The fontanelles on the top of an infant’s head are divided into anterior fontanelles, which generally close within a year and a half after birth, and posterior fontanelles, which generally close within six to eight weeks after birth.
The anterior fontanel of the infant’s head is a diamond-shaped gap formed by the frontal and parietal bones and usually closes within one and a half years of age. Note that early closure can lead to head hypoplasia, while rickets and congenital hypothyroidism can lead to late closure of the fontanel and require prompt intervention. The posterior fontanel, a triangular gap formed by the parietal and occipital bones, closes early, within six to eight weeks.
It is important to note that the fontanels of infants are fragile and must be protected from bumping into them. It is also important to look for sunken or protruding fontanelles, as they may protrude with increased intracranial pressure and may be sunken with conditions such as dehydration.
It is advisable to seek medical attention as soon as the baby is in any discomfort to avoid serious consequences.