Turn with added jaw

Skull and Muscles

and another version of the diagram. 

Head Turn Breakdown 1

Taking it in pieces.  The skull drawing is from Goldfinger's anatomy book.  Done in Illustrator. 

Back to Heads

I've been struggling to get the cartoon look out of my general head model. (Previous versions 1, 2)  I used the proportions from Facial Geometry Graphic:  Facial Analysis for Forensic Artists by Robert M. George for this one.

General Model 3/4 view

Had to go back to the less simplified general model to get this to work.  I also did a lot of feeling around, not just measuring.  There are still lots of things wrong.  For the sectional views I used Eliot Goldfinger's Human Anatomy for Artists.