from what i can see it just looks like hyperpigmentation to me. you can try retin-a or glycolic acid nightly to help fade it a bit or you can go the ipl or v-beam route. its all up to you and how much you want to pay and how fast you want it gone.
forgot to mention you could try tca peels too but not too sure how much downtime you would have to devote to that. they arent bad or anything it just looks strange when the skin is peeling.
you would have to go do a plastic surgeon and see what they have to say. they will be able to tell you which treatment or treatments would be best. i would go see at least 3 of them and then make your decision. i dont really see what else you could do besides having it excised but i wouldnt go that route.
I agree with Tracy. It's more a rolling scar, so subcision might help. Some filler (after the subcision) like restylane, perlane, or the new voluma (which is purported to last 18 mo - 2 years) should help to raise it up to the level of the surrounding skin. Fat transfer is supposedly a permanent option (depends on who you ask), but that can be pricey, and not all the fat survives. If it does, it is considered permanent.
Definitely do not do excisions for this. Excisions are more for smaller, deep ice pick scars and since it is near your mouth, the constant movement and tension would probably not help it heal into a nice scar.
No surgery please. Leave your small minor scar alone and forget about it. This one small scar is not anything. It wouldnt even be anything to those with perfect skin. The severity my friend is all in your head. You look like a good looking guy. Get on with your life and ENJOY!!!!!!