This document discusses the fetal skull, including its parts, sutures, fontanelles, regions, landmarks, and diameters. The fetal skull has three main parts - the vault of cranium, face, and base. It is made up of several flat bones joined by sutures, which allow movement during birth. The skull has fontanelles that are membranous areas where sutures meet. The skull's regions include the occiput, vertex, sinciput, and face. Its diameters and landmarks help assess proper adaptation for birth. Understanding the fetal skull is important for evaluating labor progression and detecting any complications.

1. FOETAL SKULL
BY : MR. BASAVARAJ
4TH YEAR BSC NURSING
ESIC COLLEGE OF NURSING
KALBURGI

2. LEARNING OBJECTIVES
• INTRODUCTION
• PARTS OF FOETAL SKULL
• SKULL SUTURES
• FONTANELLES
• REGIONS
• LAND MARKS OF FOETAL SKULL AND
• DIAMETERS OF FOETAL SKULL

3. INTRODUCTION
AS CONCERNED WITH THE LABOUR, FOETAL SKULL IS AN IMPORTANT
ASPECT TO STUDY, BECAUSE OF ITS ADAPTATION NECESSARY TO ALLOW
THE HEAD TO PASS THROUGH THE PELVIS DURING LABOUR WITHOUT ANY
OBSTRUCTION OR COMPLICATION. ANY ABNORMAL SIZE OR THE
DIAMETERS OR IF THERE IS NO PROPER ADAPTATION OF THE FOETAL SKULL
WITH MATERNAL PELVIS MAY LEADS TO COMPLICATIONS DURING LABOUR
LIKE OBSTRUCTED LABOUR. ADAPTATION OF FOETAL SKULL TAKE PLACE
WITH VARIOUS MECHANISM AND THEY ARE,
• ENGAGEMENT
• PRESENTATION
• MOULDING
• ROTATION

4. PARTS OF FOETAL SKULL
THE FOETAL SKULL HAS 3 MAJOR PARTS,
1. THE VAULT OF CRANIUM (ROOF)
2. THE FACE AND
3. THE BASE (CRANIUM)

5. CONTI……
• THE VAULT OF CRANIUM (ROOF):
THE SKULL VAULT HAS GOT 7 FLAT BONES CONNECTED
TOGETHER WITH SUTURES, THE BONES OF FETAL SKULL ARE,
• FRONTAL BONES (TWO IN NUMBER)
• PARIETAL BONES (TWO IN NUMBER)
• TEMPORAL BONES (TWO IN NUMBER) AND
• OCCIPITAL BONE (ONE)

6. CONTI…
• FACE
FACE IS COMPOSED OF 14 SMALL BONES THAT
ARE ALSO FIRMLY UNITED AND THOSE ARE NO-
COMPRESSIBLE.
• BASE OF THE SKULL
THE BASE COMPRISES OF BONES THAT ARE
FIRMLY UNITED TOGETHER TO PROTECT THE VITAL
CENTERS IN MEDULLA OBLONGATA.

7. SUTURES OF THE FETAL SKULL
SUTURES ARE THE IMMOVABLE JOINTS OF THE SKULL WHERE BONES
ARE CONNECTED TOGETHER WITH FIBROUS TISSUE. THE SUTURES OF FETAL
SKULL ARE,
• FRONTAL SUTURE : BETWEEN TWO FRONTAL BONES.
• CORONAL SUTURE : BETWEEN TWO FRONTAL AND PARIETAL
BONES.
• SAGITTAL SUTURE : BETWEEN TWO PARIETAL BONES.
• LAMBDOIDAL SUTURE : BETWEEN TWO PARIETAL AND OCCIPITAL BONE.
• SQUAMOUS SUTURE : BETWEEN TEMPORAL AND PARIETAL
BONES.
IMPORTANCE: (1) IT PERMITS GLIDING MOVEMENT OF ONE BONE OVER THE OTHER DURING MOLDING OF THE
HEAD, A PHENOMENON OF SIGNIFICANCE WHILE THE HEAD PASSES THROUGH THE PELVIS DURING LABOR. (2)
DIGITAL PALPATION OF SAGITTAL SUTURE DURING INTERNAL EXAMINATION IN LABOR GIVES AN IDEA OF THE
MANNER OF ENGAGEMENT OF THE HEAD, DEGREE OF INTERNAL ROTATION OF THE HEAD AND DEGREE OF
MOLDING OF THE HEAD.

8. CONTI…..

9. FONTANELLE
FONTANELLE ARE MEMBRANOUS PARTS WHERE TWO OR MORE
SUTURES MEETS AND THE BONES HERE ARE NON-OSSIFIED.
BASICALLY FETAL SKULL HAS GOT 6 FONTANELLE AMONG TWO HAVE
OBSTETRIC SIGNIFICANCE, AND THEY ARE
• ANTERIOR FONTANELLE
• POSTERIOR FONTANELLE.

10. CONTI….
ANTERIOR FONTANELLE:
THIS FONTANELLE IS ALSO CALLED AS BREGMA, IT IS SITUATED
AT THE JUNCTION OF FRONTAL, CORONAL AND SAGITTAL SUTURES.
IT CLOSES AT 18 MONTH (1 ½ YEAR) AND IT IS DIAMOND IN SHAPE.
IMPORTANCE:
• ITS PALPATION THROUGH INTERNAL EXAMINATION DENOTES THE DEGREE OF FLEXION OF THE
HEAD.
• IT FACILITATES MOLDING 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 THE FIRST YEAR OF
LIFE.

11. CONTINUED…..
• 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 RARELY, THROUGH THE ANGLE OF
THE ANTERIOR FONTANEL FROM THE LATERAL VENTRICLES.
POSTERIOR FONTANELLE:
IT IS ALSO CALLED AS LAMBDOID FONTANELLE, IT IS
SITUATED AT THE JUNCTION OF SAGITTAL SUTURE ANTERIORLY
AND LAMBDOID SUTURE ON EIGHTER SIDES. THIS FONTANELLE
CLOSES AT 8TH WEEK (1 ½ MONTH) AND IT IS TRIANGULAR IN
SHAPE.

12. REGIONS OF FOETAL SKULL
FOETAL SKULL IS DIVIDED IN TO FOUR REGIONS,
1. OCCIPUT REGION
2. VERTEX REGION
3. SINCIPUT REGION OR BROW AND
4. FACE

13. CONTI….
• OCCIPUT REGION: LIES BETWEEN THE FORAMEN MAGNUM AND
POSTERIOR FONTANELLE, IT INCLUDES SUB-OCCIPITAL REGION (THE
PART BELOW THE OCCIPITAL PROTUBERANCE).
• VERTEX REGION: BOUNDED BY THE TWO PARIETAL BONES, PARIETAL
EMINENCES BY SIDE, ANTERIOR FONTANELLE AND CORONAL
SUTURES IN THE FRONT. AND POSTERIOR FONTANELLE AND
LAMBDOIDAL SUTURE BEHIND.
• SINCIPUT REGION: EXTENDED FROM THE ANTERIOR FONTANELLE AND
THE CORONAL SUTURES TO THE ORBITAL RIDGES IN THE FRONT.
• FACE: AREA BOUNDED BY THE ORBITAL RIDGES OF EYE TO THE NOSE
AND MENTUM.

14. LANDMARKS OF FETAL SKULL
1. CHIN OR MENTUM
2. SUB-MENTUM : BELOW THE MENTUM
3. SINCIPUT : IT IS THE AREA BETWEEN THE ORBITAL RIDGES
AND CORONAL SUTURE.
4. PARIETAL EMINENCES:- ARE THE EMINENCE OF THE PARIETAL
BONE ON EITHER SIDES.
5. GLABELLA : AT THE ROOT OF THE NOSE.
6. VERTEX : THE AREA BETWEEN CORONAL AND PARIETAL
EMINENCES.
7. OCCIPUT :
8. SUB-OCCIPITAL REGION : AREA BELOW THE OCCIPITAL REGION.

15. DIAMETERS OF FETAL SKULL
Sl/n Diameters Description of measurement Length
Transvers diameters
01 Bitemporal It is the distance between the
anteroinferior ends of the coronal suture.
8.2 cm
02 Biparietal Between two Parietal Eminences. 9.5 cm
Antero-posterior(AP) or Longitudinal diameters
01 Suboccipitobregmatic Measured from sub-occiput to Bregma. 9.5 cm
02 Suboccipito-frontal Measured from Sub-occiput to centre of
frontal suture.
10 cm
03 Occiputoglabellar /
Occipitofrontal
Measured from occipital protuberance
to the Glabella (root of the nose).
11.5 cm
04 Submentobregmatic Measured from submental to Bregma 9.5 cm
05 Submento-verticle Measured from submental to vertex 11.5 cm
06 Mentoverticle Measured from mentum to vertex 13.5 cm

16. REFERENCES
• D.C DUTTA, TEXTBOOK OF OBSTETRICS, PAGE NO: 87-91, 8TH EDITION, JAYPEE
BROTHERS MEDICAL PUBLISHERS (P) LTD.
• ANNAMMA JACOB MSC(N), MIDWIFERY CASEBOOK FOR BSC NURSING STUDENTS,
PAGE NO: 5-7, 7TH EDITION, JAYPEE BROTHERS MEDICAL PUBLISHERS (P) LTD.