Update on the skull added the jaw and teeth
Very very nice progress!! Also the shading and lighting are well done, good job!
How many teeth does/did he/she have? I´m counting 28.
Yeah my skull has 28 teeth
When you add muscle and eventually skin on top of your skull, you´ll notice that the mouth area feels unnaturally compressed vertically because of that (28 teeth). This is what happens horizontally to your face when you have no teeth (I couldn´t find a front view picture which would have been better): 
Your mouth becomes smaller in height. Something similar happens to the width, when someone has unnaturally few teeth like your skull. Of course if your wisdom teeth are pulled out, you only have 28 teeth aswell, but you still have the space of those 4 missing teeth which adds to the width of your mouth. The point is: if your goal is to sculpt realistic nice looking faces, it is very important to pay careful attention to the amount, size and placement of the teeth and to the curvature of the toothline/jawline.
Keep it up! 
