Paget's disease (osteitis deformans) and osteoporosis represent the co
mmonest systemic bone disorders. Clinically Paget's disease may be mon
o-, or polyostotic, and is characterized by excessive and disorganized
formation and resorption of bone. It may affect any of the facial bon
es, most notably the skull and the jaws. A case is described in which
the only symptomatic manifestation of Paget's disease was mandibular p
rognathism. The pathogenesis, aetiology, and management are discussed.