Ⅲ급 부정교합 아동의 교정 치료시 저작근의 근전도 POWER SPECTRUM 변화에 관한 연구|RISS 상세보기

다국어 초록 (Multilingual Abstract)

The purpose of this study is to evaluate the changes in the electromyographic power spectrum of the masticatory muscles before and after treatment of the class Ⅲ malocclusion children.
Twenty one children with class Ⅲ malocclusion, seventeen children with mormal occlasion, and thirteen children who received orthodontic treatment were included in this study.
Class Ⅲ malocclusion children were treated with Frankel appliances.
The myoeletric signals from the masseter and anterior temporal muscles were recorded for thirty seconds in 80% level of maximum voluntary contraction using computer-aided EMG system.
The power spectral analyses were done with computer and the following results were obtained :
1. In all subjects the median frequency of the electromyographic power spectrum of both muscles showed shift to lower frequency range as isometric contraction was sustained(P<0.001).
2. The slope of median frequency in normal occlusion children was a little higher than that in class Ⅲ malocclusion children, but did not show any significant difference statistically.
3. After treatment the slope of median frequency increased slightly, but did not show any significant difference statistically.
4. After treatment the median frequency of the 1st block dropped significantly in both muscles, and the temporal muscle showed greater drop than the masseter muscle(masseter muscle:P<0.05, temporal muscle:P<0.001).
5. After treatment the median frequency of the 30th block dropped significantly in both muscles, and the temporal muscle showed greater drop than the masseter muscle(masseter muscle:P<0.05, temporal muscle:P<0.001)
6. After treatment the mean value of the median frequencies for thirty seconds dropped significantly in both muscles, and the temporal muscle showed greater drop than the masseter muscle(masseter muscle:P<0.01, temporal muscle :P<0.001).

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