-Mod edit: Removed image for incorrect crediting, and because the image is nonstock-

So, in this picture, you get both the dogs outer design and interior design. The dogs jaw is built to hold its teeth in eeven rows that fit perfectly. The front top teeth come over the bottom slightly. On the outide, you have the nose, and lips of the dog to go over the teeth. Because they are built in relatively straight lines, you get a sort of "box" shape. And since the top are farther forward, the bottom jaws skin is naturally back a little more.

(picture is not mine, belongs to blackwolfgsd.com)