At What Age Do Cranial Sutures Close?

Around two years of age, a child's skull bones begin to join together because the sutures become bone. When this occurs, the suture is said to “close.” In a baby with craniosynostosis, one or more of the sutures closes too early. This can limit or slow the growth of the baby's brain.

At what age does the cranium close?

At birth, the sutures decrease in size (molding) and allow the skull to become smaller. In children, the suture enables the skull to expand with the rapidly growing brain. The suture will close and fuse around age 24.

At what age do the sutures of the skull solidify and the fontanelles close?

The posterior fontanelle usually closes by age 1 or 2 months. It may already be closed at birth. The anterior fontanelle usually closes sometime between 9 months and 18 months. The sutures and fontanelles are needed for the infant's brain growth and development.

Maya Lin-Takahashi

Maya Lin-Takahashi

Consumer Tech & Gadget Reviewer

Maya is a hardware enthusiast who tests and reviews smart home devices, smartphones, wearables, and audio gear. She focuses on practical consumer value and build quality.