Occipital osteodiastasis due to birth injury

**Definition:** Occipital osteodiastasis (OOD) is a form of birth injury characterised by a tear along the innominate (posterior occipital or supraoccipital-exoccipital) synchondrosis with separation of the occipital squama from the lateral or condylar parts of the occipital bone.

**Long definition:** Occipital osteodiastasis is a form of birth injury characterized by a tear along the posterior occipital synchondrosis with separation of the lateral or condylar parts of the occipital bone. This is usually attributed to excessive pressure exerted over the subocciput during delivery resulting in forward and upward displacement of the anterior margin of the occipital squama into the posterior cranial fossa. Posterior fossa hemorrhage is one of the complications. There are three forms of occipital osteodiastasis. The first is the classic, fatal form. The second is a less severe variant compatible with survival and the third following birth trauma is seen in the postnatal period.