RESUMO
Progassive hemifacial atrophy is an uncommon and poorly understood degenerative condition characterized by atrophic changes involving the entire one side of the face, head and associated structures and typically appearing during the growth spurts to young adulthood. The condition involves both soft tissues and bone of the affected side. Intraorally the tongue, lips and salivary glands may be involved. Developing teeth may also show incomplete root development deleyed eruption. The couse of the condition is obscure or unknown although speculation has considered trophic malfunction of the cervical sympathetic nervous system, a history of prior trauma has been documented in some cases, although other reports have considered a viral or borrelial infection. It is usualy sporadic but a few familial cases have been reported suggetsting a possible hereditary influence and many investigators believe it to be a localized from of scleroderma. Five cases of Hemifacial Atrophy (Parry Romberg Syndrom) has been reported and discused.