Root and root canal diversity in human permanent maxillary first premolars and first molars in inhabitants from the ancient Middle Euphrates Valley (Syria).

The morphological and anatomical structure of the roots and root canals of human dentition is very diverse. This means that tooth morphology can effectively differentiate populations and be used in both contemporary and historical research populations. The aim of the study was to investigate whether historical populations from the Middle East showed variation in the number of tooth roots and the morphology of canal systems. The tooth material used for the research was obtained from three sites: Terqa, Tell Masaikh, and Jabel Mashtale (Syria) during archaeological expeditions. The odontological material has been divided into three historical periods: Bronze (2,650-1700 BC), late Roman (200-500 AD) with Islamic (600-1,200 AD), and Modern (1850-1950 AD). The teeth of 31 individuals of both sexes were collected for analysis, with a total of 73 teeth examined. The subjects underwent cone-beam computed tomography (CBCT) analysis. The greatest variation in the number of roots and root canal configurations occurred in the Late Roman and Islamic periods. In addition to the typical number of tooth roots and their characteristic root canal configurations, the presence of less typical morphological forms was noticed in each type of tooth analyzed during this period. This may indicate the influx of new genes and their mixing with local ones, which was reflected in the morphological variability. The presented studies, although they must be continued, already indicate that the analysis of root and canal variability broadens the spectrum of odontological studies conducted on historical populations.