Short Crisp description of osteology skull cervical vertebrae CVMI skeletal maturity indicators useful both at undergraduate as well as masters level

1. OSTEOLOGY OF SKULL AND
CERVICAL VERTEBRAE
DR.BHUPENDRA BABARIA
Junior resident mds I
Oral health sciences centre ,Pgimer chandigarh
29/08/2019

3. CONTENTS
Introduction
Anatomical position of skull
Calvaria or brain case
Facial skeleton
Joints of skull
Methods of studying skull
Clinical importance
Cervical vertebrae
Clinical implications
3

4. INTRODUCTION
• Brain is the highest seat of intelligence
• Head and neck is the uppermost part of the body
• Head comprises of skull brain , meninges
hypophysis cerebri
special senses , teeth and blood vessels
4
Shakespeare --Uneasy Lies in the head that wears the crown

5. SKULL CONSISTES OF 28 BONES
• The CALVARIA OR BRAIN CASE consists of 14 bones
• The facial skeleton consists of
14 bones
5

6. CALVARIA OR BRAIN CASE
Paired
1. Parietal (2)
2. Temporal (2)
3. Malleus (2)
4. Incus (2)
5. Stapes (2)
Unpaired
1. Frontal (1)
2. Occipital (1)
3. Sphenoid (1)
4. Ethmoid (1)

7. THE FACIAL SKELETON
PAIRED
1. Maxilla (2)
2. Zygomatic (2)
3. Nasal (2)
4. Lacrimal (2)
5. Palatine (2)
6. Inferior nasal
conchae (2)
UNPAIRED
1. Mandible (1)
2. Vomer (1)

8. ANATOMICAL POSITION OF SKULL
• The skull can be placed in proper orientation by
considering any one of the two planes ;
1.Reid's Base Line is a horizontal line obtained by joining
the infraorbital margin to the centre of the external
acoustic meatus , i.e. Auricular point.
2.The Frankfurt Horizontal Plane of orientation is
obtained by joining the infraorbital margin to the upper
margin of the external acoustic meatus
8

9. JOINTS OF THE SKULL
• Sutures
• Few primary cartilaginous
• Three pair of synovial joints
(2 between ear ossicles
1 is the largest TMJ)
9

10. • Plane - Internasal
• Serrate - Coronal
• Denticulate - Lambdoid
• Squamous -
Parietotemporal
• Gomphosis – PDL
• Schindylesis – Ala of Vomer
(wedge groove joint)
10

11. • Vertex – highest point on sagittal suture
• Vault – arched roof for dome of skull
11
TERMINOLOGIES
Parietal tuber (eminence) –
area of maximum convexity of parietal
bone
most common site of fracture of skull

12. • Bregma /anterior fontanelle –
meeting point of coronal and sagittal
(18 to 24 month )
• Lambda / posterior fontanelle –
sagittal and lambdoid suture
(2 to 3 months of age)
12

13. • PARIETAL FORAMEN – one on each side ,
of the parietal bone
2.5 cm to 4 cm in front of
lambda
• OBELION – point on sagittal suture
between two parietal foramen
13

14. METHODS OF STUDYING SKULL
• The skull can be studied as a whole
• Can be studied from outside or externally in different views:
Superior view or NORMA VERTICALIS
Posterior view or NORMA OCCIPITALIS
Anterior view or NORMA FRONTALIS
Lateral view or NORMA LATERALIS
Inferior view or NORMA BASALIS
14

15. • The skull can be studied internally or from inside after
removing the roof of the Calvaria or skull cap
a. Internal surface of cranial vault
b. Internal surface of cranial base ,
natural subdivision into
Anterior – middle – posterior cranial fossae
15

16. • The skull can also be studied as
individual bones
Mandible
Maxilla
Ethmoid
Zygomatic
Sphenoid
Vomer etc
16

17. NORMA VERTICALIS
• How the skull looks from above
• Usually oval in shape
• Wider posteriorly than anteriorly
• Shape maybe more nearly circular
17

18. • Upper part of frontal bone anteriorly
• Uppermost part of occipital bone posteriorly
• Parietal bone on each side
18
BONES SEEN

19. SUTURES SEEN IN NORMA
VERTICALIS
• CORONAL : placed between the frontal bone
and two parietal bones
• SAGGITAL : median plane between two
Parietal bones
• LAMBDOID : lies posteriorly between two
parietal bones runs
downwards and forwards
across the cranial vault
19

20. METOPIC SUTURE
• Only suture which normally closes during infancy
• Present in 3% to 8 % individuals
• Lies in median plane
• Separates 2 halves of frontal bone
• Fuses at 6 yrs of age
• May persist throughout life and may be
mistaken for a fracture
20

21. CLINICAL ANATOMY
• Fontanelles are sites of growth , permitting growth of brain
• Helps to determine age
• If Fontanelles fuse early brain growth is stunted such
children's are less intelligent
• Bones over riding at fontanelle helps to decease size of head during
delivery
21

22. ANTERIOR
FONTANELLE
BULGING
RAISED
INTRACRANIAL
PRESSURE
DEPRESSED
DECREASED
HYDRATION/
DEHYDRATION
22

23. • prolonged elevated intracranial pressure
prolonged papilloedema
cognitive impairment and impaired vision
• Fundoscopy should always be performed during the physical
examination of children with craniosynostosis
23

24. Cappput succdeneum
• soft tissue swelling at any part of skull
due to ruptured capillaries
• Pitting is hallmark feature
• Skull becomes normal within few days
24

25. CRANIOSYNOSTOSIS
25
• Coronal sagittal lambdoid suture are
supposed to close at 22 to 39 months of
age
VIRCHOWS LAW
When premature closure occurs ,
growth of skull is restricted
perpendicularly to the fused suture
and enhanced in a plane parallel to
it
PANSYNOSTOSIS
All sutures closed (in practice 3 or more)

26. ASSOSIATED SYNDROMES
APERT SYNDROME
Acrocephlosyndactyly type 1 , small upper jaw
fusion of fingers and toes
26
CROUZONS SYNDROME
Acrocephlosyndactyly type 2
Bilateral coronal fusion, flat cheek , flat nose ,
exopthalmos, hypertelorism , hypoplastic maxilla

27. PFEIFFER SYNDROME –
Acrocephlosyndactyly type 3
abnormalities of skull
hands and feet wide set, bulging eyes
hypoplastic maxilla, beaked nose
SAETHRE – CHOTZEN SYNDROME
Acrocephlosyndactyly type 5
short broad head, hypertelorism , droopy eyelids
Fingers abnormally short and webbed.
27

28. 28

29. BONES SEEN
29
Posterior parts of parietal bone
above
Upper part of Squamous part of
occipital bone
Mastoid part of temporal bone on
each side

30. SUTURES SEEN IN NORMA OCCIPITALIS
• LAMDOID SUTURE
• OCCIPITOMASTOID SUTURE
• PAREITOMASTOID
• Sagittal suture – posterior part
30

31. OCCIPITAL BONE
• Cranial dermal bone and the main bone of
the occiput (back and lower part of the skull)
• Trapezoidal in shape
• Curved on itself like a shallow dish
• Overlies the occipital lobes of the cerebrum
• At the base of skull in the occipital bone, there
is a large oval opening called the foramen
magnum, which allows the passage of
the spinal cord
31

32. PARIETAL BONE
• The parietal bones are two bones in
the skull which, when joined together at
a fibrous joint, form the sides and roof of
the cranium
• Roughly Quadrilateral
has two surfaces
four borders
four angles
32

33. ANTERIOR VIEW (NORMA
FRONTALIS)
33
The anterior view of the skull
includes the
1. Forehead superiorly
2. Inferiorly the orbits
3. The nasal region
4. The part of the face
between the orbit And the
upper jaw
5. The upper jaw
6. Lower jaw

34. FRONTAL BONE
The forehead consists of the frontal
bone, which also forms the superior
part of the rim of each orbit
Just superior to the rim of the orbit on
each side are the raised
superciliary arches
Rounded curved elevation above
the medial part of each orbit
34

35. Between these arches is a small
depression
(THE GLABELLA)
NASION – median point at root of nose
where internasal suture meets
frontonasal
suture
Clearly visible in the medial part of the
superior rim of each orbit is the supra-
orbital foramen (supra-orbital
notch)
35

36. ORBITAL OPENINGS
• Roughly quadrangular
• FOUR MARGINS
 SUPRA ORBITAL – Frontal bone
 INFRA ORBITAL – Zygomatic laterally and
maxilla medially
 MEDIAL ORBITAL – frontal bone above and
lacrimal crest below
 LATERAL ORBITAL–Frontal process of Zygomatic
and zygomatic process of
frontal bone
36

37. VOMER
• One of the unpaired facial bones of
the skull
• It is located in the midsagittal plane
• Articulates with the Sphenoid
the Ethmoid
left/right Palatine bones
left/right Maxillary bones
• Forms the inferior part of the Nasal septum,
with the superior part formed by
the perpendicular plate of the Ethmoid
bone
37

38. NASAL BONE
2 small oblong bones
varying in size and form in different individuals
placed side by side at the middle and upper
part of the face
by their junction form the bridge of the nose
The nasal articulates with four bones:
Two of the cranium, the Frontal , the Ethmoid
Two of the face, the opposite nasal and
the Maxilla
38

39. CLINICAL ANATOMY
• The nasal bone is most commonly fracture
Because of trauma and projection of nose
• Followed by mandible and parietal eminence
39
The role of multi detector computerized tomography in evaluation of maxillofacial fractures
Article in Egyptian Journal of Radiology and Nuclear Medicine · January 2013

40. MANDIBLE(LOWER JAW)
• Largest and Strongest bone of face
• Develops from the 1st pharyngeal arch
• Horse shoe shaped body - lodges the teeth
• Pair of Rami which provides attachments
to Muscles of Mastication
40

41. BODY OF MANDIBLE
OUTER Surface
• Symphysis menti - Line at which the right/ left
half of the mandible meet
• Mental protuberance – median triangular
projecting in lower part of midline
• Mental foramen – lies below between
two premolars
• Oblique line- sharp continuation of
anterior border of ramus
running downwards & forwards
41

42. INNER SURFACE
1. Mylohyoid line - prominent ridge runs
Obliquely downwards/forwards from 3rd molar to
Median area below genial tubercles
2. Submandibular fossa – lodges
Submandibular gland below Mylohyoid line
3. Sublingual fossa – Sublingual gland above
Mylohyoid line
42

43. 4. Posterior surface of Symphysis menti
is marked by four elevation called
Superior & Inferior Genial Tubercles
5. Mylohyoid groove
Extends on body below posterior end of
Mylohyoid line
43

44. MANDIBULAR FRACTURES
44
• Most condylar fractures are result
of blunt trauma to the anterior mandible
• Forces are transmitted to the condylar
region
• Where posterior movement of mandible
is limited by Glenoid fossa , TMJ capsule ,
Insertion of Lateral pterygoid
• Where forces overcome strength of
condyle fracture occurs

45. THE MAXILLA
• Contributes a large share in the formation of
facial skeleton
• Anterior surface of body of maxilla presents
Nasal notch medially
Anterior nasal spine
Infraorbital foramen 1cm below infraorbital margin
Incisive fossa above incisor teeth
Canine fossa lateral to canine eminence
45

46. PROCESSES OF MAXILLA
• FRONTAL PROCESS – Directed upwards
Articulates anteriorly with
nasal bone
Posteriorly with lacrimal bone
Superiorly with frontal bone
• ZYGOMATIC PROCESS – short stout articulates
with
the zygomatic bone
• ALVEOLAR PROCESS – bears socket for teeth
46

47. SUTURES OF NORMA FRONTALIS
• Frontonasal
• Internasal
• Zygomaticofrontal
• Intermaxillary
• Zygomaticomaxillary
• Nasomaxillary
• Lacrimomaxillary
47

48. STRUCTURES PASSING THROUGH
FORAMINA
FORAMINA VESSELS / NERVES
Supraorbital notch/foramen Supraorbital nerves and vessels
Infraorbital foramen Infraorbital nerves and vessels
Zygomaticofacial foramen Zygomaticofacial ( MAXILLARY NERVE)
Mental foramen Mental nerve and vessels (MANDIBULAR NERVE)
48

49. LATERAL VIEW (NORMA
LATERALIS)
49
• Bones forming the lateral portion
include the frontal, parietal, occipital,
sphenoid, and temporal bones.
• Bones forming the visible part of the
facial skeleton include the nasal,
maxilla, and zygomatic bones.
• The mandible forms the visible part of
the lower jaw.

50. TEMPORAL LINES
50
 Crossing the middle of the parietal
bone in an arched direction are two
curved lines, the superior and inferior
temporal lines
 The former gives attachment to the
temporal fascia
latter indicates the upper limit of the
muscular origin of the temporal muscle

51. SUTURES OF NORMA LATERALIS
• LAMDOID SUTURE
Sutural or wormian bones common
• OCCIPITOMASTOID SUTURE
• PAREITOMASTOID
• coronal SUTURE
51

52. ZYGOMATIC ARCH OR ZYGOMA
• The zygomatic arch, or cheek bone, is formed
by the zygomatic process of the temporal
bone and the temporal process of the
zygomatic bone (the side of the cheekbone)
• The two being united by an oblique suture
(zygomaticotemporal suture)
• The tendon of the temporalis passes medial
to the arch to gain insertion into the coronoid
process of the mandible
52

53. • Above the zygomatic arch is
the TEMPORAL FOSSA which is
filled by TEMPORALIS MUSCLE
• Attached to lower margins is
MASSETER MUSCLE
• Contraction of both can be felt
by clenching the teeth
53

54. STYLOID (TEMPORAL)PROCESS
54
• The styloid process is a process of
bone that extends down from the
TEMPORAL BONE of the human skull
just below the ear
• Serves as an anchor point for several
muscles associated with the TONGUE
and LARYNX

55. REINS OF CHARIOT
• Its Proximal Part (TYMPANOHYAL) is ensheathed by
the tympanic part of the temporal bone
• Its distal part (STYLOHYAL) gives attachment to
the following:
• STYLOHYOID LIGAMENT
• STYLOMANDIBULAR LIGAMENT
• STYLOGLOSSUS (HYPOGLOSSAL NERVE)
• STYLOHYOID (FACIAL NERVE)
• STYLOPHARYNGEUS (GLOSSOPHARYNGEAL NERVE)
55

56. EAGLES SYNDROME (STYLOHYOID
SYNDROME)
• rare condition commonly characterized sudden,
sharp nerve-like pain in the jaw
bone and joint, back of the throat, and base of the
tongue, triggered by swallowing, moving the jaw, or
turning the neck
• elongated or misshapen styloid process (the
slender, pointed piece of bone just below the ear)
and/or calcification of the stylohyoid ligament
56

57. 57

58. CLINICAL ANATOMY
• In road side accidents
anterior division of middle meningeal artery
may be ruptured clot formation between
skull bone and duramater /extradural haemmorhage
• This clot compresses motor area causing paralysis of
opposite side
• Clot must be sucked out earliest by trephination
58

59. NORMA BASALIS
BASE OF THE SKULL
1. Hard palate
2. Sphenoid
3. Vomer
4. Temporal bone with Squamous
And mastoid portions
5. Occipital bone
59

60. HARD PALATE
• Bounded in front and laterally by the alveolar
process
• Has two bones , palatine process of maxilla and
palatine bone
• Two palatine process joined by median palatine
sutures
• And with palatine bone by transverse palatine
suture
• Posterior limit is posterior nasal spine
60

61. FORAMEN OF HARD PALATE
• Behind incisors, INCISIVE
foramen
• Posterolaterally we have
GREATER PALATINE foramen
Transmits descending palatine
vessels and anterior palatine
nerves
• Behind is LESSER PALATINE
foramen
61

62. THE SPHENOID BONE
It has
 Medial and lateral pterygoid process
 Under surface of two great wings
Lateral to the medial plate is SCAPHOID
Fossa , origin of tensor veli palati muscle
Lower extremity has pterygoid hamulus around which the tendon of muscle
turns
62
THE BAT WITH EXTENDED WINGS

63. • The greater wing of sphenoid has three foramen
 Foramen ROTUNDUM
Foramen OVALE
Foramen SPINOSUM

64. FORAMINA CONTENTS
Foramen Rotundum Maxillary nerve
Foramen Ovale Lesser petrosal
Acessory meningeal artery
Mandibular nerve
Emissary vein connecting cavernous sinus with
pterygoid plexus of veins
Foramen Spinosum Middle meningeal artery and vein
Meningeal branch of Mandibular nerve
Foramen Lacerum During life, filled with cartilage
Jugular Foramen CN IX X XI
Inferior petrosal and sigmoid sinus
Meningeal branch of ascending pharyngeal
and occipital arteries
64

65. OCCIPITAL BONE
Through the narrow anterior part
a) Apical ligament of dens
b) Vertical band of cruciate ligament
c) Membrana tectoria
Through the wide posterior part
a) Lower part of medulla oblongata
b) Three meninges
65
FORAMEN MAGNUM

66. • Through the SUBARACHNOID space
a) Spinal accesory nerves
b) Vertebral arteries
c) Sympathethic plexus around the
vertebral arteries
d) Posterior spinal arteries
e) Anterior spinal artery
66

67. CERVICAL VERTEBRAES
67

68. INTRODUCTION
There are 7 cervical vertebrae's which form the bony network of the neck
THREE are atypical
THREE TO SIX are typical (4)
Characterised by the presence of
FORAMINA TRANSVERSARIA
68

69. CHARACTERISTICS OF TYPICAL
VERTEBRAE
• Small bodies
• Bifid spinous process
• Transverse process that contain a
foramen (FORAMEN TRANSVERSARIUM)
69

70. ATYPICAL VERTBRAES
FIRST CERVICAL VERTEBRAE
70

71. IDENTIFICATIONS
• Ring shaped
• Neither body nor spine
• Short anterior arch
• Long posterior arch
• Right/left lateral masses
• Transverse process
71

72. • ANTERIOR ARCH Is marked by
median anterior tubercle on anterior aspect
• Posterior surface bears
Oval facet which articulates with dens
• POSTERIOR ARCH Forms 2/5th of ring
Much longer than anterior arch
• Posterior surface is marked by
Median posterior tubercule
72

73. SECOND CERVICAL VERTEBRAE
73
•Called AXIS
•Characterized by presence of dens or
odontoid process
•Usually believed to represent
Centrum or body of atlas which has
fused with the Centrum of axis

74. SEVENTH CERVICAL VERTEBRAE
• Vertebrae prominens
• Long spinous process at tip
Can be felt through skin
At the lower end of nuchal furrow
• Spine thick long nearly horizontal
• Not bifid but ends in tubercle
74

75. CLINICAL ANATOMY
• During judicial hanging
The odontoid process usually
breaks to hit
upon the vital centers in the
medulla oblongata
75

76. • HANGMANS FRACTURE occurs due to
fracture of pedicle of axis vertebrae
• As vertebral canal gets enlarged spinal
cord does not get pressed
76

77. • Prolapse of intervertebral discs occurs at
the junction of different curvatures
• Most common site Is lower cervical &
upper lumbar vertebral regions
• Pharyngeal ad retropharyngeal
inflammation may cause decalcification of
atlas
• This may lead to loosening of attachments
of transverse ligament which may
eventually yield, causing SUDDEN INFANT
DEATH SYNDROME
77

78. OCCIPITALISATION/ ASSIMILATION
• The Atlas May Fuse With The Occipital Bone
This Is Called OCCIPITALISATION Of Atlas
• May Compress The Spinal Cord Which
Requires Surgical Decompression
78

79. SKELETAL MATURITY EVALUATION
STAGE ONE INITIATION
• 80 to 100% growth expected
• lower border c2 c3 c4 flat
• Wedge shaped vertebrae
• Superior border tapered from
posterior to anterior
STAGE TWO acceleration
• 65 to85% growth expected
• Nearly rectangular
• Concavities starts developing at
inferior border
79
HASSEL AND FARMAN

80. STAGE THREE transition
• 25 to 65% growth expected
• Rectangular in shape
• Distinct concavities seen in inferior borders of c2 c3
• A concavity starts beginning at c4
STAGE FOUR deceleration
• 10 to 25% growth expected
• Distinct concavities seen in inferior borders of c2 c3 c4
• Square shaped
80

81. • STAGE FIVE maturation
• 5 to 10%
• Nearly square
• Accentuated concavities seen in c2 c3 c4
• STAGE SIX completion
• little of no growth
• Square in shape
• Deep concavities in c2 c3 c4
81

82. CONCLUSION
• Osteology of head and cervical vertebrae helps us to determine growth of
individual
• Age determination and serves as reliable indicators of skeletal maturity
• Bone morphology
• Types and patterns of fractures
82

83. REFERENCES
• BDC Human Anatomy - Head, Neck & Brain (Volume 3)
• Gray's Anatomy for Students 3rd Ed
• Anand's Human Anatomy For Dental Students - Mahindra Kumar Anand - 3rd Edition
(2012)
• Lippincott’s Concise Illustrated Anatomy - Head & Neck - Volume 3 - Ben Pansky, Thomas
R. Gest – 1st Edition (2014)
• Textbook Of Anatomy Head, Neck And Brain - Volume III - Vishram Singh - 2nd Edition
(2014)
83

84. THANK YOU
84