caput quadratum
ca·put qua·dra·tum
Aetiology Untreated vitamin D-induced rickets, which causes a thickened outer table with permanent enlargement of the head, congenital anemia—e.g., thalassaemia with massive hematopoiesis in an expanded marrow space, aka ‘hot cross bun skull’—and others—e.g., conditions associated with ‘gargoyle’ facies, acromesomelic dysplasia of Maroteaux, anhydrotic ectodermal dysplasia, craniometaphyseal dysplasia of Pyle, frontodigital syndrome, Kenney’s tubular stenosis syndrome, basal cell nevus syndrome, Taybi syndrome, thanatophoric dwarfism, and AIDS embryopathy