Diachronic Trends in Dental Hygiene Over the Last 2000 Years in Milan, Italy: An Exploratory Study

Background: Oral health is a multi-factorial condition influenced by diet, hygiene and sociocultural habits and its historical evolution can be traced through the bioarchaeological analysis of dento-skeletal remains, offering unique insights into past lifestyles and public health trends. Aim: This observational study aimed to explore diachronic trends in oral health and hygiene over the last 2000 years in Milan, Italy, through the bioarchaeological analysis of skeletal remains from four historical periods (Roman Era, Early and Late Middle Ages, Modern Era). Methods: Forty individuals (equally represented by biological sex and age-at-death) were examined for dental calculus, wear, caries, and bone resorption. Data were collected using standardised clinical indices (OHI, BEWE, ICDAS, Black's classification and bone resorption) and statistically analysed to identify sex-based and diachronic differences. Results: A progressive decline in dental calculus and wear was shown, reflecting dietary transitions and improved hygiene practices. Caries prevalence varied across periods, peaking in the Modern Era, while bone resorption varied little across periods. Notable sex-based disparities were observed in the earlier periods, especially regarding calculus, but diminished over time. Conclusions: Skeletal remains provide valuable insight into long-term oral health evolution and emphasise the relevance of archaeological evidence for contemporary public health perspectives.