Certified Pediatric Nurse (CPN)

When does the posterior fontanel typically close?

1. 9 months

2. 12 months

3. 2-3 months

4. 6 months

The correct answer is: 2-3 months

The posterior fontanel typically closes between 2 to 3 months of age. This closure occurs relatively early in an infant's life, as the posterior fontanel is smaller and less significant in size compared to the anterior fontanel, which closes later, usually between 12 to 18 months. Understanding the timing of fontanel closure is crucial in pediatric nursing as it can indicate normal growth and development of the infant’s skull. Closure of fontanels helps to protect the underlying structures of the brain while allowing for necessary growth. Observing the timing of these closures provides healthcare providers with important information about the infant's development and can alert them to potential issues if closures happen too early or too late.