Archeologists reveal 2,000-year-old skeleton with all teeth dyed black

Archaeologists in Vietnam have uncovered the earliest known evidence of tooth blackening—a cosmetic tradition once widespread across the country—showing that people living 2,000 years ago deliberately darkened their teeth.

The findings come from a study of human remains at Dong Xa, an Iron Age settlement in northern Vietnam’s Red River Delta.

The research, published in Archaeological and Anthropological Sciences, reveals chemical traces on ancient tooth enamel that match the ingredients used in more recent tooth‑blackening practices recorded in Vietnam up to the early 20th century.

A Beauty Ideal With Ancient Origins

For generations, black, glossy teeth were considered an important marker of beauty, maturity and cultural identity in many Vietnamese communities. The practice only declined in the 1900s under the influence of Western aesthetics.

While historic photographs and oral histories confirm how the process worked in recent centuries, its deeper origins had remained unclear.

Past archaeological finds sometimes showed discoloured teeth, but it was difficult to tell whether the staining came from deliberate dyeing or from other long-standing habits such as chewing betel nut—a stimulant plant that leaves red or brown marks on enamel.

Iron Identified As The Key Ingredient

To solve the mystery, researchers analysed three tooth samples from Dong Xa using non-destructive tools. When they scanned the stained enamel surfaces with X‑ray fluorescence and scanning electron microscopy, they consistently detected elevated levels of iron and sulphur.

Lead author Yue Zhang of the Australian National University said the combination strongly suggested the use of iron salts, which are known to react with tannin-rich plant extracts to form a deep, permanent black. “We believe the combined presence of Fe and S signals is a strong indicator of the involvement of iron salts,” Zhang told Live Science.

In modern communities that still blacken their teeth, artisans mix iron-based materials with tannin sources such as certain woods, pomegranate rind or betel-related plants. When exposed to air, this mixture oxidises into a stable black compound that adheres tightly to the enamel. Once applied over days or weeks, the colour can last for life.

A Process That Took Skill—and Patience

Ethnographic records describe Vietnamese tooth blackening as a multi-step ritual: cleaning and roughening the enamel, applying a red undercoat, then layering on the iron‑tannin mixture until the desired shade was reached. The Dong Xa results suggest that the same chemical principles were already being used two millennia earlier.

The team confirmed this by running experimental tests on modern animal teeth, coating them with a traditional iron‑tannate dye. The chemically altered enamel mirrored the composition found in the ancient samples.

A Shift in Cultural Identity During The Iron Age

The emergence of tooth blackening in the archaeological record coincides with a broader period of change in northern Vietnam. Between 500 B.C. and A.D. 50, the region saw increasing access to iron tools, expanding trade routes, and growing cultural contact with southern China—where some early historical texts also mention populations with blackened teeth.

The researchers suggest the custom may have developed as a replacement for an older local tradition: tooth ablation, the ritual removal of front teeth. Blackening provided a similarly visible marker of adulthood or group identity, but without the permanent physical loss.

The Earliest Link Between Ancient Remains and A Living Tradition

Zhang said the Dong Xa evidence provides the strongest connection yet between archaeological remains and the tooth‑blackening practices observed in Vietnam into the 19th and 20th centuries. “To our knowledge, this is the first time archaeologically discovered blackened teeth have been directly linked to modern intentional tooth-blackening,” she said.

The study reveals that long before the era of photographs and written accounts, Iron Age communities in Vietnam were already transforming their appearance using a carefully crafted cosmetic technology — one that would endure for centuries as a visible emblem of cultural identity.

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Reference

Zhang, Y., Wang, Y., Nguyen, V., Iizuka, Y., & Hung, H. (2026). A kingdom with blackened teeth 2,000 years ago: Tracing the practice of tooth blackening in ancient Vietnam. Archaeological and Anthropological Sciences, 18(2), 29. https://doi.org/10.1007/s12520-025-02366-5