 An aphtha ( plural aphthae ) is a non specific term that refers to an ulcer of the mouth . The word is derived from the Greek word aphtha meaning " eruption " or " ulcer " . The lesions of several other oral conditions are sometimes described as aphthae , including Bednar 's aphthae ( infected , traumatic ulcers on the hard palate in infants ) , oral candidiasis , and foot @-@ and @-@ mouth disease . When used without qualification , aphthae commonly refers to lesions of recurrent aphthous stomatitis . Since the word aphtha is often taken to be synonymous with ulcer , it has been suggested that the term " aphthous ulcer " is redundant , but it remains in common use . <unk> is also a non @-@ specific term referring to any inflammatory process in the mouth , with or without oral ulceration . It may describe many different conditions apart from aphthous stomatitis such as angular stomatitis . 
