2,000-Year-Old Skulls Reveal Ancient Vietnamese Permanently Blackened Teeth

Vietnam - Ekhbary News Agency

Ancient Beauty Ritual: 2,000-Year-Old Skulls Uncover Vietnam's Black Teeth Tradition

A groundbreaking archaeological study has illuminated a centuries-old beauty ritual in Vietnam, revealing that ancient inhabitants deliberately blackened their teeth using iron-based compounds. The findings, based on the analysis of 2,000-year-old skulls, not only push back the timeline for this practice but also highlight its enduring legacy in Southeast Asia.

Researchers investigating skeletal remains from the Dong Xa site, an Iron Age settlement (circa 550 B.C. to A.D. 50) in northern Vietnam's Red River delta, discovered unique dental coloration. This ancient practice of achieving jet-black teeth, considered a high standard of beauty in parts of Vietnam as recently as the late 1800s, has now been traced back two millennia.

The study, published in the journal *Archaeological and Anthropological Sciences*, employed non-destructive analytical techniques to examine the tooth enamel. Using X-ray fluorescence (XRF), scientists identified a high concentration of iron oxide in the discolored areas. Further analysis with scanning electron microscopy with energy dispersive spectrometry (SEM-EDS) confirmed the presence of iron (Fe) and sulfur (S) in the ancient enamel samples.

"We believe that the combined presence of Fe and S signals is a strong indicator of the involvement of iron salts," stated lead author Yue Zhang, an archaeologist at the Australian National University, in an email to Live Science. This chemical signature provides compelling evidence for the intentional application of substances to alter tooth color.

The researchers noted that modern tooth-blackening practices often involve a combination of iron-based materials and tannin-rich botanical sources, such as betel nuts (*Areca catechu*). Betel nut chewing, a long-standing tradition across the Pacific and Southeast Asia, naturally stains teeth and gums reddish-brown. However, when tannic acids from plants interact with iron salts and are exposed to air, they produce a distinct black hue.

Drawing parallels with contemporary methods, the study suggests that the ancient process likely required several days or weeks of consistent application of an iron-tannin mixture to achieve the desired intense black color. Once achieved, the blackening was durable, lasting a lifetime with periodic touch-ups to maintain its luster.

"The practice is still observed today, not only in Vietnam, but also more widely across parts of Southeast Asia," Zhang confirmed, underscoring the cultural persistence of this unique aesthetic. While the exact recipes and application methods may have evolved, the underlying chemical principle – the reaction between tannins and iron salts – appears to have remained consistent.

The identification of iron salt and sulfur on ancient teeth serves as a crucial diagnostic marker for purposeful blackening, distinguishing it from natural staining. This research marks the first known instance of connecting archaeologically recovered blackened teeth with modern intentional tooth-blackening practices, according to Zhang.

The study also touches upon the enduring questions surrounding the origins of this practice. Possible explanations include its development as a less extreme alternative to tooth ablation (the ritual removal of healthy teeth) or as a way to enhance the visual effect of betel nut staining. The increased accessibility of iron tools during the Iron Age likely facilitated the widespread adoption of tooth blackening, allowing for the preparation of the necessary dye paste.

This discovery offers a fascinating glimpse into the complex cultural and aesthetic values of ancient Vietnamese societies, demonstrating a sophisticated understanding of chemistry applied to personal adornment that resonates even today. The research continues to explore the social and cultural significance behind this enduring tradition.

Ekhbary News Agency