A few weeks ago I had the opportunity visit a hill tribe in Mae Sa, near Chiang Mai. Thanks to the Thai driver we hired, I was able to chat a bit with the locals and ask questions.
This woman was from the White Karen hill tribe (Ka Nyaw Wah in Karen), an ethnic tribe residing primarily in southern and southeastern Burma, although many can be found in Northern Thailand as refugees. She was 79 years old and still very cheerful and active. She was weaving a big piece of traditional cloth that would take her 2-3 weeks to finish and would be sold to tourists in the village. She lived in the village for years, in a small wooden hut with no electricity or running water.
The red paste she had around her mouth is a kind of herb they chew to make the teeth healthier. Apparently it works well, 79 years old and still had all her teeth! (even if they look red).