say, im not sure, you probably got all the answers you need, but i thought i would post anyway. :)
congratulations for sticking with your decision to keep breastfeeding until your baby is a year old! i aimed for that too, and decided to keep nursing after that; my son self weaned at 20 months. i was disappointed! LOL.
anyway, what i did with him was to immediatly end the feeding. you can do that one of 2 ways, you can say "ouch! hurt mama! no!" and put him down, or do what i did, just put him down and i think i said something like "ok, you arent hungry anymore are ya?" - it worked. he NEVER did it again. worked like a charm! :P
good luck! and im so glad that you are breastfeeding - it truly is the most perfect food for your baby! :) breastmilk changes as time goes by; its perfectly suited for her specific age, even when shes older! :) its awesome!
you can also use it on owies too. i put some on my son's head when he scraped it on our porch... it healed right up, no scab, no scar!
if this is a teeth rubbing issue, make sure your nipple gets far enough in his mouth. sometimes another way to get baby to loosen their mouth is to pull him toward your breast; this forces him to open his mouth more. :) try that!: )