 Aphthous stomatitis ( also termed recurrent aphthous stomatitis , recurring oral aphthae or recurrent aphthous ulceration ; from Greek : <unk> aphtha , " mouth ulcer " ) is a common condition characterized by the repeated formation of benign and non @-@ contagious mouth ulcers ( aphthae ) in otherwise healthy individuals . The informal term canker sores is also used , mainly in North America , although this may also refer to any mouth ulcer . 
