**Question:** False about posterior fontanelle: BHU 09

A. The posterior fontanelle closes before the anterior fontanelle.
B. The posterior fontanelle is larger than the anterior fontanelle.
C. The posterior fontanelle is located at the top of the head.
D. The posterior fontanelle is present exclusively in newborns.

**Core Concept:** Fontanelles are small, slightly elevated, and translucent areas found on the skull of infants, representing unfused sutures between the bones. Posterior fontanelle is located at the back of the head and is smaller than the anterior fontanelle (located at the front of the head).

**Why the Correct Answer is Right:** The correct answer highlights two important facts about the posterior fontanelle:

1. The posterior fontanelle does not close before the anterior fontanelle, as both fontanelles close at approximately the same time, usually around the age of 2 years.
2. The posterior fontanelle is smaller than the anterior fontanelle, but not larger.

**Why Each Wrong Option is Incorrect:**

A. This statement is incorrect because the posterior fontanelle does close after the anterior fontanelle. Both fontanelles close around the age of 2 years, but the anterior fontanelle closes slightly earlier (around 1 year) than the posterior fontanelle (around 2 years).

B. This statement is incorrect because the size of the posterior fontanelle is smaller compared to the anterior fontanelle but not larger. In fact, the anterior fontanelle is typically larger than the posterior fontanelle.

C. This statement is incorrect as the posterior fontanelle is located at the back of the head, not at the top. The anterior fontanelle is located at the front of the head.

D. This statement is incorrect because the posterior fontanelle is present in infants and young children, not exclusively in newborns. While it is true that the posterior fontanelle is larger in newborns, it is present in older children as well.

**Clinical Pearl:** The posterior fontanelle (also known as the occipital fontanelle) is a small, round area on the skull of infants and young children, representing the unfused sutures between the bones of the skull. As the child grows and the skull bones fuse, the fontanelle shrinks in size. This process is a normal part of skull development and does not indicate any pathological condition.