Abstract
The purpose of this study was to investigate the relationship between the biting force and the activities of masticatory muscles in children. The present report deals with the measuring points and the reproducibility as to present parameters.
Three children with deciduous dentition and three adults with permanent dentition, who had any symptoms in the gnatho-facial function, were examined. The measurement was performed three times at intervals of two or three days. EMGs were taken from the right temporalis and masseter muscles by using bipolar surface electrodes, and biting forces were measured at the right second deciduous molars in children and the right first molars in adults with aid of bite transducers placed inter-maxillary.
Six parameters were chosen for the measuring points, such as (1) maximum bite force (MBF), (2) the time of MBF (MBFT), (3) the speed of the maximum bite (MBS), (4) the time of MBS (MBST), (5) the integrated EMG of the temporalis muscle (IET), and (6) the integrated EMG of the masseter muscle (IEM). Results obtained in the present study are summarized as follows:
1 It was noticed that all parameters revealed reproducibility in both children and adults. While three parameters such as MBFT, MBS and MBST, showed some varieties among subjects and the various day of the experiment.
2 The values of four parameters such as IET, IEM, MBF and MBS were significantly lower in children compared with those of adults (p<0.005).
