Useless fact
What is the soft spot on a baby's head called?
The soft spot on a newborn baby's head where the skull bones have not yet fused is anatomically called a fontanelle.
The word fontanelle comes from the Old French word fontenele, meaning a small fountain or spring, which likely refers to the visible pulsing of the blood vessels beneath the soft spot. During birth, these flexible gaps between the skull bones, known as sutures, allow the baby's head to compress slightly to pass through the birth canal safely. They also allow the brain to expand rapidly during the first year of life. Typically, a baby has several fontanelles, with the two most prominent being the anterior fontanelle on top of the head and the posterior fontanelle at the back. The smaller posterior fontanelle usually closes within two to three months after birth, while the larger diamond-shaped anterior fontanelle takes much longer, typically closing completely between twelve and eighteen months of age. Pediatricians regularly check these soft spots during routine checkups, as an abnormally sunken fontanelle can indicate dehydration, while a bulging one might suggest increased pressure inside the skull.
Why this is true — The term fontanelle is the standard anatomical and medical name for the soft spots on an infant's skull, as documented in medical dictionaries and encyclopedias.
Sources
- Fontanelles - infant National Library of Medicine