3. OBJECTIVES.
Describe the regions of fetal skull
Describe the bones that make up the
vault of the fetal skull
Describe the sutures and fontanelles
Describe the various diameters of the
fetal skull and their significance
4. INTRODUCTION
The fetal head is large in relation to the fetal
body compared with the adult
Adaptation between the skull and the pelvis
is necessary to allow the head to pass
through the pelvis during labour without
complications
5. DEFINITION
Fetal skull is to some extent
compressible and made
mainly of thin pliable flat)
bones forming a vault. This is
anchored to the rigid and
incompressible bones at the
base of the skull.
6.
7.
8. FUNCTION OF FETAL SKULL
Two key functions of the fetal skull are
the protection of the brain, which is subjected
to pressure as it descends through the birth
canal during labour, and an ability to
change shape, adapting to the process of
labour in response to uterine contractions and
the size and shape of the pelvis.
9. vertex
It is a quadrangular area
bounded anterriorly by the
bregma and coronal sutures
behind by the lamda and
lamdoid sutures and laterally by
lines passing through the
parietal eminances.
10.
11. BROW
It is an area bounded on one side by
bregma and coronal sutures and
other side by the root of the nose
and supra orbital ridges of either
side.
12.
13. FACE
It is an area bounded on one side
by root of the nose and supraorbital
ridges and on the other side by the
junction of the floor of the mouth
with neck.
14. SINCIPUT
It is the area lying in the front of the
of the anterior fontanel and
corresponds with the area of brow
and the OCCIPUT is limited to the
occipital bone.
15.
16.
17. SUTURES
IT permits gliding movement
of one suture over the other
during molding of the head.
18.
19. TYPES OF SUTURES IN FETAL
SKULL
SAGITTAL
SUTURES
CORONAL
SUTURES
FRONTAL
SUTURES
LAMBDOID
SUTURES
27. ANTERIOR FONTANEL OR
BREGMA
It formed by joining of four sutures in the
midplane
ANTERIORLY BY FRONTAL SUTURES
POSTERIORLY BY SAGITTAL SUTURES
LATERALLY OR EITHER SIDE BY CORONAL
SUTURES
SHAPE- DIAMOND
DIAMETER: 3 CM
FORMED by membrane & it closed by 18months.
28.
29. POSTERIOR FONTAEL OR
LAMBDA
It formed by joining of three sutures.
ANTERIORLY BY SAGITTAL SUTURES
EITHER SIDE BY LAMBDOID SUTURES
SHAPE- TRIANGULAR
It is membraneous but be come bony at age of 6to
8 weeks.
30.
31. DIAMETETRS OF THE FETAL
SKULL
1. LONGITUDINAL DIAMETERS
2. TRANVERSE DIAMETRS
32. longitudinal DIAMETERS OF THE
SKULL
1. SUBOCCIPITO BREGMATIC
2. Suboccipito-frontal
3. Occipitofrontal
4. Mento-vertical
5. Submentovertical
6. Submentobregmatic
38. 5.SUBMENTOVERTICAL
It extends from junction of the floor of the
mouth and neck to the highest point of the
sagittal suture .
Diameter – 11.5cm
39. 6.SUBMENTOBREGMATIC
It extends from junction of the floor
of the mouth and neck to the center
of the bregma or anterior fontanel.
Diameter – 9.5cm
40. Transverse diameters
The transverse diameters which are concerned
in the mechanism of labour.
1. Biparietal diameter
2. Super-subparietal diameter
3. Bitemporal diameter
4. Bimastoid diameter
43. 2.SUPER-SUBPARIETAL
DIAMETER
It extends from the points placed below one
parietal eminence to the point placed above
the other parietal eminence of the opposite
side.
Diameter -8.5cm
44. 3. BITEMPORAL DIAMETER
It is the distance between the anterior ends of
the coronal sutures.
Diameter -8cm
45. 4. BI – MASTOID DIAMETER
It is the distance between the tips of
the mastoid process.
Diameter – 7.5cm