here's what another forumer/breeder said about these sores from another thread:

Quote Originally Posted by Slowcountry Balls View Post
Do you keep him in a rack? I had some snakes show very similar sores on their lower lip, either on one side, or symetrically on both sides. I consulted a veterinarian, and he told me that he saw very similar sores on animals in another collection. He said that the other collection was also kept in tubs in a rack, and that the problem ended up being that there was enough of a gap between the tub and the rack that as the Ball Python tries to explore and escape, it rubs a sore (or two) on the lower lip. When I checked my collection, sure enough, all of the snakes with the sores ended up being active snakes in tubs with a small gap between the top of the tub and the rack. I have shimmed under the front of those tubs and all the sores have healed up.
the gap between the top of the tub and rack may be causing it as the snake try to explore and constantly rubs it while trying to get out. the thread is here - http://ball-pythons.net/forums/showt...est-part/page2 (it's a pix thread tho)