Most babies’ fontanels should close between 18 and 24 months after birth. Some babies may close a little later, but as long as their weight, length, head circumference and neurological development are normal, there is no need to worry. Parents should not be too concerned about the size of fontanelle, but should continuously monitor the growth of the child’s head circumference. If the growth of the head circumference is normal, there is no problem for the child to close the fontanelle early or late. However, there is a certain time limit for early and late closure, and the average time for fontanel closure is 18 months, but it is normal for it to close between the ages of one and two. If the child’s fontanelle does not close more than two years old, there is no need for parents to worry too much; if it is almost two years old and the fontanelle has not closed, it is time to see a doctor immediately.