こう合面形態が頬舌側のモーメントに及ぼす影響

Abstract

n order to investigate the effect of the occlusal form on the lateral force transmitted to a tooth during mastication, the buccolingual forces were measured as the moment occurring around the center of tooth rotation.The four following types of occlusal form were adopted: the basic form (type B), the form in which the outer half of the functional cusp was partially eliminated (type OF), and the forms in which the buccal or lingual cusp was totally eliminated from the type B (type FC or type NC).These types had no occlusal contact at the intercuspal position and lateral excursion.Buccal and lingual moments were measured by load cells which were contained in a bridge at the missing lower first molar.The results obtained were as follows:1.The buccal moment was observed more frequently than the lingual moment.2.The interocclusal space, at which the moments occurred, decreased according to the progress of mastication.And the moments were observed near the intercuspal position.3.Differences were observed in the frequency and the intenstiy of the moments among subjective foods.4.The lingual moment was larger and the buccal moment was smaller in the type OF than in the type B.5.The buccal moment was smaller in the type FC than in the type B.However, little difference was observed between the lingual moments of these two types.