TTmom, you might want to try giving him milk from a cup. I haven't tried it myself, but I've heard anecdotal evidence that breastfed babies are sometimes more likely to take milk from a cup than a bottle. Also, if you haven't already, be sure to try a different nipple. I remember when Linda was young, standing in front of this wall of bottle nipples at Babies R Us, trying to figure out which of them was closest to my own anatomy.
JCT, I'll echo the OUCH. The danger level of nursing always goes up when they get teeth, doesn't it?