Craniodiaphyseal dysplasia

Craniodiaphyseal dysplasia (also known as CDD or lionitis) is an extremely rare autosomal recessive bone disorder that causes calcium to build up in the skull, disfiguring the facial features and reducing life expectancy. The calcium deposits decrease the size of cranial foramina, and can also decrease the hole in the cervical spinal canal. In the few cases recorded, most of the sufferers died in childhood. Among the medical signs are dacryocystitis, seizures, mental retardation, and paralysis, each of which is a complication resulting from the diminutive foramina.

Peter Bogdanovich's 1985 film Mask drew public attention to the case of Roy L. "Rocky" Dennis, an American boy who died of the disorder in 1978.

In the American medical television series comedy-drama Grey's Anatomy episode "Yesterday", a teenage boy is depicted with lionitis.