Abstract:
PROPOSITION: This study aimed at comparing the changes in upper and lower dental arches dimensions as well as the changes in upper and lower incisors positions, comprehending cases treated with no dental extractions performed with conventional braces and Morelli SLI self-ligating brackets. MATERIAL AND METHODS: the sample was composed of unitial (T1) and final (T2) dental casts from 61 patients with Class 1 malocclusion, treated with no dental extraction as well as presenting mild to moderate crowding, divided into two groups. Group 1: 31 patients treated with Morelli SLI self-ligating braces, initial average age of 21,87 years old and average length of treatment 2,39 years. Group 2: 3o patients treated with conventional braces, initially average age 14,98 years old and average length of treatment 1,8 years. The distances of upper and lower dental arches were measured from intercanines, interpremolars (first and second interpremolars), intermolars and dental arch length. In addition to this, the measurements of 1.NA, 1-NA, 1.NB, 1-NB and IMPA were made. The comparison between the groups was made with t independent test. RESULTS: Morelli SLI group showed a significantly bigger increase in the upper transversal distances than the conventional group. The change of the upper arch length did not show any difference between the groups. Concerning the lower arch, Morelli SLI group showed a significantly bigger increase in the intercanines and first interpremolars distances than the conventional group. The change in the upper incisors position was bigger in the conventional group than in Morelli SLI group. CONCLUSIONS: the treatment performed with Morelli SLI braces resulted in a significantly bigger increase in transversal dimensions of the upper arch when compared with the conventional braces. In the lower arch, the intercanines and interpremolars distances also showed a more substantial increase in Morelli SLI braces than the conventional. Regarding the biggest change in the upper incisors position from the conventional group, it was possible to observe that Morelli SLI self-ligating brackets resulted in a bigger transversal expansion than the conventional group.
