Mary-Ann smiled. Notwithstanding her black decayed teeth there was in her smile something sweet and touching.
玛丽—安笑了。 尽管她有一口黑蛀牙,但是她的笑容还是显得很甜美动人。
Engvid超级外教Ronnie-口语
So if this is a picture of my black teeth, I have a pink tissue above my mouth -- or in my mouth -- that surrounds my teeth like this, and these are called " gums" .
Ohaguro(お歯黒) is a custom of dyeing one's teeth black. It was most popular in Japan until the Meiji era. Tooth painting is also known and practiced in the southeastern parts of China, Pacific Islands and Southeast Asia. Dyeing is mainly done by married women, though occasionally men do it as well. It was also beneficial, as it prevented tooth decay, in a similar fashion to modern dental sealants.