Interesting, not something I would choose to do, but whatever floats your boat. I wouldn't have put that bit at the edge of the chin though.
Also, now that I have had another look your light sources seem to be conflicting. It seems from the face etc that the light source is coming from the top left and down. However, if you look at his back you have a light source coming from the right somewhat (or is the light source supposed to come from almost the perspective we look at and the arm is blocking out the sun from there?)