REMOVED: Comparison between two different expansion protocols in early mixed dentition: Clear Aligners vs Rapid Maxillary Expansion

Abstract

Aim to compare the effects of two different expansion protocols in terms of bi-dimensional linear, angular measurements, and three-dimensional analysis of palatal area on digital casts in patients with mixed dentition. Methods digital casts of 32 children treated with the RME (RG: 17 subjects), or with clear aligners (FG: 15 subjects) were collected. Linear and angular values were measured in both groups on the upper arch for each pre (T1) and post-treatment (T2) models, as well as palatal area. Unpaired t-test was used to test significant differences between groups (p<0.05). Results the comparison of T2-T1 changes for linear measurements between groups showed significant differences in the inter-canine width (+1.5mm in FG), in the first inter-deciduous molar width (+1.5mm in FG), in the first inter-molar distal width (-1.2mm in FG), in the inter-canine transpalatal width (+1.5mm in FG) and in the first inter-deciduous molar transpalatal width (+1.4mm in FG). The analysis of angular measurements showed a significant increase of the crown angulation for all the teeth in FG except for the second deciduous molars and for the first molars. First molars showed a reduction of this parameter. FG patients showed a greater increase of the palatal area. Conclusions the comparison between FG and RG groups pointed out that clear aligners system seems to be more efficient than RME in terms of expansion obtainable at the anterior segment of the arch with a better control of upper first molar crown angulation and a greater increase of the palatal area.