Changes in the lower dental arch in patients treated with conventional brackets and self-ligating brackets – a comparison

Abstract

Aim: The aim was to assess the changes in the mandible in patients treated with conventional brackets compared to those treated with self-ligating brackets. In particular, we focused on the degree of transversal changes and the length of therapy. Material and method: The sample included 43 patients; 11 men and 32 women. The mean age was 22.2 years. The patients had complete permanent dentition, were treated without extractions, molars in Angle Class I. The subjects were divided into two groups – conventional brackets, self-ligating brackets. Measurements were performed in scans of cast models made prior to therapy (T1), after removal of fixed appliance (T2), the length of treatment was given in months. The changes in intercanine and intermolar distance were compared in teeth and in relevant points on WALA ridge of the mandible. ORTODONCIE | ročník 33 | č. 2/2024 ODBORNÉ PRÁCE / ORGINAL ARTICLES 29 www.ortodonciejournal.cz | e-mail: redakce@ortodonciejournal.cz, office@ortodonciejournal.cz Results: In lower first molars the change in intermolar width was significant in both groups both at T1 and T2. The change was significantly bigger in the group with self-ligating brackets. The change in intercanine width between T2 and T1 was statistically significant only in the group with self-ligating brackets when measured on canine tips. Measurements at FA points (the most prominent point in the middle of longitudinal axis of the clinical crown) did not prove significant change. At WALA the change between T2 and T1 was significant only in the group with self-ligating brackets and only in first lower molars (clinically the change was small). The change in the distance WALA-FA in first lower molars on the left and on the right between T2 and T1 was statistically significant in both groups, however, it was significantly bigger in the group with self-ligating brackets. The difference in the length of therapy was not statistically significant. Conclusion: In patients with self-ligating brackets there is a greater expansion in first molars and canines. We can also observe more prominent vestibular inclination of canines and first molars. In patien