FONTANELLES(ANTERIOR FONTANELLE, POSTERIOR FONTANELLE, SPHENOIDAL FONTANELLES, MASTOID FONTANELLES)

The fetal skull made from parital bones, occipital bone, frontal bones, temporal bones and these bones are connected with each other with sutures such as coronal suture, frontal suture, sagittal suture and lambdoid suture.

FONTANELLS

When two or more suture connects at one point of the fetal skull is called fontanelles.

There are six fontanelles present in the fetal skull

1-ANTERIOR FONTANELLE(BREGMA)

There is a gap which is diamond shape located on anterior portion of fetal skull is called anterior fontanelle.

This anterior fontanelle is formed by joining of the sagittal suture, frontal sutures and two coronal suture.it is measures 3to 4 cm long and wide 1.5 to 2 cm.

Pulsation from cerebral vessel can be felt through it.

Anterior fontanelle is closed after 18 month of birth of baby or when the baby is 18 month old.

2-POSTERIOR FONTANELLE

It is triangular shape gap located posterior part of skull is called posterior fontanelle.

It is the junction where the sagittal suture and lambdoidal suture meet at one point.

It closes 6 to 8 weeks from birth.

3-TWO SPHENOIDAL FONTANELLES

It is situated one on each either side of fetal skull between the sphenoid bone and the parietal bone.it is also known as anterolateral fontanelle.it is closed after 6 month after birth.

4-TWO MASTOID FONTANELLS

It is also paired bone situated one on either side of fetal skull between temporal bones and occipital bone.it is also called posterolateral fontanelle and close between six to eighteen months of age.

SEQUENCE OF FONTANELLE CLOSURE

1- first posterior fontanelle or lambda closes 2to 3 months after birth.

2-next sphenoid fontanelles close around 6 month after birth.

3-next mastoid fontanelles closes 6 to 18 months after birth.

4- Anterior fontanelle closes between 9 months to 18 months.