Frontal chewing patterns of the incisor point and their dependence on resistance of food and type of occlusion.

This study has shown that mastication in normal dentate subjects is associated with a great variety of movement modes. The dependence of chewing patterns on the resistance of food proves that the chewing system is capable of marked variations. A complete assessment of chewing behavior therefore demands the use of both tough and soft foods. Physiologic chewing of tough food is dominated by angulated grinding-type movements, whereas soft consistencies are chewed with drop-shaped or lenticular patterns. In a random sample of patients with good chewing function, approximately 95% of Angle class I and II occlusions were found, which statistically differed neither in chewing pattern distribution nor in movement parameters. As shown in this study, certain occlusal or functional properties cannot be characterized by a single type of chewing pattern but instead by a specific distribution of patterns. As a basis for the evaluation of such investigations, a method for the classification and ordered documentation of observed movement modes is necessary. The scheme used here includes all types of chewing movements that have been presently observed. It permits the recognition of patterns and the quantitative description of their frequencies and variations.