Ancient Vietnamese teeth dyed black: iron-based paste reveals 2,000-year-old beauty trend
Archaeologists studying 2,000-year-old skulls from Vietnam’s Dong Xa Iron Age site found iron oxide and sulfur in tooth enamel, indicating ancient people dyed their teeth black with an iron–tannin paste—likely using tannins from betel nut. The practice, dating to the Iron Age, was a cosmetic trend that persisted in parts of Southeast Asia and would have required days to weeks of application with periodic touch-ups.