Dental wear in a marine economy: A case study from Philistine Ashkelon

In the Iron Age IIA Philistine cemetery at Ashkelon (modern Israel), roughly 11% of individuals exhibit severe and highly variable dental wear, which we explore here at two timescales: wear that accumulates over days and weeks (microwear) and wear that accumulates over months and years (macrowear). Using teeth from both adult and nonadult individuals, we first established categories of dental macrowear patterns and sorted individuals within them. We then made replicas of the teeth from 27 individuals having both typical and atypical dental wear and performed metrology by noncontact profilometry on a reflected light microscope. We then calculated each tooth's surface roughness (Sa) and collected qualitative observations of teeth within each macrowear category. Our findings show no macrowear or microwear pattern exclusive to sex or age group. Likewise, there are no statistically significant differences (p < 0.05) in Sa between adult males and females, and sampled nonadults fall within two standard deviations of the pooled adult means. The microscopic surfaces of all teeth show a wide variety of textures on the occlusal surfaces, including wavy striations, deep parallel striations, globular pitting, and newly described rectangular pits. These results indicate that individuals used their teeth as a third hand while manipulating objects and that children also participated in these activities. Due to the similarities in dental wear between Ashkelon and other coastal populations, we conclude that the observed wear patterns arose from the performance of specialized tasks for a marine-based economy.