OBSERVATIONS ON SEXUAL SIMILARITY AND BILATERAL DISTRIBUTION IN DENTAL CARIES INCIDENCE IN ALBINO RATS AND COTTON RATS

¹ Harvard School of Dental Medicine, Boston, Mass.

The caries-susceptibility of males and females has been compared in 1,401 albino rats and 1,314 cotton rats. In addition, the degree of bilateral symmetry in the distribution of various lesions among the same experimental subjects has been determined.

No difference in caries-susceptibility was observed between males and females of these two species. This similarity between the sexes was noted among both caries-susceptible and caries-resistant groups.

A high degree of bilateral symmetry was observed in the distribution of carious lesions in these species. However, this degree was correlated with the caries-susceptibility of the individual animals, teeth and grooves. Bilateral symmetry was greater in caries-susceptible groups of rodents than in the caries-resistant groups. Bilateral symmetry was also greater in the more susceptible pairs of grooves and teeth than in the more resistant pairs.