My son did that too and it drove me CRAZY until I realized he was teething again. Now it's time for the baby front teeth to get loose and the adult teeth to come in, and constant chewing and tugging is the most efficient way to help this along. I had my son chew on a wet washcloth. If the look of this drives you crazy, it can be just in her room, or when she's by herself.
I hope that helps,