Answer
The cranial bones of the cranial skull are separates before and at birth. If his were not so the head of the fetus could not pass through birth canal-- it is too big. However, because the bones are not fused the volume of the cranium can be decreased by compression to facilitate passage of the head. The head of a newly born infant may look abnormal because the the cranial bones have been moved around. However the bone soon assume their normal positions and the skull it expected (normal) conformation. The interosseous spaces in the cranium of the fetus are called fontanels. They are bridged by fibrous membranes. Later, ossification occurs in these membranes and the cranial bones become fused.
The spaces or fontanelles between the cranial bones of the fetus/infant/baby include the following:
the anterior, the posterior, the sphenoid (anterolateral) and the mastoid (posterolateral) fontanelles.
Moat fontanelles ossify by the time the infant is one year old . However, the anterior fontanelle may still be patent at 24 months after birth.
Work Step by Step
The so-called soft spot in infant's skulls is the fontanelle at the juncture of the two frontal and the two parietal bones; it is usually open for two years after birth. The posterior fontanelle is located where the two parietal bones, and the occipital bone meet; it usually closes within the first few weeks of an infant's life.
