Melbourne Smile Clinic

What causes mouth ulcers?

Mouth ulcers can be caused by

Recurrent aphtous stomatitis: This is the most common cause of mouth ulcers that have a tendency to recur for no apparent reason. These are more common in younger people (10-29 yoa). They can lead to small, large or a cluster of ulcers which are quite painful. The  most common underlying cause for recurrent aphtous ulcers are genetic factors, stress and nutritional deficiencies (mainly of iron, folic acid and vitamin B12). Rinsing with salt water can help heal the smaller and less painful ulcers. Otherwise, topical steroid ointment can be helpful and must be prescribed by a health professional. 

Trauma: cheek biting or chewing, rubbing against a sharp tooth/ ill-fitting dentures and piercings, foods that are too hot or hard-textured are all possible causes of ulceration. Usually these ulcers are once-off and disappear once the cause is removed.  

Chemical: Ulcers can be caused by a chemical irritant, such as keeping a tablet of aspirin against a tooth in the hope that it will alleviate a toothache (please note that aspirin must be swallowed for any pain-relief result). Another example is the improper use or application of teeth bleaching gel. These contain high levels of peroxide that when in contact with the mucosa for too long, will lead to ulcerative burns.

Medication-related: Chemotherapy medications used in cancer cause oral ulceration while radiotherapy cause ulcers only when used in the head and neck region. Medications used to prevent transplant rejection also have this effect. It is usually recommended that patients ensure that their dental health is good prior to starting such medical treatments. This is because dental treatment is made more difficult and uncomfortable due to the presence of ulcers in the mouth and there are higher risks of infection.

Infections: Viral infections can cause of recurrent mouth ulcers. For example, first-time infection by the Herpes virus can cause red, sore gums and blisters that rupture to form ulcers. In Hand, food and mouth disease, a different virus is responsible (coxsackier virus). The patient develops malaise and fever and ulcers can appear anywhere in the mouth.

Mucocutaneous and autoimmunce diseases:

Mucocutaneous diseases are disorders directly affecting  the soft tissues of the mouth. The oral soft tissues are hypersensitive and hyper-reactive. An example is Lichen Planus, a rare condition affecting only 1-2% of the population, where manifestations are sloughing and bleeding gums, ulcerations, altered taste and sensitivity to spicy foods. 

Autoimmune diseases include inflammatory bowel diseases such as celiac disease, Crohn's disease and Ulcerative colitis. These can have oral manifestations including mouth ulcers which usually resolve when the underlying disease is treated. Other autoimmune diseases such a Behcet's disease and SLE (systemic lupus erythematous) affect multiple systems in the body, including the oral cavity, leading to ulcerations. 

Reference: Recurrent oral ulceration. Aetiology, classification, management and diagnostic algorith. Elizabeth A. Bilodeau, Lalla R.V. Periodontology 2000 (Volume 80, issue 1, pg 49-60) June 2019

Covid-19 precautions in place: Dental treatment is available for patients who present no Covid-19 risk factors and for whom delaying treatment will lead to negative outcomes. Patients who have tested positive to Covid-19, have been a close contact of a positive case or have been to any listed exposure sites are advised to delay dental treatment until clear of all risks. Patients are kindly asked to check-in using the QR code at reception and to make sure that they do not present any symptoms indicative of possible Covid-19 infection. Patients will need to hand-sanitise and use a disinfecting mouthrinse prior to treatment being provided.