Bites of an older baby with teeth are more painful in part due to the fact
that the infant now has more bacteria in his mouth(the kind that hang around
teeth), and bites get infected more easily (more like the traditional human
bite).

These bites are also more painful because the teeth are so sharp.  I have
found that seeking ways other than breastfeeding to practice using the teeth
usually bring wonderful results. It is important that the mother keep aware
of the infant's more subtle cues regarding the messages "I'm not hungry any
more",  "I'm bored","I want to chomp with my new teeth" or "I want your
attention," rather than waiting for the bite to occur!

Fritzi Drosten, RN IBCLC
Piedmont, CA