Assertion: mastoid process | /r/HasProperty | undeveloped
Facets:
value: at birth
type: TEMPORAL
value: in the newborn child
type: LOCATION
Source sentences:
text: It is undeveloped in the newborn child and grows only as a result of the pull of the sternomastoid muscle (also called the sternocleidomastoid), as the child moves his or her head.
text: The mastoid process is underdeveloped at birth.