Canker Sores: Types And Possible Causes

Canker sores, medically referred to as aphtous stomatitis, are small, round, and painful ovoid ulcers that develop on the inner structures of the mouth, such as on the lips, on the inner surfaces of the cheeks, on the tongue, and even down the throat.

Despite being no bigger than a pencil eraser, a canker sore packs a lot of hurt.

A canker sore sends you wincing with pain when you eat. It sends you wincing with pain when you drink. And it sends you wincing with pain when you speak.


Canker sores are categorised into three types:

Minor sores. Essentially the most common type of canker sore, minor sores grow anywhere from 3 to 10 mm. Minor sores make for around 80% of total canker sore cases. These lesions take up to 2 full weeks to completely heal.

Major sores. Developing within an irregular border of inflamed tissues, major sores grow a diameter larger than 10 mm. This type of oral lesion makes for 10% of all canker sore cases. Major canker sores can take months to fully heal.

Herpetiform sores. Herpetiform sores consist of multiple small sores, each growing at around 2-3 mm. Herpetiform sores sometimes consist of more than a hundred ovoid ulcers. It makes for 10% of all canker sore cases and, despite consisting of multiple small sores, tend to heal without scarring.


The exact cause of canker sore is still yet to be determined. Still, more than a few experts believe that canker sores thrive on a number of possible suspects. These include:

  • Trauma that results from ill-fitting dentures, fractured teeth, and cracked fillings
  • Iron, folate, and vitamin B-12 deficiency
  • Food allergy
  • Smoking cessation
  • HIV infection
  • Coeliac disease
  • Behcet’s syndrome

Dentist In Sunshine Coast

Canker sores typically go away on their own. Canker sores that last for more than 3 or 4 week may require professional dental help.

Your local Sunshine Coast dentist at Smiles Nambour is committed to helping the local community along a path of optimal oral health and general wellbeing. Smiles Nambour offers safe and effective dental care to the local Sunshine Coast community and its surrounding regions.

Same Day Appointment Available, Request it Now! Call us at (07) 5441 4438, or simply by booking an appointment online.