Calvarial hyperostosis is a benign X-linked disorder that affects only the skull. Symptoms are prominent frontoparietal bones, flat nasal root, short upturned nose, high forehead with ridging of the metopic and sagittal sutures, and lateral frontal prominences. Radiographs of the skull show increased bone thickness at the sagittal suture line and prominent lateral frontal horns. Increased intracranial pressure and cranial nerve entrapment do not occur (summary by Borra et al., 2014).