Fontanelle, paediatrics

Fontanelle

Fontanelle are soft membranous part of fetal skull, which are formed by merging of two or more than two sutures. According to the importance of labour two fontanelle of fetal skull are as follows

1. Anterior fontanelle
2. Posterior fontanelle

1. Anterior Fontanelle

Anterior fontanelle is a diamond shape fontanelle, which is made up by merging of frontal suture. Both coronal suture & saggital suture. Anterior fontanelle is commonly known as bregma & it is ossified at the age of 18th month.

2. Posterior Fontanelle

Posterior fontanelle is a triangular fontanelle, which is made up by saggital suture & both lambdoid suture. Posterior fontanelle is commonly known as 'lambda' & it is ossified at the age of 1 1/2 month.

Diameter Of Fetal Skull

According to the process of labour diameter of fetal skull can be divided into two categories

(A). Anterior posterior diameter
(B). Transverse diameter

(A). Anterior posterior diameter

These are the diameter of fetal skull in which fetal skull is engaged in anterior posterior angle in maternal pelvis. These anterior posterior diameter of fetal skull are as follows

1. Sub occipito bragmatic (SOB)
9.5 cm from lowest point of occipit to the bregma.

2. Sub occipito frontal (SOF)
10 cm from lowest point of occipital bone to the mid point of frontal bone.

3. Occipital frontal (OF)
11 cm from eminence of occipit to mid point of frontal bone.

4. Mentoverticle (MV)
14 cm from tip of chin to vertex of skull.

5. Submentoverticle (SMV)
11.5 cm from tip (base) of chin to vertex of skull.

6. Submento bragmatic (SMB)
9.5 cm from base of chin to bregma.

7. Transverse diameter of fetal skull
Transverse diameter of fetal skull are as follows

(a). Bi parietal diameter
9.5 cm, in between both parietal eminence.

(b). Super sub parietal diameter
8.5 cm above parietal eminence & other point below the parietal eminence.

(c). Bi temporal diameter
8 cm in between both temporal bones.

(d). Bi mastoiditis diameter
7.5 cm in between both mastoid process.