The upper airway volume effects produced by Hyrax, Hybrid-Hyrax, and Keles keyless expanders: a single-centre randomized controlled trial

Abstract

Summary Objective To assess upper airway volume changes after rapid maxillary expansion (RME) with three different expanders. Trial design Three-arm parallel randomized clinical trial. Methods Sixty-six patients, 10–16 years old, in permanent dentition, with maxillary transverse deficiency were recruited and assigned with block randomization (1:1:1 ratio) and allocation concealment to three groups of 22 patients each (Hyrax, Hybrid-Hyrax, and Keles keyless expander). The primary outcome (overall upper airway volume change) and secondary outcomes (volume changes in the nasal cavity, nasopharynx, oropharynx, and hypopharynx) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone beam computed tomography. Differences across groups were assessed with crude or adjusted for confounders (gender, age, growth stage, skeletal pattern, baseline airway volume, and amount of expansion) linear regression models. Results Fifty-one patients were analysed (19, 19, and 13 in the Hyrax, Hybrid-Hyrax, and Keles groups). Maxillary expansion resulted in considerable increases in total airway volume in the Hybrid-Hyrax group (+5902.1 mm3) and less in the Hyrax group (+2537.9 mm3) or the Keles group (+3001.4 mm3). However, treatment-induced changes for the primary and all secondary outcomes were of small magnitude and no significant difference was seen among the three expanderes in the total airway volume in either crude or adjusted analyses (P > 0.05 in all instances). Finally, among pre-peak patients (CVM 1–3), the Hybrid-Hyrax expander was associated with significantly greater increases in total airway volume compared to the Hyrax expander (P = 0.02). Conclusions RME resulted in relatively small increases in total upper airway volume and its separate compartments, with mostly no statistically significant differences across the Hyrax, Hybrid-Hyrax, and Keles groups. Limitations Significantly greater attrition was found in the Keles group due to appliance failure. The current trial might possibly be under-powered to detect differences between groups, if such exist. Harms Keles expanders blocked during activations and required substitution for completion of treatment. Protocol The protocol was not published before trial commencement. Registration Australian and New Zealand Clinical Trial Registry (ACTRN12617001136392).

Rapid Maxillary Expansion on the Adolescent Patient: Systematic Review and Case Report

“…The number of activations suggested was almost the same in all designs: in two studies, the screw was turned two times a day, for the first week, then the appliance was activated one time per day; the screw used was a 9 mm Hyrax for the TB group and a 9 mm Jackscrew for the MARPE TTB group [ 23 , 24 ]. In 11 studies suggested activating the screw two times a day until the finish of the expansion: the screws used in these cases were 9 mm Hyrax in the 9 TB group; a Hyrax miniscrew was used in the 1 TB group and 12 mm Hyrax jackscrew in the 1 TB group; one group used the Keles Keyless screw; in the MARPE TTB groups, two studies used 8 mm a miniexpander jackscrew and one study used a 12 mm jackscrew [ 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. Two studies suggested one activation/day with the Hyrax screw [ 36 , 37 ], and the protocol was not determined in one study [ 38 ].…”

Does rapid maxillary expansion enlarge the nasal cavity and pharyngeal airway? A three‐dimensional assessment based on validated analyses

“…To our knowledge, there are two randomized controlled clinical trials, which have evaluated airway changes following RME treatment 11,12 . However, none of these studies included inactive control groups.…”

“…10 To our knowledge, there are two randomized controlled clinical trials, which have evaluated airway changes following RME treatment. 11,12 However, none of these studies included inactive control groups. Thus, the real influence of RME on nasal airway dimensions and functions, considering the influence of growth, has not been fully elucidated.…”

Avaliação das alterações esqueléticas e dentais após a expansão rápida da maxila com expansores dentossuportados e dento-ósseo-suportados: estudo clínico randomizado

“…Isso sugere um dos benefícios do Hyrax híbrido com relação à melhoria da respiração, como já foi mencionado por Motro et al (2016), que encontraram efeitos positivos de aumento de volume aéreo em indivíduos tratados com Hyrax híbrido com idade mais avançada (17 anos), que foram semelhantes aos resultados encontrados em indivíduos tratados com aparelhos dentossuportados com idade média de 14 anos. Cheung et al (2020), apresentaram também resultados positivos do Hyrax híbrido com relação ao aumento das vias aéreas superiores. Observou-se que pacientes na fase de pico de crescimento puberal apresentaram resultados melhores no aumento total das vias aéreas, quando comparado ao Hyrax e ao disjuntor Keles (dentossuportado).…”

“…Canan et al (2017), estudaram os efeitos da ERM por meio da sobreposição de modelos digitais, com os dispositivos Hyrax, Hyrax híbrido e MARPE (micro-implant asisted rapid palatal expansion), e mostraram que não houve diferenças com relação à inclinação dos dentes posteriores entre os três grupos avaliados. Cheung et al (2020), encontraram um maior aumento do volume aéreo em pacientes tratados com o Hyrax híbrido, quando comparados com pacientes tratados com dispositivos dentossuportados. Garib et al (2021), observaram maiores efeitos esqueléticos na cavidade nasal e nas dimensões da maxila, em pacientes tratados com o Hyrax híbrido.…”