fetal skull introduction of fetal skull and detail information of fetal diameter of skull

1. FETAL SKULL
PRESENTD BY,
MS. MILAN SAWANT,

2. INTRODUCTION
• The fetal head is large in relation to the
fetal body compared with adult.
• Adaptation between the skull and the
pelvis is necessary to allow the head to
pass through the pelvis during labour
without complication.

4. FETALSKULL
• The skull bones encases and protect the
brain.
• Fetal skull is compressible, and made mainly
of thin pliable tabular(flat) bones forming the
vault.
The fetal skull has three major parts :
• Vault of the cranium (Roof)
• Face
• Base

8. VERTEX
• It is a quadrangular area bounded anteriorly
by the bregma and coronal suture behind by
the lambda and lambdoidal sutures and
laterally by lines passing through the parietal
eminences.
BROW
• It is an area bounded on one side by the
anterior fontanelle and coronal sutures and
on the other side by the root of the nose and
supra-orbital ridges of either side

9. FACE
• It is the area bounded by the root of the
nose and supra- orbital ridges and on the
other, by the junction of the floor of the
mouth with neck.
SINCIPUT
• It is the area lying in front of the anterior
fontanelle and corresponds to the area of
brow. OCCIPUT It is the area limited to the
occipital bone.

10. SUTURES
Flat bones of the vault are
united together by the non- osssified
membranes attached to the margins of the
bones. These are called sutures.
• THE SAGGITAL SUTURE: Lies b/w two
parietal bones.
• THE CORONAL SUTURES : Run b/w
parietal and frontal bones on either sides.
• THE FRONTAL SUTURE : Lies b/w two
frontal bones.
• THE LAMBDOIDAL SUTURES : Separate
the occiput bone and two parietal bones.

11. IMPORTANCE
• It permits gliding movement of one bone
over the other during moulding of the
head.
• Digital palpations of sagittal suture during
internal examination in labour gives an
idea of the manner of engagement of the
head, degree of internal rotation of the
head and degree of moulding of the head.

12. fontanelle
• Wide gap in the suture line is called fontanelle
ANTERIOR FONTANELLE:
Formed by joining four sutures in midplane.
- Anteriorly frontal bone.
- Posteriorly saggital.
- On either side coronal suture.
- Diamond like shape.
- Floor is made by a membrane.
- Ossified at 18months after birth

13. IMPORTANCE
• Its palpation through internal examination denotes the
degree of flexion of the head.
• It facilitates moulding of the head.
• As it remains membranous long after birth, it helps in
accommodating the marked brain growth, the brain
becoming almost double its size during first year of life.
• Palpation of the floor reflects intracranial status-
depressed in dehydration, elevated in raised intracranial
tension.
• Collection of blood and exchange transfusion, on rare
occasion, can be performed through it via the superior
longitudinal sinus.
• Cerebrospinal fluid can be drawn, although rare, through
the lateral angle of the anterior fontanelle from the lateral
ventricle.

14. POSTERIOR FONTANELLE:
Formed by junction of three sutures.
Saggital suture anteriorly.
• Lambdoidal suture on either side.
• Triangular in shape.
• Measure about 1.2 x1.2cm.
• Its floor is membranous but become bony
at 3months

15. SAGGITAL FONTANELLE:-
• It is inconsistent in its presence.
• It is situated on the saggital suture at the
junction of anterior to two-third and
posterior one-third.
• It has got no clinical importance.

16. LANDMARKS
• Occiput- is the occipital bone/external occipital
protuberance.
• Sinciput- is the forehead region of fetal head.
• Parietal eminences- are the eminences of
parietal on either side.
• Mentum- it is the chin.
• Vertical point- it is the center of saggital suture.

17. CONT…
• Frontal point- is the root of nose.
• Sub occiput- is the junction fetal neck and
occiput.
• Sub mentum- it is the junction between
neck and chin.
• Bi parietal- is the transverse distance
between two parietal eminences.
• Bi temporal- is the distance between two
lower end of coronal suture.

18. DIAMETER OF SKULL
• TRANSVERSE DIAMETER:-
- Bi parietal Diameter- Measure about 9.5cm. It
extends between two parietal eminences.
• Bi-temporal diameter :-
- Measure about 8cm.
- It is the distance between anterio-inferior ends
of the coronal suture.

19. • LONGITUIDNAL DIAMETER :
- Sub-occipitobregmatic- 9.5cm.
The diameter from below the occipital
protuberance to the center of the anterior
fontanelle.
• Sub-occipitofrontal- 10cm.
The diameter from below the occipital
protuberance to the center of the frontal suture.
• Occipitofrontal-11.5cm.
The diameter from the occipital protuberance to
the glabella.

20. • Mentovertical-13.5cm.
The diameter from the point of the chin to the
highest point on the vertex, slightly nearer to
the posterior than to the anterior fontanelle.
• Submentovertical-11.5cm.
The diameter from the point where the chin joins
the neck to the highest point where the chin
joins the neck to the highest point on the vertex.
• Submentobregmatic-9.5cm.
The diameter from the point where the chin joins
the neck to the center of bregma.

24. • UMMERIZATION Today we discussed about the
Fetal skull:- • Definition • Parts of the fetal skull •
Sutures • Fontanelle • Region and landmarks of
the fetal skull. • Diameters of Fetal skull
• 19. BIBLIOGRAPHY Shirish S Sheth,“Essential
of Obstetrics”, 1st Edition, Jaypee Brothers
Medical Publishers, New Delhi,2004, page no.:
102 - 104. Diane M, “Myles textbook for
Midwives”, 14th edition, Elsevier Publisher,
London, 2008, page no: 157-160 Dutta D.C,
“Textbook of obstetrics” 7thedition Published By
New Central Book Agency, page 86-89