Secrets of a Top Philadelphia Dentist: Canker Sore Treatment ‘Tis the season for stress, sickness and as a result, mouth sores. Specifically, we are talking about canker sores, which are not to be confused with cold sores. To clarify, canker sores are small ulcers that appear inside of your mouth. Symptoms of canker sores include: Tingling or burning in an area of your mouth before sores appear. Painful sore(s) inside of your mouth, specifically inside of your cheeks, as well as your tongue ...more