Craniopagus parasiticus: a case report of a parasitic head protruding from the right side of the face.

An extremely rare case of parasitic head protruding from the right side of the face is presented. It differs from all the other cases previously reported in the literature. The patient had a parasitic head with an abnormal brain, two eyebrows, two underdeveloped eyes, nose, mouth, 12 teeth, a tongue and plenty of hair. The parasitic head was excised. The nature of the embryological abnormalities is discussed and the literature of polygnathism reviewed.