Dental phenotypic variability in an archaeological human population of the 16th–19th centuries from Iaşi city (Romania)

• Phenotypic diversity in the human population from Iaşi city, in the 16th–19th centuries, supports gene flow and mobility. • The dental material subjected to geometric morphometric techniques is represented by the second mandibular molar. • The plasticity of mesial surface of the molar was found to define the dental phenotypic patterns in the studied population. This study aims to assess the variability of dental morphology within a human population from the 16th to the 19th centuries, addressing a topic of interest for anthropological and historical research. Through this study we aim to provide additional evidence to support the hypothesis that the Iaşi city was a cosmopolitan center since the early stages of the modern period. The assessment of phenotypic variability was achieved with the method of Geometric Morphometrics. Bidimensional data were collected using a set of landmarks located on the occlusal surface and outline of the permanent lower second molars from three archaeological sites at Iaşi city. The results of the study, as described through centroid size and shape analysis, support the identification of distinct dental phenotypic patterns characteristic of human samples from the three necropolises. Also, the cusp patterns and their shape constitute more reliable elements than centroid size for sexual dimorphism in the studied material. Allometry has a statistically significant influence in the shape variation of molars between females and males but insignificant in the variation of dental shape in the three necropolises. The distinguishing elements between the dental phenotypic patterns within the urban human population of the 16th-19th centuries are the mesial area of ​​the molar through the variability of the two cusps (protoconid and metaconid). The talonid of the permanent lower second molars is a feature shared in the identified phenotypic models, this area being an element of shape stability. This work on dental morphology provides useful information for comparative studies in past and present human populations.