When does the posterior fontanelle close?
A.
3 to 6 months.
B.
6 to 9 months.
C.
9 to 12 months.
D.
2 to 3 months.
The Correct answer and Explanation is:
The correct answer is D. 2 to 3 months.
Explanation:
The posterior fontanelle is one of the soft spots on a newborn’s skull where the cranial bones have not yet fused. These fontanelles are crucial for the infant’s brain growth and development, as they allow the skull to expand as the brain grows. The posterior fontanelle is located at the junction where the two parietal bones meet the occipital bone at the back of the skull.
The posterior fontanelle is generally triangular in shape and smaller than the anterior fontanelle, which is located at the top of the head. The closure of fontanelles occurs at different times, with the posterior fontanelle closing much earlier than the anterior one. Typically, the posterior fontanelle closes between 2 to 3 months of age. This early closure is due to the smaller size and reduced need for skull expansion in that area as compared to the anterior fontanelle.
Importance in Nursing Practice:
In pediatric care, monitoring the closure of fontanelles is crucial because it can provide insight into a child’s development and detect potential abnormalities. For example, delayed closure of the fontanelles may be associated with conditions like hypothyroidism, Down syndrome, or increased intracranial pressure. Conversely, premature closure (craniosynostosis) can lead to abnormal head shapes and may require surgical intervention to prevent brain growth restriction.
The normal timeline for fontanelle closure, especially the posterior fontanelle, is important for nurses to recognize as part of routine well-baby assessments. Understanding the timing helps healthcare providers reassure parents when closure occurs within the normal range and prompts further evaluation when it does not.
In conclusion, the posterior fontanelle typically closes by 2 to 3 months, and its monitoring is a key aspect of pediatric health assessments.