What Diseases Are Associated with Premature Closure of the Anterior Fontanel in Infants?

Actually, when children are born, their bones have not fully developed, so there will be a certain gap between the bones of the head, which is commonly known as the anterior fontanel and posterior fontanel. Normally, as the baby grows, the fontanel will gradually heal, but sometimes due to illness or abnormal conditions, early closure of the fontanel may also occur. Early closure of the anterior fontanel is commonly seen in microcephaly or incomplete brain development.

The timing of fontanel closure is the main indicator of skull development. Premature or delayed closure is a sign of abnormal growth and development. In traditional Chinese medicine, the protrusion of the fontanel is called "Xian Tian," the depression of the fontanel is called "Xian Xian," and the delayed closure of the fontanel is called "Jie Lu." Delayed closure of the fontanel is commonly seen in infants with rickets, hydrocephalus, cretinism, and rapid growth.

The fontanel on the top of the head of infants and young children usually closes between 12-18 months. The closure of the fontanel is a window reflecting brain development. If it closes before 6 months, it may indicate microcephaly or incomplete brain development in the child. If it remains unclosed after 18 months, it is considered too late, and such children may have hydrocephalus, rickets, and cretinism. A bulge in the fontanel indicates increased intracranial pressure, which may indicate meningitis, encephalitis, or vitamin A poisoning. A depression in the fontanel may be due to dehydration and malnutrition.

If the fontanel closes early, but as long as the head circumference is still growing, there is no need to panic. If abnormal closure of the fontanel is detected, immediate further examination should be done at the hospital. The fontanel is divided into the anterior fontanel and the posterior fontanel. The posterior fontanel closes around three months after birth, which is a normal physiological phenomenon. Early closure of the anterior fontanel can have an impact on brain tissue development. However, the reason for early closure of the fontanel is unclear, and some say it may be related to excessive calcium intake.

In fact, medically, it has only been found that babies with early closure of the fontanel have faster bone fusion, but the exact reason remains a mystery. Even if some parents control calcium intake, early closure of the fontanel may still occur. The timing of closure of the anterior fontanel varies. The anterior fontanel is located on the top of the head and is the bony suture between the two frontal bones and the two parietal bones. At birth, it is about 1.5-2.0cm in size and gradually increases with the increase of head circumference. It gradually decreases after six months and usually closes between 12-18 months. In some children, delayed closure due to malnutrition may occur until around 2 years of age, which is also considered normal.

Early closure of the fontanel is commonly seen in microcephaly, while late closure is commonly associated with vitamin D deficiency rickets, hydrocephalus, hypothyroidism, etc. A full fontanel is commonly associated with increased intracranial pressure, while a depressed fontanel is commonly associated with severe dehydration and malnutrition.