Fig. 1.

Selected radiographs of Patient 2 at 17 years of age, Patient 4 at 8 years of age and Patient 5 at 4 years of age. A diffuse increased bone density is evident. Panel a: Lateral view of the skull (Patient 2 top; Patient 4 middle; Patient 5 bottom). Loss of the mandible angle is present only in Patient 5, which also presents wormian bones. The superposition on the X-ray in the middle is caused by braids (the patient being of Caribbean origin). Panel b: Hand radiographs of Patient 4 (left) and Patient 5 (right). The distal phalangeal tufts are small and this might be considered an early sign of acroosteolysis (but also a normal variant); however no overt signs of acroosteolysis are present, possibly because of their relatively young age. Only the diaphyseal constriction of metacarpals in Patient 5 is suggestive of Pycnodysostosis. Panel c: “Sandwich vertebrae” in Patient 5. The lateral view shows peripheral bone sclerosis with central hypo-densities and a wide anterior notch corresponding to the arterial canal.