Abstract
The purpose of this study was to investigate the causative factors of attrition. The authors analyzed two strains of mice which have different susceptibility to attrition. These mice,21 days old, were divided into 2 groups as follow, the solid standard chow group and the powdered high-cholesterol diet group. Mandibular bones were obtained at 240 days after the start of the experiment. The authors compared the mandibular angle, dentin exposure in the occlusal surface and the volume of saliva between the two strains.
The mandibu lar angles of the solid standard chow group were significantly smaller in the C3H mice than those in the C57 BL/6 mice. The results suggested that the C3H mice might have a stronger occlusal force.
The dentin exposure in occlusal the surface of the powdered high-cholesterol diet group was observed using SEM. The exposure in the C57 BL/6 mice was smooth while on the other hand, that in the C3H mice was rough. It is also thought that there are differences in the tooth substance and the jaw movement between the two strains.
The authors gave medicated p ilocarpine to the mice in the solid standard chow group at 90 days, and measured the volume of the saliva extracted for three minutes. The results showed that the volume was obviously greater in the C3H mice than that in the C57 BL/6 mice, and the possibility of a connection between saliva and tooth attrition was suggested.
In this study, we suggest that tooth attrition is connected with the mandibular angle, tooth substance and jaw movement.
