pyknodysostosis is a rare bone disease characterzed with short stature,wide fontaneles,small chin,hyperdensity of bones,erosion of tufts of the disatl phalanges,and narrowing of the mandibular angle. pyknodysostosis is inheritted as an autosomal recessive disease and may be seen in both sexes at any age.the patients have normal life span.short stature and bone fractures are their major problems...