Abstract
In this article, the author examined the difference in the susceptibility to tooth attrition between C 57 BL/6 and C 3 H mice. These mice,21 days old, were divided into 4 groups as follows, the solid standard chow, the powdered standard chow, the solid high-cholesterol diet and the powdered highcholesterol diet groups. Mandibular bones were obtained at 150 days or 240 days after commencement of the experiment. Attrition in the molars was observed using Micro-CT and compared among the four groups. The degrees of attrition were evaluated according to areas of dentin exposure on the occlusal surface and the volume of the crown. In all of the groups, C 3 H mice showed a higher level of attrition compared with C 57 BL/6 mice. C 3 H mice fed with a powdered high-cholesterol diet for 240 days showed significant attrition among all of the C 3 H groups. The author therefore concluded that C 57 BL/6 mice were less susceptible to attrition than C 3 H mice. The purpose of this study was to examine the inheritance factor affecting attrition. Two mice strains F 1 (8) and F 2 (16) were fed with high-choresterol diet for 240 days. The levels of susceptibility to attrition between the two strains were then evaluated using methods mention above.
The results showed that all F 1 (8) mice were in the low group, while F 2 mice were di vided into high and low groups (7 mice were in the high group and 9 mice were in the low group).
According to the results, C 3 H mice were more susceptible to attrition than C 57 BL /6 mice. The author seemed to obtain model mice strains with high and low susceptibility to attrition, respectively. Since F 2 mice were divided into two groups, the author suggested that the trait involving attrition was inherited separately in F 2 mice.
