This document discusses the growth and development of the cranial vault from prenatal development through postnatal growth. It begins with the bones present at birth (45 elements) consolidating into 22 bones in adults. Prenatal development involves the condrification and ossification of cartilage anlagen into bones. Several sutures and fontanelles are present initially which fuse at defined timepoints as the brain expands outward, pushing the bones and reshaping the cranial fossae. The spheno-occipital synchondrosis acts as the primary growth center, with expansion also aided by other synchondroses. Postnatally, remodeling continues to accommodate neural and vascular structures through the childhood years.
10. Time of closure
Fontenallae
-Anterior
-2nd year
-posterior
-2 mts
-Ant lateral
-3mts
-Post lateral
-end of 1 yr
-Medial frontal suture
-6 to 8 yrs
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11. Post-natal growth of cranial
vault
Growth
of brain
Cephalocaudal
Theories
gradient of growth
of growth
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26. Anterior cranial fossa
Orbital
part of frontal bone
Cribriform
Anterior
plate of ethmoid bone
part of body of sphenoid &
lesser wing of sphenoid
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29. Middle cranial fossa
Deeper than ant cranial fossa
Shaped like a butterfly
In
front bounded by post part of
lesser wing of sphenoid & body of
sphenoid
Behind
by sup border of temporal
bones & dorsum sellae of sphenoid
bone
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32. Pre-natal growth
Cranium divided into 2 parts
•Neurocranium-protects, supports;
brain, sense organs
•Viscerocranium-elementary, resp
track, face, max & mandible
Basicranium - both
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45. Chondrocranial ossification
• 110 ossi centers – embryonic skull
• 45 bones – neonatal skull
• 22 bones – young adult
• Unossified remnents – ala,nasal sepum,
speno-occi&speno-petrous jn,apex
of petrous bone,btwn separate
parts of occ bone
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46. Occipital bone
7 ossi centers - 2
intramembranous
5 endochondral
Sq portion above sup
nuchal line –ossify
from pair of i.m ossi centers
8th i.u week
Infranuchally – pair of
endochondral
centers 10th i.u week
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47. Occipital bone
Single median
endochondral ossi
center at 11th week
ant to fora magnum&
ant 3rd occi condyl
pair of endochondral
ossi centers at 12th
week from
exocci bone lat to
magnum including
2/3rd occi condyl
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52. Ethmoid bone
Ossifies from 3 centers
Single median center in mesethmoid
cartilage – forms ppd plate & crista
galli just before birth
A pair appear in nasal capsular carti
4th i.u month
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59. Bony elevations b/w fossae, divide fossa
into various compartments
Middle & post fossae by petrous
elevation
Olfactory fossae by crista galli
Rt & left mid cranial fossae by midline
sphenoidal elevation
Rt & left ant & post cranial fossae by
longi midline bony ridge
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60. Post-natal growth
Fossa expands outward by resorption,
Partitions between them enlarge
inward by deposition
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61. Post-natal growth
Remodelling provides stability for
nerves & vessel passage way
Foramina undergo remodelling &
drift to maintain position of cranial
nerves & major blood vessels
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62. Synchondrosis
Regarded as growth center &
pacemaker of cranial base
Midline part of cranial base
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63. Synchondrosis at the base
Spheno-ethmoidal synchondrosis
Intersphenoidal synchondrosis
Spheno-occipital synchondrosis
Intraoccipital synchondrosis
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64. Spheno-occipital synchondrosis
Principle growth cartilage of base
Present till brain & base conti to
grow & expand
Its growth ceases at 12 to 15, at
20 sphenoid&occi segments fuse
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65. Structure of synchondrosis
Zones of cartilage Familial reserve zone
Cell division zone
Hyper tropic zone
Calcified zone
Two major directions
Of linear growth
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