Fontanelle dysplasia

There are two main fontanelles. One is located at the anterior part of the top of the head, formed by the junction of the anterosuperior angles of the two parietal bones and the frontal bone. It typically closes between 1 and 1.5 years of age and is called the anterior fontanelle. The other is the posterior fontanelle, formed by the junction of the parietal and occipital bones, located at the posterior part of the top of the head. It is usually very small or already closed at birth, and closes at the latest between 2 and 4 months after birth. Fontanelle dysplasia includes premature fontanelle closure, delayed fontanelle closure, and a head circumference significantly smaller than normal.