So I finally got to making a tutorial for drawing mouth's. Here's wahtcha do...
1. I used lisa/marge's mouth because it was easier but the same rules apply to all characters.
2.When the mouth is open the inside lip line is always behind the neck line. Character's like Wiggum don't have outside lip lines because of the fat.
3. The direction of the lip line determines emotion.
4. With the teeth, they form a sort of 1pt. perspective inside the mouth as shown.
5. As layout artist's we don't deal with mouth shapes for dialogue, but I included a few just in case.
6. There is a 'OO' mouth shape as in "You", and a "oooo" mouth shape that's used for when a character is impressed with something.
Anyway, keep it simple and don't be afraid to strecth and squash the shapes.


This is deffinetly going to be handy, like most of your tutorials, however I always seem to have dificulty drawing their mouths right, thanks for drawing this and posting it up here 
