Search for candidate chromosomes that specify mesiodistal tooth crown length of the mandibular first molar using MSM, C57BL/6J and their consomic mice

Tooth size directly affects abnormalities in dental occlusion, and is decided by genetic and environmental factors. Malalignment of teeth occurs as a result of discrepancies in jaw bone and tooth size. In this study, F2 mice acquired by crossing C57BL/6J (B6) strain having large mesiodistal tooth crowns and MSM strain having small mesiodistal crowns were used to conduct quantitative trait locus (QTL) analysis and to identify chromosomes involved in determining mesiodistal tooth size. Analysis revealed that the QTL responsible for tooth size could be mapped chromosomes 3 and 17 in mice. Therefore, we measured mesiodistal crown length of the first molar of the mandible, and analyzed candidate chromosomes that decide the size of teeth in vivo using consomic mice between B6 and MSM strains. Mesiodistal crown length was largest in consomic mice of B6-Chr.3MSM, thus some genes for mesiodistal crown development may be located on chromosome 3.