fontanelles The gaps between the bones of the vault of the growing skull of the baby and young infant that can be felt, as soft depressions on the top of the head, by gentle pressure with the fingers. The front (anterior) fontanelle lies at the junction of the two forehead (frontal) bones and the two side (parietal) bones. The rear (posterior) fontanelle lies between the two parietal bones and the single rear occipital bone. The fontanelles are covered by scalp and skin and allow moulding of the skull during birth. Both have usually closed by about 14 months. There are two other very small fontanelles on either side of the head.