Comparison of two skeletally anchored maxillary protraction protocols: a randomized clinical trial

Abstract

The aim of this study is to compare the skeletal and dentoalveolar effects produced by two maxillary protraction protocols anchored on mini-implants. Material and methods: It will be a randomized clinical trial, with 2 groups, where 40 individuals of both sexes, ages ranging from 9 to 13 years old, with class III skeletal malocclusion and mandibular canines erupted will be selected. Group 1 will consist of 20 individuals treated with class III elastics anchored in a maxillary expander with dento-skeletal anchorage and in 2 mini-implants installed in the mesial of the lower canines. Group 2 will consist of 20 individuals treated with class III elastics anchored in a maxillary expander with tooth-borne anchorage and mandibular mini-implants. Dental models and X-rays in the beginning and end of treatment will be obtained. In addition, occlusal radiographs and partial (canine to canine) models will be obtained before and immediately after expansion. In the dental models the variables intercanine and intermolar distance, arch width, perimeter and length, molars and canine inclinations, overjet and overbite will be analyzed. Cephalometric measurements of the tegumentary profile, growth pattern, apical bases relationship, and incisors relationship will be evaluated. In the occlusal radiographs and dental models, the amount of expansion promoted by the two maxillary expansion protocols will be evaluated. The paired T test will be used in the intragroup comparison, while the independent T test will be used in the intergroup comparison. A significance level of 5% will be regarded for all tests. (AU)