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Previous issue date: 2012-03-14 / Introduction: The aim of this study was to evaluate and compare the effects on the sagittal and vertical position of the jaw resulting from rapid maxillary expansion (RME), with Haas- type and Hyrax- type expanders by using cone beam computed tomography. Methodology: The sample consisted of 33 subjects with transverse maxillary deficiency (mean age 10.7 years) randomly divided into 2 groups: Haas (n = 18) and Hyrax (n = 15). All patients underwent the same activation protocol, a total of 8 mm expansion reached to the end of the ERM. The evaluation was performed on CBCT scans of the face using the Efilm software in the times: T1 (initial), T2 (after the active phase of the ERM) and T3 (after 6 months stabilized the screw expander). Dentoskeletal measures undertaken in the maxilla and mandible were analyzed and compared by analysis of variance with repeated measures with mixed model, considering the significance level of 5%. Results: Immediately after RME (T2), mandibular displacement back (SNB; p= 0,024) and down (SN.PM; p= 0,007), an increasing in lower anterior face height (ENA-ME; p= 0,001) and a tendency to open bite occurred in both groups. These changes tended to return to values similar to the initial retention period (T3). The verticalization of the lower molars was verified, in T3, and extrusion in relation to the mandibular plane in T2. Conclusion: The ERM caused mandible displacement backward and downward, increasing in lower anterior face height and a tendency to bite opening immediately after RME. However, these effects were temporary. The lower molars showed a tendency to verticalize after 6-months retention period. The Haas-type and Hyrax-type expanders showed similar results. / Introdu??o: O objetivo deste estudo foi avaliar e comparar os efeitos na posi??o sagital e vertical da mand?bula, decorrentes da expans?o r?pida da maxila (ERM), com os aparelhos tipo Haas e Hyrax, atrav?s de tomografia computadorizada cone beam. Metodologia: a amostra foi composta de 33 pacientes com defici?ncia transversal da maxila (m?dia de idade de 10.7 anos) divididos aleatoriamente em 2 grupos: Haas (n=18) e Hyrax (n=15). Todos os pacientes foram submetidos ao mesmo protocolo de ativa??o, totalizando 8 mm de abertura do parafuso expansor ao final da ERM. A avalia??o foi realizada em tomografia computadorizadas cone beam com aux?lio do software E-Film nos tempos: T1 (inicial), T2 (ap?s a fase ativa da ERM) e T3 (ap?s 6 meses estabilizado o parafuso expansor). As medidas maxilares e mandibulares, esquel?ticas e dent?rias, foram analisadas e comparadas atrav?s da an?lise de vari?ncia de modelo misto com medidas repetidas, considerando o n?vel de signific?ncia de 5%. Resultados: imediatamente ap?s a ERM (T2), ocorreu, nos dois grupos, deslocamento mandibular para tr?s (SNB; p= 0,024) e para baixo (SN.PM; p= 0,007), aumento das dimens?es do 1/3 inferior da face (ENA-ME; p= 0,001), tend?ncia de abertura da mordida. Essas altera??es tenderam a retornar a valores pr?ximos aos inicias no per?odo de conten??o (T3). Foi verificada a verticaliza??o dos molares inferiores, em T3, e a extrus?o em rela??o ao plano mandibular em T2. Conclus?o: a ERM provocou deslocamento da mand?bula para tr?s e para baixo, aumento das dimens?es do 1/3 inferior da face e tend?ncia de abertura da mordida imediatamente ap?s a ERM. No entanto, esses efeitos foram tempor?rios. Os molares inferiores apresentaram a tend?ncia de verticaliza??o ap?s 6 meses de conten??o. Os aparelhos tipo Haas e tipo Hyrax apresentaram comportamento semelhante.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/1161 |
| Date | 14 March 2012 |
| Creators | Reale, Chalana Sangalli |
| Contributors | Menezes, Luciane Macedo de |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Odontologia, PUCRS, BR, Faculdade de Odontologia |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | -8096554818733665164, 500, 600, 4673435736271820140 |
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