Abstract
Electromyographic studies were performed to find out the relationship between the development of the orthognatic systems in children and the change of the electromyogram patterns of their masticatory muscles. The correlations between the sizes of their dental arch and the electromyographic parameters were also investigated. The main findings were as follows.
1. The integrated values of the electromyograms of gum-chewing and maximum biting showed that the occlusal development in children corresponded to the change of the occlusal function from the TA-type mastication to the M-type mastication.
2. Powerspectral analyses of the electromyograms of gum-chewing showed that the powerspectrums shift of lower frequencies occurs when they developed.
3. The integrated values of the electromyograms of maximum biting showed that the M-type was more easily fatigued compared to the TA-type.
4. Though some factors such as the sizes of the dental arches had some correlation with the integrated values of the electromyogram, we were not able to find out evidence enough to account for their relationship.
