Fontanel: what is it and what is it for?

 All babies come into the world with a soft area on their forehead: the fontanelle. This is an extremely important gap for the healthy growth of the baby.

Most parents react with fascination and infinite care the first time they run their fingers over that small gap on their baby's forehead: it is the major fontanel. This rhombus-shaped area measuring two by two centimeters is easy to perceive by touch, you can even notice the beating of blood. But it is only one of the baby's six fontanels: there is a second, triangular and smaller one, on the back of the neck and four others, tiny and barely noticeable, distributed in pairs on the sides of the skull and behind the ears.

Birthing crumple zones

These small gaps are the union areas between the bone plates that make up the skull. The bones only grow together completely after a few years. And why don't they do it before delivery? Well, because, during evolution, human beings learned to walk on their two legs and their hips became smaller to be able to maintain an upright posture. But the babies' natural outlet also became smaller. The fontanels were the solution: these soft areas make the baby's skull very elastic and deformable.

During childbirth, the bony plates can come together and often even overlap, allowing smooth passage through the birth canal. It is this pressure that causes the head of newborns to usually have a slightly pointed or deformed appearance, although everything returns to normal after a few days. Fontanelles  also have two other very important functions :

Different opening periods

The fontanels begin to close from the sixth week of life. While the small and lateral fontanels are completely closed by the end of the first year, the large fontanel located on the forehead can take up to 24 months to do so. Babies have different builds, sizes, and weights; Likewise, the fontanelles close at different speeds in each case. Some babies may no longer notice them after a year while others may still be there until their third birthday.

It is not necessary to keep them in cotton

Leaving aside the fact that you always have to be very careful with a baby's head, the truth is that fontanels do not pose a high risk of injury to the child. The tough skin of the head and the brain membrane offer sufficient protection until the fontanels are closed with connective and cartilaginous tissue. The bone plates of the temples do not completely fuse with bone tissue until after about 20 years.

Windows to the brain

The greater fontanel of babies makes the work of doctors easier. This “window” allows them to study the brain with the help of ultrasound in a quick and easy way. In this way, they can quickly detect malformations, hemorrhages or tumors. To do this, the doctor places the ultrasound emitter directly over the major fontanel or moves it along the lateral suture of the skull. The baby does not feel any pain.