By what age should the infant's anterior fontanel close?

The closure of the anterior fontanel is an important developmental milestone in infants. The anterior fontanel, located at the top of the baby's head where the skull bones have not yet fused, typically closes between 12 to 18 months of age. This gradual closure allows for brain growth during the first two years of life, as it provides the necessary flexibility for the skull to expand. If the fontanel were to close too early, it could restrict brain growth, potentially leading to complications. Therefore, the timeframe of 12 to 18 months is correct, as it ensures proper development and growth during this critical period in an infant's life.