cranker sores

Mouth Sores: What Is A Canker Sore?

Did you know our mouths can develop sores? The most common sore we hear and see occurring in our mouth is a cold sore; however, there are other sores which can appear in our mouth. We’ve mentioned in a previous article about the various mouth sores that can develop in our mouth, and we will be going into more detail on what is a canker sore.

Canker Sore

Medically referred as aphthous ulcers, are small, round or oval lesions which affect the softer parts of the mouth such as the tongue, soft palate, cheeks, or inside the lips. They form in the shape of an oval with a white or yellow center and a red border that can be painful when eating or talking.

There are three main categories canker sores can be divided into.

  • Minor Aphthous Stomatitis – are the most common form of the canker sore affecting more than people. They are usually small with red oval edged. They heal within a week or two.
  • Major Aphthous Stomatitis – are broader and deeper sore, more severe than a minor canker sore. They are painful and often leaving a scar after they heal. Major canker sores last longer than two weeks.
  • Herpetiform Canker Sores – although it is uncommon, it’s when there is a cluster of ulcers of 10 or more, but can form into one larger ulcer. They heal within one or two weeks without scarring.   
  • Canker sores are nothing like cold sores. They are not contagious and don’t affect the surface of the lips. They are sores which are limiting since they can only last to one or two weeks.


Although there can be factors which contribute to the development of canker sores, the cause of why we develop this sore is unknown. There have been links to being genetic within a family with a history of aphthous ulcers and allergies.

However, there are other factors associated with triggering canker sores. Some of these risk factors include

  • Minor injury to the mouth
  • Food sensitivities
  • Allergic to dental product components
  • Nutrient deficiencies (vitamin B-12, iron, or zinc)  
  • Hormonal changes
  • Stress
  • Medical conditions

Even though the cause is unclear, keeping track of when you break out with a canker sore can help determine if it is related to an allergic reaction from food ingredients or dental product components.

Visiting the Doctor

Usually, canker sores heal on their own within the one or two weeks span, but if they persist for more than two weeks, then it might be necessary to consult with your doctor. You should see a doctor when

  • Persisting sores lasting more than two weeks
  • Having more than one canker sore in a month
  • Gets worse
  • Experiencing severe pain
  • Have additional symptoms (fever or rash)

If you see your sores are not getting better or healing within the expected time frame, consult with your dentist or doctor for further recommendations and treatment.

There is no cure to canker sores, but you can help reduce factors associated with causing canker sores like watching what you eat and lowering or keeping balanced stress levels. Having good overall health can help maintain good oral health, often our dentists can tell if we have underlying medical conditions which affect our oral health. If you have not seen your dentist for your annual check-up, call our offices today at 801-747-8000 to book an appointment.



Canker Sore. Mayo Clinic

Canker Sores. The American Academy of Oral Medicine

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