Koichi Nishio

Clinical study on the analysis of chewing movements in relation to occlusion.

AbstractThe purpose of this study was to examine how the occlusal factor influences the chewing movement. The subjects were divided into two groups; one consisted of 10 subjects whose chewing patterns look like grinding movements, which we named “grinding type,” and another consisted of 15 subjects whose chewing patterns look like chopping movements, which we named “chopping type.” The distance of separation between the lower functional cusp tips and the upper teeth in centric occlusion and at lateral mandibular position was measured and analyzed in the two groups. In centric occlusion, the distancewas less in the chopping type than in the grinding type. On the contrary, at lateral mandibular position, the distance was less in the grinding type.This study suggests that the chewing pattern has some relationship to occlusion, especially to the distance between the upper and the lower posterior teeth in the lateral mandibular position.

A clinical Study on Chewing Movements in Open Bite. Part I. Effect of the Range of Open Bite on Chewing Movements.

It is important to grasp the functional characteristics of open bite, because those who are open bite have problems on anterior guidance and many of them show TMJ dysfunction. However the effect of open bite on stomatognathic function has not been clarified.The purposes of this study are to investigate 1) the characteristics of chewing patterns in subjects with open bite and 2) the relationship between each chewing pattern and the location of open bite.14 normal subjects were selected as a control group, and 14 open bite subjects were selected and clinically classified by the location of open bite, as follows1) anterior open bite2) anterior and posterior open biteChewing movements of each subject were recorded and qualitatively analysed by Sirognathograph Analysing System II.As a result, characteristic chewing patterns were observed in subjects with open bite, and some of which have relationships with the location of open bite.