Toothy Issue

Or the use of teeth in fiction.

Most of the time, you get Hollywood Teeth- everybody has lovely straight pearly whites, even where this is unlikely (more on the lack of orthodontics front than access to sweets).
 * This is occasionally subverted for realism's sake: in the Broadway version of Les Misérables, the characters have horrible teeth, which makes sense since most of them are, well, poor.

However, teeth can have other connotations.
 * Missing teeth can be seen on roguish or villainous sort of characters, like Fagin.
 * Or, conversely, on cute little kids who are losing their baby teeth.
 * Or as a comedic effect.
 * Vampireth have fangth.
 * Someone's teeth may shatter in a cartoon situation.
 * British Teeth - Yellowing, busted piano keys may best describe the teeth of the British if this trope is to be believed.
 * Yellow Peril: Villainous Asians have crooked teeth.
 * Cute Little Fangs may express a character's hyperactivity.

Toothy Tropes And Idioms:
 * More Teeth Than the Osmond Family
 * Vagina Dentata (kind of... don't think about it too long.)