"Teeth" sinks its incisors into a cross-cultural myth known as vagina dentata. Or, as Juno might call it, "Vaggie D." Depending on who you ask (not that you should bring it up in polite intercourse), it is said to represent the male fear of castration and of feminine sexuality in general. It also symbolizes the woman's anxieties about penetration, and/or her desire to devour her mate, who is attempting to fulfill his own bio-mythological destiny by returning upstream to spawn in the womb from whence he originated. (Or, as the movie puts it, "the dark crucible that hatched him.")