3. Introduction
• At birth, the calvaria is large in proportion to
other skeletal parts, reflecting cerebral
maturation.
• The facial region is relatively small and
constitutes only about one-eighth of the
neonatal skull, whereas it constitutes about
half of the adult skull.
6. Fetal Skull
• Skull bones encase
and protect the
brain
• Major 3 Parts
Vault
Face
Base
7. Bones of the Vault
2 Frontal Bones
2 Parietal Bones
1 Occipital Bones
2 Temporal Bones
8. Vault
• Large, dome shaped part above an imaginary
line drawn between the orbital ridges and
nape of the neck
• Base
Base comprises bones that firmly united to
protect the vital centers in the medula
oblangata
Face
Comprises of 14 bones that are firmly united and are
non-compressible
9. 2 Frontal Bones
• Form the forehead or
Sinciput
• The ossification center
of each bone is frontal
eminence
• Fuse into single bone by
8 years of age.
10. 2-Parietal Bones
• Lie on either side
and occupy most
of the skull
• Parietal
eminence(Ossificat
ion Centre)
13. Fontaneles
• The fibrous membrane that
forms the calvaria remains
unossified at the six angles of
the parietal bones, producing
six fontanelles:
• Two single midline (anterior
and posterior) and
• Two lateral pairs
(sphenoidal/anterolateral and
mastoid/posterolateral).
15. Anterior Fontanelle
• Largest and Rhomboid
• 4 cm AP
• 2.5 Transverse
• Formed between Sagittal,
Transverse and Frontal
Suture
• Closes at 12-18 months.
16. Clinical
• Palpation of fontanelle
is useful clinically.
• Sunken fontanelle
indicates dehydration
• Tense or bulging
anterior fontanelle
indicates
raised intracranial
pressure. E.g
Meningitis ,
Hydrocephalus
18. Anteriolateral Fontanelle
• Sphenoidal Fontanelle
• Lies at sphenoidal angle
of Parietal Bone between
the sphenoid, parietal,
temporal, and frontal
bones
• Fuses at 6 Months
19. Posteriolateral Fontanelle
• Mastoid Fontanelle
• Bilateral soft
membranous gaps at the
junction of
the parietomastoid, occi
pitomastoid,
and lambdoid sutures
• Fuse at 6-18 months
• Persists as Asterion
21. Metopic Suture
• Also known as median
frontal suture
• Vertical fibrous joint that
divides the two halves of the
frontal bone runs cross the
frontal bone from
the nasion to the bregma.
• Fusion 3-9 months
23. Coronal Suture
• Cranial suture formed
between the two parietal
bones and the frontal
bone.
• Junction of the Anterior
Fontanelle
• Fuses at 24 years of age
24. Oxycephaly
• Craniosynostosis in which
top of the skull is pointed or
conical due to premature
closure of the coronal
suture.
• Most severe form of
craniosynostosis.
• Characterised by
• 8th cranial nerve lesion
• Optic nerve compression
• Mental deficiency
25. Plagiocephaly
• Flat Head Syndrome
• Asymmetric premature
closure of the coronal
suture/lambdoid suture.
• Widespread form is
characterized by a flat
spot on the back or one
side of the head caused
by remaining in a supine
position for prolonged
periods
26. Sagittal Suture
• Midline articulation that
joins the two parietal
bones
• Normal fusion at 22
years.
27. Scaphocephaly
• Most common form
of craniosynostosis
• Premature closure of
the sagittal suture
• Results in an impediment
to the lateral growth of
the skull while
anteroposterior growth
continues, producing a
narrow and elongated
skull.
28. Squamosal Sutures
• Arches backward from
the pterion and connects
the temporal squama
with the lower border of
the parietal bone
• May not completely
close until 60 years of
age.
29. Lambdoid Suture
• Junction between the
superior border of
the occipital bone and the
posterior borders of the
right and left parietal bones
• Fuses at approximately 26
years
30. Sphenofrontal Suture
• Between Frontal and Sphenoid Bone
• Anteriorly suture appears on the roof of the
bony orbit.
• Laterally as meeting point of inferior posterior
edges of frontal bone and anterior, superior
edge of the greater wing of the sphenoid bone
• Fuses at 15 years of age.
33. • 1) At what age the anterior fontanelle fuse?
a) 12-18 Months
b) 18-36 Months
c) 6-12 Months
d) 3-6 Months
Ans : A
34. • 2) A mother bought her 1 month old baby in the OPD
with the complaint of fever. The physician did the
physical examination and found raised intracranial
pressure. Which of the following fontanelles suggest
the same after proper palpation ?
a) Anterior
b) Posterior
c) Sphenoidal
d) Mastoid
Ans : A
35. 3) Trigonocephaly results from which of the
following Synostosis?
a) Lambdoid
b) Sagital
c) Coronal
d) Mitopic
Ans: D
