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"F" is for "Fontanel"

In this installment of our "ABC" series, we discuss a normal newborn feature...the fontanel (or fontanelle)!

These are commonly referred to as "soft spots". They are on the top of your infant's head and indicate where the skull bones have not yet fused together. This is a normal and healthy presentation at birth! As your baby ages, they will slowly come together and form sutures.

"The six fontanelles are the:

  • Anterior fontanelle x 1

  • Posterior fontanelle x 1

  • Mastoid fontanelle x 2

  • Sphenoid or sphenoidal fontanelle x 2

The anterior fontanelle is the largest. This diamond-shaped soft spot is located between the frontal and parietal bones. At this point in life, the frontal bone is not a single bone but consists of a left and right bone that must grow in size and fuse as the brain increases in mass.

The position of this largest soft spot can be easily seen on a newborn."

Fontanels serve three main purposes:

1. These "soft spots" allow for baby's head to mold and adjust as they descend through the birth canal. In other words, the fontanels help your baby squish through on it's way out. Your baby is perfectly designed to work with your body during labor!

2. They create space for rapid brain growth during those first two years of life.

3. They also serve as a warning signal! If the fontanel is depressed/sunken in, that can mean your baby is dehydrated. Contact your doctor if this happens!

The fontanels will gradually close over time. From birth to fully closed takes roughly three years. Your pediatrician or family doctor will check this progress during your regular check-ups, and will discuss any concerns during those appointments.

Want to see a more in-depth presentation about the anatomical features and changes that an infant skull will go through? We found this video to be informative and easy to follow!

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