[Electromyographic study on motor skill in chewing movement. A new concept on relating electromyographic analysis to chewing movements].

This article was aimed to propose a new concept on evaluating electromyographic activities of masticatory muscles during chewing movements viewed from the standpoint of motor skill. Correlation coefficients between the ratio of lateral distance to ten vertical level set at 0.5 mm to 5.

[Relationships between tooth loss and electromyographic activities of masticatory muscles].

For purpose of evaluating the characteristic of electromyographic activities of masticatory muscles with front or molar tooth loss, electromyographic activities of masticatory muscles and mandibular movements during tooth tapping and gum chewing were investigated in each group of tooth loss, and were compared with those of control group. The results were as follows. 1.

[Psychosomatic aspects of the patients with stomatognathic dysfunction. 2].

Various kinds of mind stress are prevalent in our society today. Especially, in the current society, number of patients who suffered from mind stress have been increased. And to our interest, many of them tended to show dysfunction in stomatognathic system.

[Electromyographic study on the effects of head position to head and neck muscles].

The purpose of this study is to reveal the relationship between the head position, and the neck and head muscles. At 4 head positions, the activities of masseter, anterior temporal, anterior digastric, sternocleidomastoid and trapezius muscle of ten normal subjects standing straight were investigated electromyographically with surface electrodes during voluntary maximal clenching in centric occlusion. Head positions were right tilting, left tilting, up-right and natural head position.

Clinical classification of maximal opening and closing movements.

Opening and closing mandibular border movements of 250 subjects, 130 with clinical signs of TMJ pathosis and 120 normal subjects, were evaluated by measuring incisal interocclusal distance and recording mandibular movement on a tracking device. Both maximal opening and closing pathways were divided into initial and secondary phases, and were further classified into seven patterns on the basis of anomalous mandibular movements. Subjects with TMJ sounds tended to show mandibular deviations in the second phase, while those with tenderness to muscle palpation tended to show deviations in both phases.

[Electromyographic study on lateral jaw movements].

This study aims to analyse how jaw-closing muscle activities are modulated during lateral jaw movement. Jaw movements were recorded by Sirognathograph (Siemens Co.) and electromyograms were simultaneously recorded from bilateral masseter, anterior temporal and posterior temporal muscles in 20 young adults without any stomatognathic dysfunction.