Of these Janie #2 and #4 stood out to me the most.

You need to move the model away from the background about 4-6 feet to get the shadown dropping off and also blur the background.

When taking images, turn the head a little towards the light source so you can see only the jaw line and not the ear on one side.

Certainly a good start. What about putting the teeth back in the mouth, that would be a fun exercise as well.