Large bump left in lip after receiving stitches inside the mouth?

About 3 months ago, I was hit in the face with a softball and had a large laceration in my mouth. I went to the emergency room and got stitches inside my mouth behind my upper lip. Although it healed fine, I am left with a rather large lump at the site of the laceration that is irritating and slightly painful to the touch and when it touches my teeth. I was wondering what kind of doctor I would need to see to potentially dissolve it or get it removed.