Orthopaedic problems in patients with pycnodysostosis.

Two new cases of pycnodysostosis are reported with emphasis to some findings not discussed in the literature. Mandibular osteomyelitis seems to be a characteristic feature of the disease because of impaired bone vascularity and abnormal dentition. Multiple fractures also occur during the second decade of life. This coincidence may be attributed to increased skeletal growth during this period of life.