Canker sores, also called aphthous ulcers, are small, painful sores inside the mouth that typically appear on the inner cheeks or lips, at the base of the gums, or on or under the tongue. Children as young as 2 years of age can get canker sores, but most commonly affect people between the ages of 10 and 40, and present more often in females. Learn more in our Dental Topics page.
A canker sore usually appears as a round yellow or white open ulcer surrounded by a red border, or “halo”. Canker sores can occur as a singular ulcer or in small clusters. The most common canker sores are small (minor aphthous ulcers), less than 10mm in diameter, and heal within 7-10 days, leaving no residual scar. Major aphthous ulcers, which are less common (1 in 10 cases), are larger than 10mm across and can last for several months. These canker sores, which are more painful, can leave scars and make eating and talking difficult.
Canker sores often recur after the patient has experienced the first episode and recurrences tend to lessen with age. Canker sores do not generally need medical treatment and are not contagious like fever blisters (cold sores) are. Fever blisters appear on the outside of the mouth/lips and are caused by a virus.
What Causes Canker Sores?
The exact cause of canker sores is not known, however, several factors are believed to contribute to the development of aphthous ulcers. Contributing factors include:
- Emotional stress: Studies show that students experience more incidences of canker sores during higher stress periods, such as exam times.
- Diet: Patients with diets low in iron, vitamin B12, and folic acid tend to develop canker sores more often.
- Allergies: Food allergies can irritate the mouth lining.
- Mouth injury: Brushing the teeth too aggressively, biting the side of the cheek, eating extremely rough or crunchy foods, or drinking hot liquids can injure the inside of the mouth or the tongue. Irritation from orthodontics can also create canker sores.
- Sour or spicy foods: Foods with high acid content can damage the sensitive lining inside the mouth.
- Sodium lauryl sulfate (SLS): Sodium lauryl sulfate is an ingredient found in many toothpastes, as well as mouth rinses, which can be an irritant in some cases. Using a toothpaste without SLS may help reduce canker sore recurrence.
- Heredity: Canker sores can run in family history, so some occurrences may be genetically influenced.
- Weakened immune system: Recurrent aphthous ulcers may be a sign of an immune system problem and may require medical treatment.
- Hormones: Changes in hormone levels, which can occur in females prior to the menstrual cycle, can contribute to canker sores.
- Certain medications: Some medicines are believed to be possible factors in developing mouth ulcers.
If your child is experiencing recurring canker sores (aphthous ulcers) or you would like more information about Treating Canker Sores (Aphthous Ulcers), please contact our office for an appointment with one of our pediatric dentists.
At Kids Dental, we offer comprehensive, family-centered pediatric dental care in a child-friendly nurturing environment. If you are looking for a place to call your dental home, please schedule a consultation with one of our pediatric dentists by completing an Online Appointment Request or calling either office.