Eficácia de contenções fixas e removíveis na prevenção da recidiva do apinhamento anteroinferior

Abstract

Introduction: 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. Objective: The aim of this study was to conduct a pilot study in order to analyze and compare the effectiveness of fixed and removable orthodontics retainers regarding prevention of the lower anterior crowding relapse after the active phase of orthodontic treatment in patients of a Specialization Course in Orthodontics and Facial Orthopedics in Belo Horizonte, Minas Gerais. Methods: A randomly sample of 23 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. Results: Although the greatest variability in Irregularity Index in Group 2 (Group 1 median: 0.47; interquartile range: [0.02; 0.89]; Group: 2 median: 0.82; interquartile range: [0.31; 3.22]), there were no statistically significant differences in the degree of crowding relapse in T2 between the two groups (p = 0,084). Conclusions: The two types of orthodontics retainers analyzed have statistically similar efficacy in maintaining the lower anterior alignment, after the active orthodontic treatment.