Teeth (singular tooth) are bony structures found in the mouths of most species. They aid in chewing food and the speaking of their languages.
According to Greek Mythology, teeth from a dragon slain in war, if spread over a battlefield would produce one warrrior per tooth, who would then continue fighting. In 2376, this myth was conveyed to Captain Janeway of USS Voyager by her first officer Chakotay in the presence of Gedrin, a member of the Vaadwaur species. He was relating the dragon's teeth and their hidden potential to a long dormant cache of armed ships Gedrin had led them to. (VOY: "Dragon's Teeth")
In the Ferengi and Klingon cultures, teeth are sharpened with a tooth-sharpener. (DS9: "Little Green Men")
The Cardassian Bureau of Identification collects a tooth (the first molar) from all citizens of the Cardassian Union at the age of ten. It also collects the molars of non-citizens caught up in the Cardassian legal system. (DS9: "Tribunal")
In 2293, shortly before he was assassinated, the Klingon Chancellor Gorkon used a large tooth from an unknown lifeform as a staff. (Star Trek VI: The Undiscovered Country)
Odo has no teeth, as he informed Makbar, the Chief Archon at Miles O'Brien's trial on Cardassia in December of 2370, when fulfilling the role of O'brien's nestor during the proceedings. (DS9: "Tribunal")