Electromyographic analysis of the masseter, temporal and orbicularis oris muscles in young people with class II, division 1 malocclusion after treatment with extraoral appliance of occipital traction / Analise eletromiografica dos musculos masseter, temporal e orbicular da boca em jovens com maloclusão classe II, 1ª divisão dentaria, apos o uso de aparelho extrabucal de tração occipital

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

The surface electromyography is an excellent way to evaluate the muscle function. However, it presents limitations, because the great variability in the amplitude of the electromyographic signal obtained. To reduce this variability, has been proposed the normalization of the electromyographic signal. The process consist of dividing the raw electromyographic recorder signal by a reference value expressed as a percentage, derived from measure of the electromyographic signal itself. The purpose of this study was to evaluate electromyographically the action potential of the superficial masseter muscle, the anterior temporal muscle, the orbicularis oris muscle, upper and lower segment, bilaterally, in 25 young females, aged ranging from 8 to 10 years old, with Class II division 1 malocclusion after the treatment with extraoral appliances and to compare them with 25 young females with normal occlusion, with similar aged. And to evaluate if the experiment final results can be influenced by the normalization of electromyographic data. The electromyographic signals of the masseter and temporal muscles were adquired by active single differential surface electrodes, and of the orbicularis oris muscle by passive surface electrodes of the Ag/AgCl. Muscle activity was recorded in resting position, in isometric contraction and in isotonic contraction, before and after orthodontic treatment in the malocclusion group and similar periods in the normal occlusion group. Through of specific software was determined the Root Mean Square (RMS) values of each movement. The initial data collected were submitted to the normalization procedure and were compared with the initial raw data, through of statistical analyses of variance. The results showed that the normalization procedure was able to affect the electromyographic data, suppressing the difference between the groups. This support the idea that the raw data were able to produce better conclusions than normalized data. Thus, the orthodontic treatment of the malocclusion group was evaluated using the raw data, through of statistical analyses of variance and Tukey test (α=0,05). The results showed that there was decrease of the electromyographic activity in all the muscles, in both groups difference between the groups, but that difference was not statistically significant for the right temporal muscle and the orbicularis oris muscle upper segment The muscle activity was higher in the malocclusion group than normal occlusion group in the initial phase, but that difference was not statistically significant for the masseter muscle. In the final phase there was not significant difference between the groups. It was concluding that the treatment with extraoral appliances was able to improve the muscular pattern of the young females with Class II division 1 malocclusion.

ASSUNTO(S)

orthodontics eletromiografia orthodontic appliances orthodontics aparelhos ortodônticos ortodontia interceptora electromyography interceptive ortodontia

ACESSO AO ARTIGO

Documentos Relacionados