They may start as a bump or bumps that become infected and leave the mouth irritated and sore,sometimes causing a infection to roof of mouth,jaws etc...for a clear picture of what is going on see your medical Dr...good luck to you
What Do Mouth Ulcers Look Like?
Open sores in your mouth. They can be just an ordinary canker sore, but if you are worried about it you should go and see a doctor. They can clarify any issues you are having.