What occurs to the fontanelles as a child grows older?

As a child grows older, the fontanelles, which are the soft spots on an infant's skull, undergo a process of ossification and eventually close. Fontanelles are important during infancy as they allow for flexibility in the skull during childbirth and enable rapid brain growth during early development. Over time, the bones of the skull gradually fuse together, replacing the flexible nature of the fontanelles with solid bone. This process typically occurs by the time the child is around 18 months to 2 years old. Once the fontanelles ossify, they become firmly integrated into the structure of the skull, providing both protection and support for the brain as it continues to develop.