Hello, Mouth ulcers are fairly common. Although uncomfortable, they will heal in a few days. Treatment is symptomatic only. Salt water rinsing, gentle care to avoid area, check for vitamin deficiencies and avoid spicy foods. There are some liquid or gel medications that can offer a proteciive coating with an analgesic to offer relief. Stress or trauma can cause these to occur and can reoccur. Commn in the mouth: apthous ulcer. If the area is not resolving and symptoms increase, your concern could include an infected tooth with a fistula. This means the abscess is draining at the spot mentioned. I advise you to have a dental exam for a correct clinical diagnosis. There are multiple medical conditions that can manifest as mouth sores. The range can be from a simple allergic reaction to a cancer.