Fontanel is a Space between the Cranial Bones of the Fetus
Fontanel (also spelled fontanelle) is a gap between the dermal bones of an infant’s skull covered by tough membranes. It is due to incomplete ossification of the cranial bones and the resulting incomplete closure of the sutures. Newborn babies are born with a fontanelle, which disappears as the bones in the skull fuse; the fusion is complete at around 18 months of age. The front fontanel remains soft until about 2 years of age. The back fontanel, triangular in shape, closes about 2 months after birth. Increased brain pressure may cause a fontanel to become tense or bulge. A fontanel may be soft and sunken if the infant is dehydrated. The presence of fontanelle facilitates safe child birth. (Page 996)
© (From the Book, “Biology for Medical Entrance”, S Chand Publishing, New Delhi, India)