>>149270689
A caricature is an exaggeration of existing features meant to portray someone in a slightly humorous way. The expression is a separate detail from the exaggerated features. Whether this person was smiling or frowning, the artist would still draw her with big teeth. She does not suddenly have big teeth for no reason just because it would be funny, but because it's the first thing that stands out in observation when you look at her. It's a visual version of observational humor.

This is completely different from cartoon expressions that are a part of a story/scene.