Comparative dental morphology of hamsters and Guinea pigs through µ-CT scanning and stereology

This study aims to elucidate the morphometric and morphological details of teeth in the Syrian hamster (Mesocricetus auratus, Waterhouse, 1839) and guinea pig (Cavia porcellus, Linnaeus, 1758) using µ-CT and stereology (n = 5). Notably, the hamsters exhibited distinctive roots in their cheek teeth, in contrast to the guinea pigs, where the tooth body extended as a dental root into the alveolar socket, making anatomical diagnosis challenging. The first and second cheek teeth of the hamster had four roots, but the last one had three roots. The hamster incisor teeth had a more voluminous pulp cavity compared to those of guinea pigs. While the ratio differences of arch parameters and enamel thickness were not statistically significant (P ≥ 0.05). The enamel layer in guinea pig incisor teeth were significantly thicker than that in the hamster teeth (P ≤ 0.05). Regarding the dentine-tooth width, the difference between the upper incisor teeth of the hamster and guinea pig was significant (P ≤ 0.05). The ratio of pulp-tooth volume in all incisor teeth of the hamster was significantly higher than that in the guinea pig's teeth (P ≤ 0.05) indicating hamsters might have better regenerative dental health despite dietary variances. These insights contribute to deeper understanding of the evolutionary adaptations in rodent dentition and suggest improved information and methodologies for translational dental studies and selecting more appropriate animal models in dental research.