Abstract
The present study was carried out to determine what kind of influence would be exerted on the masticatory muscle activities of infants by the difference of hardnesses of different brands of biscuits, which are one of the commonest foods given to them.
The study subjects were 6 infants presumably in normal occlusion in Hellman's Dental Age IIA. As for chewing material, biscuits containing the same gredients were selectively used. There were three kinds, soft-45 g/mm (mean), medium-82 g/mm (mean) and hard-132 g/mm (mean) biscuits.
The electromyographs were taken of bilateral right and left anterior temporal muscle (TA) and masseter muscle (M) from the beginning of free chewing of these biscuits to the completion of swallowing.
The resultant mesurement data were comparatively analyzed in terms of the amount of muscle activities (integrated values), masticatory rhythm, number of masticatory strokes and length of masticatory time for the purpose of bringing out differences due to these three kinds of biscuits.
