Mouth sores can be painful, annoying and unsightly.
Some appear inside the mouth – on the gums, tongue, lips, cheeks or palate (roof of the mouth). Others, like cold sores, can appear outside the mouth, such as on and around the lips, under the nose and on the chin.
Mouth sores can be caused by oral cancer or bacterial, viral or fungal infections. Some other causes include:
- Irritations, such as dentures that no longer fit properly and rub against tissues.
- Loose orthodontic wires or the sharp edge of a broken tooth or filling.
- Extreme sensitivity to ingredients found in some toothpastes or mouth rinses.
- Medication, cancer treatment side effects or reaction to therapy.
- Certain specific skin, oral or systemic diseases.
Although there are many types of mouth sores, the most common are canker sores, cold sores, leukoplakia (a thick white or gray patch) and candidiasis or thrush (a fungal infection).
Some people may experience occasional discolored, painless spots in their mouth. Most are harmless and will disappear or remain unchanged. However, some sores or spots can be serious and need the attention of your dentist or physician. For example, oral cancer may not be painful at first, but it can be deadly. That’s why regular dental checkups are important. Have your dentist examine any mouth sore or spot that fails to heal within two weeks.
Canker sores appear inside the mouth. They usually are small ulcers (minor aphthous ulcers) with a white, yellow or gray center and a flat red border. Rarely, canker sores can be very large (major aphthous ulcers) with a raised border. There may be one or several ulcers and they recur at varying periods of time.
A canker sore usually begins as a red spot or bump. It may produce a tingling or burning sensation before other symptoms appear. Canker sores are painful. Fortunately, most canker sores heal spontaneously in 7 to 10 days.