Oral myofunctional and electromyographic evaluation of the orbicularis oris and mentalis muscles in patients with class II/1 malocclusion submitted to first premolar extraction

OBJECTIVE: The aim of this study was to assess the presence of oral myofunctional alterations before and after first premolar extraction in Class II/1 malocclusion patients that could endanger the long-term dental arch stability. MATERIAL AND METHODS: The study was performed by means of morphologica...

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Detalles Bibliográficos
Autores: Souza, Denize Ramirez de [UNIFESP], Semeghini, Tatiana Adamov, Kroll, Lucio Benedito, Berzin, Fausto
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2008
País:Brasil
Institución:Universidade Federal de São Paulo (UNIFESP)
Repositorio:Repositório Institucional da UNIFESP
Idioma:inglés
OAI Identifier:oai:repositorio.unifesp.br:11600/4449
Acceso en línea:http://dx.doi.org/10.1590/S1678-77572008000300012
http://repositorio.unifesp.br/handle/11600/4449
Access Level:acceso abierto
Palabra clave:Orbicularis oris muscles
Mentalis muscle
Electromyography
Oral myofunctional evaluation
Tooth extractions
Descripción
Sumario:OBJECTIVE: The aim of this study was to assess the presence of oral myofunctional alterations before and after first premolar extraction in Class II/1 malocclusion patients that could endanger the long-term dental arch stability. MATERIAL AND METHODS: The study was performed by means of morphological, functional and electromyographic analyses in 17 Class II/1 malocclusion patients (group T) and 17 Class I malocclusion patients (group C -control), both groups with 12-30-year age range (mean age: 20.93 ± 4.94 years). RESULTS: Data analyzed statistically by Student's t-test showed a significant decrease (p<0.05) in the maxillary and mandibular dental arch perimeters after orthodontic treatment, but lip posture at rest did not present statistically significant differences after treatment (p>0.05). The Kruskal-Wallis test analyzed data from lip posture (orbicularis oris muscle) at rest and during swallowing, as well as the mentalis muscle behavior during the above-mentioned function, not showing statistically significant differences (p>0.05) after treatment (groups T1 and T2). However, group T differed significantly from group C (p<0.05). Lip posture during swallowing showed statistically significant differences (p<0.05) for subjects submitted to orthodontic therapy when compared to data acquired before the treatment. The electromyographic analysis confirmed these data. CONCLUSIONS: Found myofunctional alterations observed after the orthodontic treatment in Class II/1 malocclusion seemed to jeopardize the long-term orthodontic stability, making recurrence possible.