Cranial sutures are fibrous bands of tissue that connect the
bones of the skull. Fontanelles; Sutures - cranial An infant's
skull is made up of six separate cranial bones (the frontal
bone, the occipital bone, two parietal bones, and two temporal
bones). These bones are held together by strong, fibrous,
elastic tissues called cranial sutures. The spaces between the
bones where the sutures are (sometimes known as "soft spots")
are called fontanelles. They are a part of normal development.
The cranial bones remain separate for about 12-18 months. They
then grow together (fuse) as part of normal growth. They stay
fused throughout adulthood. Two fontanelles are usually seen on
a newborn's skull: one on the top in the middle, just forward of
center; and one in the back in the middle. Like the sutures,
fontanelles gradually become closed, solid, bony areas. The
posterior fontanelle (in the back of the head) usually closes by
the time an infant is 1 or 2 months old, or may already be
closed at birth. The anterior fo