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.
- 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.
- Gold Tooth: Usually reserved for greedy villains.
- Birds (and other animals that don't have teeth in real life) are drawn with teeth so that their mouth looks more human-like when they talk.
Toothy Tropes and Idioms:
- More Teeth than the Osmond Family
- The Tooth Hurts (teeth suffering as a subtrope of Anatomy Agony)
- Vagina Dentata (kind of... don't think about it too long.)