What Is a Mouth Ulcer? A mouth ulcer is a small, shallow open wound (or sore) in your mouth that can make eating and talking uncomfortable. They’re also known as canker sores. Mouth ulcers are common ailments that affect many people at some point in their lives. It is not a teeth or gum relatedContinue reading “Mouth Ulcers : Causes, Symptoms, Treatments and Types”