I have had on my left inside my inner check a small flap of skin, I thought when I first noticed it I had bite my check, but there was no blood , I ignored it and I thought it would go away or the skin would just grow back into the rest of my tissue , but every now and then it really hurts and is tender, I can move the skin with my tounge. It has gotten bigger, and I hope it is something that is common, I know the possiblilites of it get infected, but I just want to know what it is?