What are the 4 fontanelles?

What are the 4 fontanelles?

The fontanelles include:

  • Anterior fontanelle (also called soft spot). This is the junction where the 2 frontal and 2 parietal bones meet. The anterior fontanelle remains soft until about 18 months to 2 years of age.
  • Posterior fontanelle. This is the junction of the 2 parietal bones and the occipital bone.

What is the largest fontanelle?

The anterior fontanel is the largest and most important for clinical evaluation. The average size of the anterior fontanel is 2.1 cm, and the median time of closure is 13.8 months.

What are the 6 fontanelles?

Structure and Function

  • Anterior Fontanelle. The anterior fontanelle is the largest of the six fontanelles, and it resembles a diamond-shape ranging in size from 0.6 cm to 3.6 cm with a mean of 2.1 cm.
  • Posterior Fontanelle.
  • Mastoid Fontanelle.
  • Sphenoid Fontanelle.
  • Third Fontanel.

At what age are the fontanelles closed?

The posterior fontanelle usually closes by age 1 or 2 months. It may already be closed at birth. The anterior fontanelle usually closes sometime between 9 months and 18 months. The sutures and fontanelles are needed for the infant’s brain growth and development.

What are the two largest fontanelles?

The posterior fontanel is triangular and lies at the apex of the occipital bone. The largest fontanel, the anterior, is at the crown between the halves of the frontal and the parietals.

Can a baby’s soft spot be too big?

It is normal for infants to have these soft spots, which can be seen and felt on the top and back of the head. Fontanelles that are abnormally large may indicate a medical condition. A wide fontanelle occurs when the fontanelle is larger in size than expected for the age of the baby.

What are the two largest Fontanelles?

What happens if the fontanelle closes too early?

When this suture closes too early, the baby’s head will grow long and narrow (scaphocephaly). It is the most common type of craniosynostosis.

What happens if the soft spot closes too soon?

When a suture closes and the skull bones join together too soon, the baby’s head will stop growing in only that part of the skull. In the other parts of the skull where the sutures have not joined together, the baby’s head will continue to grow.

When does the fontanelle reach its maximum size?

Finally by the second decade of the child’s life the brain reaches maximum size and the sutures get fused to the bone growth forming a whole skull structure. Doctors can actually trace the growth and development of the baby by feeling the cranial sutures. The fontanelle must feel firm and be flat when touched.

How many fontanelles are there in a baby’s skull?

A baby has six fontanelles that consist of membranous tissue in the areas where certain adult skull sutures are found. Fontanelles allow the skull to pass through the birth canal and also provide a means of expansion as the brain grows.

When do fontanelles need to be kept clean?

That way both anterior and posterior fontanelles are afforded protection from the cold. The skin of the skull should be kept clean to prevent infection. The cranial bones of most babies are sealed by the time they reach about 18 months of age.

How does Fontanelle help save a baby’s life?

Increased pressure in the brain, most commonly due to hydrocephalus (water on the brain). When the brain is unable to drain away excess cerebrospinal fluid or leaked blood, fontanels can save a baby’s life. While an adult skull cannot change shape once fused, soft spots allow a young baby’s skull to expand.