I have cuts on the upper right and left side of my mouth along the line where my gums meet my cheek. They sting a lot, especially if I move my cheeks outward at all. Even if I'm just gently swishing water in my mouth, tipping my head to let the water just flow into the cuts via gravity, it stings so much I tear up. I just woke up one morning with these cuts a few days ago, and I'm unsure as to what caused them, since they are too high for me to have bitten to cut myself.