Tags: Disease.
A mouth ulcer (also termed an oral ulcer or a mucosal ulcer) is an ulcer that occurs on the mucous membrane of the oral cavity. More plainly a mouth ulcer is a sore or open lesion in the mouth. Mouth ulcers are very common occurring in association with many diseases and by many different mechanisms but usually there is no serious underlying cause. The two most common causes of oral ulceration are local trauma (e.g.
