Page 29 - 2023 Elctronic Book (3) Normal Labor_Neat

Fontanelles:

Areas where sutures meet. They are six in number.
Four fontanelles lie at the anterior & posterior end of the temporal sutures on each

side no obstetric importance.
Anterior Fontanelle or Bregma:
▪ It is large, lozenge shaped.

▪ Formed by the meeting of four bones, two frontal and two parietal bones.
▪ Has a soft membranous floor.
▪ Becomes obliterated 1.5 years after birth.

Posterior Fontanelle:
▪ Small, triangular shaped.
▪ Formed by the meeting of three bones, two parietal bones and the occipital

bone.
▪ Has a bony floor.
▪ It is obliterated at full term.
▪ Membranous in the preterm baby.

 NB: The anterior temporal fontanelles are at the junction of the temporal and
coronal sutures. The posterior temporal fontanelles are at the junction of the

temporal and lambdoidal sutures.
Anterior &Posterior Fontanelles are important to diagnose:
1-Vertex presentation
2-Position of occiput

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