Comparison of the Tooth Shape and Size in tabby and Non-tabby Mice

Basic anatomical and embryological investigations of the dental disorder in tabby mice were performed some 20-30 years ago. In order to bridge the gap in research activity in this field and as a prerequisite for future developmental studies, the dental characteristics of the tabby mice were updated in a stock presently available. Qualitative and quantitative parameters of the functional teeth were determined in 50 males and females of different phenotypes segregated from the stock of tabby mice. A parallel investigation was made in a common laboratory mouse (ICR stock). In ICR mice. the body weight was two times higher and this was reflected in the cheek teeth which were significantly larger (but similar in shape) when compared to the wild type non-tabby controls. Among tabby homozygous and hemizygous mice, at least one incisor was absent in 50% of females. and in 70% of males -where predominance of the right side was apparent. In these groups the mean length and width of the cheek teeth were significantly reduced compared to the corresponding wild type controls, despite similar body weight. Changes in crown pattern. including also reduction or absence of cusps. resulted in characteristic morphology of the cheek teeth. In contrast to the earlier literature, duplication of an incisor or an explicit supernumerary tooth in the cheek region were not found in the present tabby collection and the heterozygous specimens were less affected.