Estudo comparativo entre os HYRAX e HAAS para expansão da maxila: uma revisão de literatura

Abstract

Maxillary atresia consists of narrowing the upper arch, it is a skeletal malocclusion in the transverse direction that does not self-correct. The treatment consists of rapid maxillary expansion, a mechanical orthopedic procedure that results in the opening of the medial palatal suture, which can be used in the primary dentition or in the beginning of the mixed dentition. Its etiology is multifactorial and may be genetic, physiological or due to parafunctional habits. The aim of this study was to evaluate the results of rapid maxillary expansion, comparing the Hyrax and Haas devices. A narrative-type literature review was carried out by searching for scientific articles in the SciELO, MEDLINE and LILACS databases, published between 2009 and 2020, using the following descriptors: maxilla, palatal expansion technique and orthodontics. According to the literature, the most widely used expander devices for maxillary disjunction are those of the Hyrax and Haas type, indicated for young patients with incomplete maxillary bone maturation, for women the maximum age is 14 years and 16 years for men. In adults, this treatment must be associated with surgery. It was concluded that despite having differences between them, the Haas and Hyrax expanders promote similar results. The main difference consists of the presence of the acrylic coating in Haas, whereas Hyrax's does not have and facilitates hygiene and also the Haas appliance provides greater orthopedic and minor orthodontic effects, while Hyrax's presents the opposite. Regardless of the device used, containment must be performed so that complete bone neoformation occurs and no recurrences occur.