Teeth blackening

Teeth blackening or teeth lacquering is a custom in which a person's teeth are dyed black. It was most common in Southeast Asian and Oceanic cultures. It was most common with Austronesian, Austroasiatic, and Kra–Dai-speaking peoples. It was also done in Japan before the Meiji era and in India. Some groups in the Americas have also followed the custom. For example, it is practiced by the Shuar people of northern Peru and Ecuador.
Teeth blackening is usually done during puberty. It was done to help keep the teeth into old age. This is because it prevents tooth decay in ways similar to modern dental sealants. It was seen as a sign of maturity, beauty and civilization. Teeth blackening is often done with traditions of tooth sharpening and dental evulsion. It was also done with other body modification customs like tattoos. Teeth blackening and filing were seen as strange by early European explorers and colonists. 
The practice is still done in some ethnic groups in Southeast Asia and Oceania. It has stopped being done after Western beauty standards were introduced during the colonial era. It is still done by many minority groups in China, Pacific Islands and Southeast Asia. It is seen most often with older women but the practice is still done by some younger women. 
Teeth blackening is commonly confused with the red-stained teeth. betel chewing causes the teeth to be stained red. However, it damages the teeth and gums. Teeth blackening does not cause damage to the teeth.