Aphthous stomatitis 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. Stomatitis is also a non-specific term referring to any inflammatory process in the
Supernumerary body part considered to have lost much or all of their original function through evolution. These body parts can be classed as additional to the required functioning of the body. In human anatomy the vermiform appendix is sometimes classed as a vestigial remnant. Prosthesis is an artificial extension that replaces a body part, and cybernetics is the study of computer technology in relation to organisms which can include replacement or additional body parts. Body integrity identity disorder (BIID) is a psychiatric disorder in which a person thinks that they have one or more additional limbs than they should, despite having two arms