Platybasia

Platybasia is a common congenital bone malformation in the craniocervical junction. It is usually asymptomatic when it occurs alone and is often associated with basilar invagination. The floors of the middle cranial fossa, anterior cranial fossa, and clivus are all invaginated into the cranium, causing the cranial base angle to exceed 145 degrees, which is diagnostically significant. Simple platybasia is generally asymptomatic.