Question
A 23-month-old boy has not fully closed his fontanelle, which is still the size of a soybean. The child’s development in all aspects is normal, and he continues to supplement calcium. What could be the cause of this situation? Will it affect his intellectual development?
Answer
Hello, a late closure of a child’s fontanelle may be due to calcium deficiency, and it is recommended to supplement both vitamin D and calcium. This condition may have some impact on intellectual development. Generally, a newborn’s posterior fontanelle is very small or already fused, and it usually closes by 6 to 8 weeks after birth. The anterior fontanelle is about 1.5 to 2.5 centimeters in diameter at birth and typically closes between 1 and 1.5 years old as the skull bones gradually ossify. Delayed closure of the fontanelle may be related to calcium deficiency or hypothyroidism, and in rare cases, it may be caused by increased intracranial pressure due to hydrocephalus or other reasons. Further medical examination is recommended.