First project ; Wolverine bust

O.k here is my first ever Blender project, I need advice on how to do the mouth in a snarl. And helpfull sugestions on how to improve what I have done so far would also be most welcome. I am sending this in again because the jpegs seem to have vanished from the first one I sent.


Just select the vertices on the outerline of the mouth and extrude and size inwards couple of times. Then just adjust the vertices on correct position.