Prosthesis artificial substitute for a missing piece of the body. The artificial parts that are most generally considered as prostheses are those that supplant lost arms and legs, however bone, artery, and heart valve substitutions are normal and artificial eyes and teeth are additionally effectively named prostheses. The term is here and there stretched out to cover such things as eyeglasses and listening devices, which improve the functioning of a part. The medical specialty which deals with prostheses is called prosthetics.
