DIFERENÇA ENTRE DISPOSITIVOS DE EXPANSÃO DA MAXILA: Haas x Hyrax

Maxillary atresia is a bone deformity that causes several problems, even in the primary dentition.Speaking, breathing, swallowing and especially occlusion make this problem a concern in the lives of patients and extremely urgent in its treatment so that, in the future, more complicated treatments are not necessary. Maxillary disjunction is an interceptive technique for treating cases of malocclusion resulting from maxillary atresia, which consists of a transverse increase in order to restore a balanced relationship between the periodic arches. Disjunction devices are those that produce overloaded forces on the palate and that act to open the median palatal suture in a short period of time. The Haas appliance is a fixed switch featuring a metallic structure positioned on the first permanent molars, with acrylic resin support on the palate, joined by an expansion screw and its main characteristic is the fact that it has tooth-mucus-supported anchorage. The Hyrax device is also considered a fixed and tooth-supported anchorage switch, but it has the advantage,
in relation to the device described by Haas, which is the ease of cleaning due to the absence of acrylic coverage on the palate, which caused irritation in the soft tissue due to to food impaction under this. A literary search was carried out through the databases PUBMED, SCIELO, LILASC, MEDLINE, SCI-HUB and several other libraries that had literature on the subject of studies from the last 20 years, and in special studies between the years 2018 and 2023. Articles in English and Portuguese that specifically addressed the aforementioned events were included in the research. The results of using both devices are similar among some of the authors trained in relation to maxillary disjunction and no superiority was found between them. What must be done is the correct indication, diagnosis and proper monitoring. Conclude that the differences regarding the disjunction of both devices are few, but that the orthodontist has the freedom to choose which device to use, his clinical experience and the device that best suits each case.