Mandibular Incisor Initial Alignment and Occlusal Dimensional Changes: A Comparison between Conventional and Self-Ligating Brackets

Introduction: Self-ligating brackets (SLBs) are considered to have several advantages over conventional brackets (CBs). However some of their strengths lack support by strong clinical studies.

Aim: To compare the rate of mandibular incisor initial alignment and occlusal dimensional changes among none-extraction patients treated with conventional (Victory Series) and self-ligating (SmartClip) brackets.

Material and Methods: Fifty-seven patients (30 SLB and 27 CB) were enrolled to investigate the rate of incisors alignment and occlusal dimensional changes. The Little irregularity index measured on dental models used to quantify the amount of dental discrepancy before (T1) and after (T2) alignment of the anterior dentition. The time taken to align the irregularity was as well measured to determine the rate of teeth alignment. In addition, the inter-canines and inter-molars distances were measured on dental models at T1 and T2 to assess the arch dimension changes.

Results: The total mean (maxillary and Mandibular) discrepancies reductions were 6.66-mm (SLB) and 8.04-mm (CB). Whereas, the time used for incisors alignment by SLB and CB groups were 93.48 and 93.38 days respectively. The occlusal changes and rate of. The mean Little’s index reduction (mm/month) was 2.05 for SLB and 2.43 for CB groups. The difference was not statistically significant (P = 0.216).

Conclusion: The rate of incisors alignment was not influenced by the type of bracket used. The alignment significantly increased the inter-canine and inter-molar distances except for maxillary inter-canines distance; however the arch dimension measurements were independent of the bracket systems used.

Keywords: Orthodontics, Self-ligating brackets, Dental alignment, Inter-canine distance, Inter-molar distance.