Two months ago I had tooth #31 extracted. The surgeon said it came out "in a thousand pieces"; not an easy job. Pain persisted for a week, then disappeared. Then a week ago I began experiencing renewed pain, more severe. I also noticed a small area that felt like a serrated knife in the inside of the gum behind the extraction site(where my tongue rubs against). Upon close inspection it appears a small section of jawbone has surfaced(or the gum has peeled away). Is this common, and what should I do? Thanks in advance.