One of the most common problems of the soft tissues in the mouth ulcers, also called: canker sores, apthous ulcers, or recurrent apthous stomatitis.
The lesion appears as a white spot surrounded by a red border. It is very sensitive, which can make brushing and eating difficult. Spicy and acidic foods or drinks can cause the ulceration to hurt more. Stick to a bland diet and drink plenty of water.
As there is not a cure, some people find swishing with warm salt water or using over-the-counter products help with discomfort.
If you have sores that do not seem to heal, or occur frequently, check with your dentist to rule out systemic diseases.