Análise comparativa da eficácia dos aparelhos de contenção fixos e removíveis na prevenção da recidiva do apinhamento anteroinferior: um estudo-piloto

Abstract

The relapse of the lower anterior crowding is a recurrent problem and one of the factors that lead patients to opt for orthodontic retreatment. However, there is no agreement in the literature about the effectiveness of various types of orthodontics retainers used. The aim of this study is to conduct a pilot study in order to analyze and compare the effectiveness of fixed and removable orthodontics retainers regarding prevention of relapse of the lower anterior crowding after the active phase of orthodontic treatment in patients of the Specialization Course in Orthodontics and Facial Orthopedics at School of Dentistry, Universidade Federal de Minas Gerais. A randomly sample of 28 patients in retention control phase was recruited and divided into two groups: Group 1: fixed retainer; Group 2: removable retainer. The Irregularity Index of Little was used to measure the lower anterior crowding, by analysis of plaster casts made before treatment (T0), after treatment (T1) and at least one year after treatment (T2). The statistical Mann-Whitney and Signals tests were performed to evaluate the variation of crowding along the three times. Although the greatest variability in Irregularity Index in Group 2 (Group: 1median: 0,47; interquartile range: [0,02; 0,89]; Group: 2median: 0,82; interquartile range: [0,31; 3,22]), there were no statistically significant differences in the degree of relapse of crowding in T2 between the two groups (p = 0,084). The two types of orthodontics retainers analyzed have statistically similar efficacy in maintaining the lower anterior alignment, after the active orthodontic treatment.