The skull manifestations of thalassemia include:

• widening of the diploic space
• thinning of the inner and outer tables
• prominent secondary trabeculae (hair on end appearance)
• the occipital bone is spared (lack of haemopoietic bone marrow)

Facial bones:

• hypopneumatisation of the frontal, maxillary and sphenoid sinuses (filled with marrow containing bone)
• ethmoid sinuses are spared as they contain no red bone marrow
• dental malocclusion