• Introduction, General embryology○ Fertilization ○ Formation of germ layers ○ Development of face – •Pharyngeal arches, pouch & clefts ○ Development of nose. development of maxilla & mandible, development of eyes,development of lips & checks Development of head • Development of skull • Development of face.....

1. 1

2. DEVELOPMENT OF FACE
Dr. DISHIKA BHAGWANI
PG 1
DEPARTMENT OF
PEDODONTICS &
PREVENTIVE DENTISTRY
2

3. CONTENT
PART 1:-
• Fertilization, cleavage
• Formation of morula, blastocyst
• Formation of germ layers
• Formation of procordal plate , primitive streak & intraembryonic mesoderm
• Formation of notochord
• Sub-division of intraembryonic mesoderm
• Embryonic folding
• Stomodeum
• Formation of pharyngeal arches, pouches & clefts
• Derivatives of pharyngeal arches, pouches & clefts
3

4.  PART 2:- DEVELOPMENT OF -
 MAXILLA
 NOSE
 LIP
 CHEEK
 PALATE
 TONGUE
 MANDIBLE
 TOOTH
 EYE
 EAR
 CONGENITAL ABNORMALITIES
 REFERENCES
4

5. INTRODUCTION
 The face and neck development of the
human embryo refers to
the development of the structures from the
third to eighth week that give rise to the
future head and neck.
 This is due to germ layers:-
 Etcoderm – outer layer
 Mesoderm – middle layer
 Endoderm – inner most layer
5

6. FERTILIZATION
 Fertilization of the ovum occurs in
the ampulla of the uterine tube.
 The nucleus of the ovum- Female
Pronucleus. The head of the
spermatozoon -Male Pronucleus –
zygote
 The 23 chromosomes of both the
pronuclei get mixed up- form 46
chromosomes. These undergo
typical mitotic divisions to form an
embryo having two cells (2nd Day)
6

7. 7

8. FORMATION OF MORULA & BLASTOCYST
 Pre Implantation period -The period of one week from
fertilization to implantation of fertilized egg
 The fertilized ovum undergoes cleavage as it moves towards the
uterine cavity
 By 3rd day when zygote reaches uterus, it is a many celled mass
called as MORULA which is 16 cell stage.
8

9.  On cross section, morula consists of inner cell
mass surrounded by an outer cell layer.
 Outer cell layer-later forms Trophoblast-
provide nutrition to the growing embryo
 Inner cell layer, is embryo proper-
Embryoblast
9

10.  4th – 5th day, 32 – 64 cells
 In the uterine cavity, some fluid passes into the
morula thus separating the inner cell mass
from trophoblast moving it to one side
 Inner cell mass attaches to inner side of the
trophoblast on one side only.
 Hence, Morula Blastocyst
 Cavity of the blastocyst is called as
Blastocoel.
 Blastocele seperates the cell into 2 parts –
Trophoblast (outer cell layer)
Embryoblast (inner cell mass)
10

11. 11

12. IMPLANTATION : 6TH DAY
 Trophoblast attaches to the sticky endometrial
surface on the posterior wall of the body of
uterus
 Surface of cells of trophoblast produces
enzymes that digest the uterine endometrial cells
which allows a deeper penetration of the cell
mass
12

13. FORMATION OF GERM
LAYERS
13

14.  Some cells of inner cell mass become
flattened & come to line free surface-
hypoblast/endoderm
 Remaining, become columnar-
epiblast/ectoderm
 Bilaminar germ disc.
 Space between epiblast and trophoblast-
Amniotic Cavity filled with amniotic fluid.
 Roof - amniogenic cells, floor - epiblast
 Flattened cells from hypoblast spread inside
blastocystic cavity, forming Heuser’s
Membrane
 Hence, the cavity now is lined by cells from
all sides- Primary Yolk Sac
14

15.  The cells of trophoblast give rise to mass of cells- Extra Embryonic Mesoderm (Primary Mesoderm)-
does not give rise to any tissues of the embryo.
 Small cavities appear here and these ultimately join together to form a large cavity, the Extra Embryonic
Coelom (Chorionic Cavity).
 With the formation of extra embryonic coelom, the extra embryonic mesoderm is split –
Parietal/somatopleuric extraembryonic mesoderm:
Lines inside of trophoblast and outside of amniotic cavity
Visceral/splanchnopleuric extraembryonic mesoderm:
Lines outside the yolk sac
15

16. FORMATION OF PROCORDAL PLATE ,
PRIMITIVE STREAK &
INTRAEMBRYONIC MESODERM
 Day 13 – Prochordal plate – one circular end of disc
– cubical cells of endoderm become columnar
 Now, central axis is determined enabling us to
distinguish the future head and tail ends.
 Few columnar cells of epiblast at tail end begin to
proliferate to form an elevation that bulges into the
amniotic cavity- PRIMITIVE STREAK (day 15),
appears on dorsal aspect of ectoderm of embryonic
disc
16

17.  Cells that proliferate in primitive streak pass sideways
between epiblast and hypoblast forming the Intra
embryonic mesoderm (Secondary Mesoderm)- 16th
day of IUL
 By the end of third week, mesoderm migrates in lateral
direction between ectoderm & endoderm, except at
region of prochordal plate & area caudal to primitive
streak, where ectoderm and endoderm remain in
contact.
 These regions remain thin & form buccopharyngeal
membrane at prochordal plate & cloacal membrane
caudal to primitive streak
17

18. 18

19. FORMATION OF
NOTOCHORD
 By day 16, a primitive knot of cells,
the Henson’s node, appears at the
cephalic end of the primitive streak
 This knot gives rise to cells that forms
the notochordal process
19

20. FORMATION OF NOTOCHORD
 Between cranial end of Primitive streak &
Caudal end of Prochordal plate
 Cranial end of primitive streak thickens
Primitive Knot/primitiv node/Henson’s
node
 Blastopore appears which is a depression in
the knot
 Cells in the primitive knot multiply, pass along
the caudal end of prochordal plate, between
endoderm and ectoderm forming solid cord
known as Notochordal process/head process
 Cells undergo rearrangement forming a solid
rod called as NOTOCHORD
20

21. Notochordal process
Notochord
Neural Tube
Brain Spinal cord 21

22. SUBDIVISION OF INTRAEMBRYONIC
MESODERM
 Paraxial Mesoderm
 Lateral plate Mesoderm
 Intermidate Mesoderm
22

23. Paraxial mesoderm
Somitomeres (form bone in muscles in head region)
Somites
Sclerotome Dermatome Myotome
Vertebral column
Ribs
Dermis
Sub cutaneous
tissue
Striated muscle
Occipital Somites-
Muscle of tongue
23

24. LATERAL INTRAEMBRYONIC
MESODERM
 Spaces appear in this layer which later on join and
form intraembryonic coelom.
 At exterimities it join with etraembryonic coelom
 Coronal section – lateral plate mesoderm closer
with etcoderm is somatopleuric intraembryonic
mesoderm
 lateral plate mesoderm closer with endoderm is
splanchopleuric intraembryonic mesoderm
 Give rise to 3 cavities – pericardial cavity, pleural
cavity & peritoneal cavity
 Cephalic to coelom in lateral intraembryonic
mesoderm – cavity does not pass from there i.e
somatopleuric layer & splanchopleuric layer does
not get separated – Septum Transversum – future
diaphram
24

25. 25

26. EMBRYONIC FOLDING
 With the embryonic disc becomes folded on itself at
the head and tail ends.
 The head fold is critical to the formation of the
primitive stomatodaeum
 Ectoderm comes through this fold to line the
stomatodaeum
 Stomatodaeum is separated from the gut by
buccopharyngeal membrane.
HEAD FOLD
LATERAL
FOLD
TAIL FOLD
26

27. 27

28. 28

29. EMBRYONIC DISC BEFORE HEAD AND TAIL FOLDS
29

30. AFTER FORMATION OF HEAD AND TAIL FOLDS
30

31. STOMODEUM
 Stomodeum is a depression bounded cranially
by a bulging produced by the brain &
caudally by the bulging produced by
pericardial cavity
 An ectoderm lined depression
 Seperated from the primitive pharynx by the
buccopharyngeal (oropharyngeal) membrane
 The membrane later breaks down &
stomodeum open into pharynx
 Forms the vestibule of oral cavity
31

32. FORMATION OF PHARYNGEAL
POUCHES
 Begin to develop at the 4th week of
development
 These are mesodermal thickening in the
cranial most part of the foregut.
 The mesoderm is arranged in six bars that
run in the side wall of foregut.
 Mesoderm of arches – paraxial & lateral
plate mesoderm
 Each of these bars fuse with the
corresponding ones to form Pharyngeal
arches.
 A total of 6 arches are formed out of which
5 remain as the fifth arch soon
degenerates. 32

33. 33

34. FORMATION OF PHARYNGEAL ARCHES
34

35. BRANCHIALARCHES
(PHARYNGEALARCHES)
 Paired structures
 Develop from cephalic (head) portion
of the neural crest
 Appears as outpouching of mesoderm
on both sides of developing pharynx
(foregut)
 Grow on either side of future head &
neck of developing embryo & fuse at
centre line
 6 pairs
 5th arch rudimentary
35

36.  In interval between 2 adjoining arches, the
endoderm extends outward in the form of a pouch
called endodermal/ pharyngeal pouches
 This try to meet ectoderm – dips into this
intervals as ectodemal cleft
36

37. Structures seen in
Pharyngeal Arch
• Skeletal element (Cartilage)
• Striated Muscle
• Nerve
• Aortic arch
37

38. 38

39. 39

40. DERIVATIVES OF FIRST PHARYNGEAL
ARCH
 2 portions
 Dorsal - Maxillary process
giving rise to premaxilla, maxilla, zygomatic bone & the part
of temporal bone
 Ventral – Mandibular process, which contains the
MECKEL’s CARTILAGE
During further development, Meckel’s cartilage disappears
except for two small portions at its dorsal end that persist &
form the incus & malleus
40

41. MECKEL’S CARTILAGE
 Cartilage of first arch
 Dorsal end – Incus & Malleus(of middle ear)
 Ventral end – surrounded by developing mandible
 Cartilage from middle ear to mandible disappears,
but its
 Sheath (perichondrium) forms:1)Anterior ligament
of malleus
2)Sphenomandibular ligament
 Mesenchyme – bones of face i.e maxilla,
mandible, zygomatic bone, palatine bone, part of
temporal bone
41

42. DERIVATIVES OF SECOND ARCH
(HYOID ARCH)
Cartilage of Second Arch (reichert’s cartilage) forms:
Dorsal end of cartilage:- Stapes
Styloid process
Ventral part of cartilage:- Smaller (lesser) cornu of hyoid bone
Superior part of body of hyoid bone
 Part between dorsal and ventral parts disappears, but its
Perichondrium(sheath):- Stylohyoid ligament
42

43. DERIVATIVES OF THIRD ARCH
The cartilage of third arch forms:
Ventral part of cartilage:-
Greater cornu of hyoid bone
Lower part of the body of hyoid bone
 Dorsal part disappears
43

44. 44

45. DERIVATIVES OF FOURTH AND SIXTH ARCHES:
The cartilages of Larynx are derived from fourth and sixth arches:-
Thyroid cartilage
Cricoid cartilage
Corniculate cartilage
Cuneiform cartilage
Arytenoid cartilage
Thyroid ligament
45

46. PHARYNGEAL POUCHES
 Formed on endodermal side
 Between pharyngeal arches
 5 pairs
 Last one of these is atypical & is considered
as a part of 4th
46

47. Fifth pharyngeal pouch
Last one to develop & is considered
a part of 4th pouch
Leads to development of
Ultimobranchial body which in
future leads to development of
Thyroid gland
Third pharyngeal
pouch
• Dorsal- proliferates to
form Inferior parathyroid
gland
• Ventral- forms Thymus
Fourth pharyngeal
pouch
Dorsal-Epithelium of
this pouch forms the
Superior parathyroid
gland
First pharyngeal pouch
Dorsal-stalk like diverticulum
Tubo tympanic recess
1)proximal part-Auditory tube
2)distal part-Middle ear
cavity
Ventral - Tongue
Second pharyngeal
pouch
Dorsal- Tubo tympanic
recess
Ventral-The epithelial lining
forms the primordium of the
palatine tonsil
47

48. 48

49. PHARYNGEAL GROOVES(CLEFTS)
• Form lateral ectodermal surface of neck region
that separate arches
• 5 week embryo;4 pharyngeal clefts of which
only one contribute to the development of the
definitive structure of embryo
• Dorsal part -1st pharyngeal groove forms the
External auditory meatus which is the only
invagination on the side of the head
• The 2nd, 3rd, 4th pharyngeal grooves merge
together-the Cervical sinus which with further
development disappears
49

50. 50

51. 51

52. 52

53. 53

54. DEVELOPMENT OF FACE
Dr. DISHIKA BHAGWANI
PG 1
DEPARTMENT OF
PEDODONTICS &
PREVENTIVE DENTISTRY
54

55. CONTENT
PART 1:-
• Fertilization, cleavage
• Formation of morula, blastocyst
• Formation of germ layers
• Formation of procordal plate , primitive streak & intraembryonic mesoderm
• Formation of notochord
• Sub-division of intraembryonic mesoderm
• Embryonic folding
• Stomodeum
• Formation of pharyngeal arches, pouches & clefts
• Derivatives of pharyngeal arches, pouches & clefts
55

56. PART 2:-
• MAXILLA
• MANDIBLE
• PALATE
• NOSE
• LIP
• CHEEK
• TONGUE
• TOOTH
• EYE
• EAR
• CONGENITAL ABNORMALITIES
• REFERENCES 56

57. 57

58. DEVELOPMENT OF FACE
 Between 4-8 weeks I.U
 Mandible is the first to form (4th week)
 The facial proportions develop during the fetal
period (9th week to birth)
 During infancy & childhood, following
development of teeth & paransal sinuses, facial
skeleton increases in size & contribute to the
definitive shape of face
58

59. DEVELOPMENT OF FACE
 4th week, 2 prominent bulgings appear,
separated by stomatodeum. (head bulge
& pericardium bulge)
 Each side of stomatodeum bounded by
1st arch
 Mesenchyme covering developing
forebrain proliferates & form downward
projection called frontonasal process
that overlaps upper part of stomatodeum
 1st arch dorsal end gives rise to maxillary
process (paired)
 1st arch vental end give rise to
mandibular process (paired)
59

60. 60

61.  Early in the 4th week
 5 primordial swellings
1. One frontonasal process
2. Right & left maxillary process
3. Right & left mandibular process
Prenatal growth of maxilla
61

62. 62

63. DEVELOPMENT OF
NOSE
63

64. DEVELOPMENT OF NOSE
 By the end of 4th week, bilateral oval shaped
ectodermal thickenings called ‘Nasal Placodes’
appear on each side of the lower part of frontonasal
prominence
 Proliferation & migration of ectomesenchyme for
formation of primitive nasal cavities
 Nasal placodes are primordia of nose & nasal
cavities
64

65.  At 28 days, localised thickenings
develop within ectoderm of frontal
process above to opening of
stomodeum – Olfactory placodes/
nasal placodes
 The placodes soon sink below the
surface and continue with
stomatodeum below. This is now called
nasal pits. This are horse-shoe shaped
swellings
 Olfactory placodes  Nasal pits
65

66. 66

67. Edge of each pit is raised above the surface
Horse shoe swelling
 Lateral aspect – Lateral nasal process
 Medial aspect - Medial nasal process
Fronto Nasal process
 Region of frontal prominence
 Becomes narrower
 Deeper part forms Nasal Septum
 Mesoderm heaped up – prominence of
nose
67

68.  The placodes now lie in the floor of the
depression called ‘nasal pits’
• By the end of 6th week, nasal pits deepen
& form nasal sacs
• Nasal cavities - formed by extension of
nasal pits
• Each nasal sac grows dorsocaudally,
ventral to the developing brain
68

69. 69

70. 70

71.  Initially nasal sacs are separated from oral
cavity by oronasal membrane
 The oronasal membrane ruptures by 7th week,
communicating the primitive nasal cavities
with oral cavity
 These communications are called primitive
choncae & are located posterior to primary
palate
 After development of secondary palate,
choncae change their position & become
located at the junction of nasal cavity & the
pharynx
71

72.  The superior, middle, inferior choncae
develop on lateral wall of each nasal cavity
 The ectodermal epithelium in the roof of
each nasal cavity becomes specialized as the
olfactory epithelium
72

73. DEVELOPMENT OF
LIP
73

74. • Medial growth of maxillary
process pushes median nasal
process toward the midline &
finally fuses with anatomic
counterpart from opposite side.
• The upper lip is formed from
maxillary process of each side &
the frontonasal process.
DEVELOPMENT OF UPPER LIP
74

75. 75

76. • Mesoderm of lateral part of lip is - maxillary process.
• Mesoderm of median part of lip is - frontonasal process
• Overlying skin - ectoderm of same process
• The mesenchyme from the 1st & 2nd pairs of pharyngeal arches
invade the facial prominences & give rise to the muscles of
mastication & muscles of facial expression respectively
76

77. DEVELOPMENT OF LOWER LIP
 The mandibular process of two
sides grow towards each other
& fuse in midline
77

78. 78

79. DEVELOPMENT OF CHEEK
• After formation of upper lip & lower lips the stomodeum becomes
broader
• Maxillary prominence continue to increase in size & laterally merge with
mandibular prominences to form the CHEEK
79

80. INTER MAXILLARY SEGMENT
 Gives rise to
1)Philtrum of lip
2)Premaxillary part of the maxilla, that bears the
upper 4 incisors & the associated gums
3)Primary palate (region of hard palate just posterior
to upper incisors)
During 6th week the medial nasal process enlarge, grow
medially & merge with each other in the midline to form the
inter maxillary segment
80

81. DEVELOPMENT OF PALATE
(PALATOGENESIS)
 Begins at the end of 5th week
 Gets completed by end of 12th week
 Most critical period for development of palate is
from end of 6th week to the beginning of 9th
week
Palate develops from –
1. 2 palatal process
2. Primitive palate
81

82. IMAGE
82

83. Definitive palate formed by fusion of
Palatal process + posterior
part of primitive palate
2 palatal
process fuses
Medial edges of palatal
process + nasal septum 83

84.  Fusion with nasal septum begins anteriorly during 9th week, extends
posteriorly & is completed by 12th week
 Mesoderm in palate undergoes Intramembranous ossification
 Only in anterior part - hard palate
 Posterior part - soft palate
 Frontonasal process - premaxilla
84

85. PALATE FORMATION
• Maxillary components
of 1st pharyngeal arch
• Frontonasal process
Primary
palate
• Hard palate
• Soft palate
Secondary
palate 85

86. DEVELOPMENT
OF TONGUE
86

87. 87

88. 88

89. DEVELOPMENT OF TONGUE
 4 weeks
 Medial most part of 1st arch proliferates
& form 2 lateral lingual swelling
 One medial swelling – TUBERCULUM
IMPAR
 Behind Tuberculum impar -epithelium
proliferates form a downgrowth from
(thyroglossal duct) from which thyroid
develops.
 Foramen Caecum
89

90.  Hypobranchial eminence – midline
swelling in medial ends of 2nd 3rd 4th
arch.
 Cranial part - Copula (2nd 3rd )
 Caudal part (4th) - Epiglottis
 Anterior 2/3rd by 2 lingual swellings
and tuberculum impar
 Porterior 1/3rd by cranial part of
hypobranchial eminence
90

91. 91

92. POSTNATAL GROWTH OF MAXILLA
Displacement
Primary
Secondary
Growth at suture
Frontonasal suture
Fronto maxillary
suture
Zygomatic
temporal suture
Zygomatic
maxillary suture
Pterygopalatine
suture
Surface
remodelling
Orbital rim
Maxillary
tuberosity
Lateral wall of
nose
Floor of nasal
cavity
Zygomatic bone
Alveolar margins
Maxillary tuberosity
grows posterioly
Maxilla moves
forward
92

93. POSTNATAL GROWTH OF MAXILLA
Displacement
Primary
Secondary
Growth at suture
Frontonasal suture
Fronto maxillary
suture
Zygomatic
temporal suture
Zygomatic
maxillary suture
Pterygopalatine
suture
Surface
remodelling
Orbital rim
Lateral wall of
nose
Floor of nasal
cavity
Palate
Zygomatic bone
Maxillary
tuberosity 93

94. Prenatal growth of Mandible
 4th week
 MECKEL’s CARTILAGE 41st – 45th day
 Major portion disappears
 Remaining part develops into:-
1. Mental ossicles
2. Incus malleus
3. Spine of sphenoid
4. Anterior ligament of malleus
5. Spheno mandibular ligament 94

95. 95

96.  Single ossification centre for
each half of mandible
 Bifurcation of inferior alveolar
nerve
 At 7th week Intramembranous
ossification
 Rapid spread of ossification
dorsally & ventrally forms body
& ramus of mandible.
 Ossification stops – later Lingula
96

97. Endochondral Bone Formation
10th -14th week, secondary
accessory cartilages form
1. Condylar process
2. Coronoid process
3. Mental region
97

98. CONDYLAR PROCESS
 Cone shape cartilage seen at
10th week
 Starts osification at 14th week
 Later migrates inferiorly to fuse
with ramus by about 4 months
 Most of cartilage is replaced by
bone by middle of fetal life, but
upper end persists into
adulthood that acts as both
growth as well as articular
cartilage
98

99. CORONOID PROCESS
 Cartilage seen in 10-14th week IU
 Gets incorporated into expanding intramembranous bone of ramus and
disappears before birth
 Cartialge on either side of symphysis ossify in 7th month IU
MENTALREGION
99

100. POSTNATAL GROWTH OF
MANDIBLE
Bone deposition & resorption
1. Ramus
2. Body of mandible
3. Chin
4. Lingual tuberosity
5. Angle of mandible
6. Alveolar process
7. Condyle
8. Coronoid process
100

101. Angle of
mandible
Mental
foramen
Alveolar
ridge
101

102. DEVELOPMENT OF EYE
102

103. Optic
vesicle
• Neural plate
• Optic sulcus
• Optic vesicle
• Optic stalk
Lens
vesicle
• Surface
ectoderm
• Lens
placode
• Lens vesicle
Optic cup
• Optic vesicle
• Optic cup
DEVELOPMENT OF EYE
103

104. Optic
vesicle
• Neural plate
• Optic sulcus
• Optic vesicle
• Optic stalk
Lens
vesicle
• Surface
ectoderm
• Lens
placode
• Lens vesicle
Optic cup
• Optic vesicle
• Optic cup
DEVELOPMENT OF EYE
104

105.  5th week
3 sources:
1. Neuro ectoderm of forebrain – retina, optic nerve
2. Surface ectoderm of head – lens
3. Mesoderm between these layers – eye muscle & vascular tissues
First appearance of eye – Lens placode
Lens
placode
Sinks below
surface
Eyeball
produces
buldging105

106. DEVELOPMENT OF EAR
106

107. 107

108. EXTERNAL EAR
External acoustic meatus:-
Develops by deepening of dorsal end of 1st
pharyngeal cleft
Pinna or Auricle:-
Six mesenchymal hillocks- Auricular hillocks
develop from 1st & 2nd pharyngeal arch
Tympanic membrane - eardrum
DEVELOPMENT OF EAR
108

109. MIDDLE EAR
Develops from tubo tympanic recess derived from 1st
pharyngeal pouch
Ossicles – Malleus
Incus
Stapes
Eustachian tube – middle ear to back of nose
INTERNAL EAR
Otic placode
1. Cochlea
2. Vestibule
3. Semicircular canal
109

110. PARANASAL SINUSES
 During late fetal life the remainder develops after birth
 They form as outgrowths or diverticula of walls of nasal cavities & become
air filled extensions of nasal cavities in the adjacent bone
1. Frontal 3-4 months I.U
2. Ethmoidal 4 months I.U
3. Maxillary Develops at 10 weeks of I.U
4. Sphenoidal 4 months of I.U
110

111. DERIVATIVES OF FACIAL
COMPONENTS
FRONTONASAL PROMINENCE forms-
1. Forehead & the bridge of nose
2. Frontal & nasal bones
MAXILLARY PROMINENCES forms-
1.Upper cheek regions & most of the upper lip
2.Maxilla, zygomatic bone, secondary palate111

112. Mandibular prominence fuses-
1. Chin, lower lip, & lower cheek regions
2. Mandible
Lateral nasal prominence forms- Alae of nose
Medial nasal prominences form- Intermaxillary segment112

113. MUSCULAR
DEVELOPMENT
 During 5th week, myoblast proliferate within the
mandibular arch
 By the 7th week, cells migrate & differentiate into 4
MOM
1. Lateral pterygoid
2. Medial pterygoid
3. Masseter
4. Temporalis
 The muscle cells within the hyoid arch & in the
occipital myotomes undergo proliferation &
migrate anteriorly toward the floor of the mouth to
form muscles of the tongue Muscle cells of the 3rd & 4th arch form the
pharyngeal muscles
1. Stylopharyngeus
2. Cricothyroid
3. Levator palatini
4. Constrictor muscle of pharynx
113

114. CONGENITALANOMALIES
Craniofacial Defects
Crouzan syndrome
Treacher Collin syndromeRobin sequenceDi George anomaly
Hemifacial Microsomia
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115. Developmental defects of TONGUE
Microglossia Macroglossia Ankyloglosia
Fissured tongue
Median rhomboid
glossitis
Benign migratory
glossitis Bifid tongue
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116. Abnormalities in LIP & PALATE
Cleft lip – Unilateral
Bilateral
Cleft palate
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117. Developmental defects of JAW
• Micrognathia
• Agnathia
• Macrognathia
• Facial hemihypertrophy
• Facial hemiatrophy
Developmental defects of NOSE
• Bifid nose
• Proboscis
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118. Defects in development of EAR
Preauricular pits & appendages
Malleus/incus fixation
Absence of long process of incus
Congenital fixation of stapes
Failure of annular ligament development
Congenital preauricular sinus
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119. Defects in development of EYE
 Cyclopia
 Absence of eye i.e anopthalmia
 Colobomas of eyelids
 Congenital ptosis
 Fusion of eyelids – cryptophtalmos
 Epicanthal fold
 Corneal dermoids
 Congenital glaucoma
 Fraser’s syndrome
 Stromal dystrophy
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120. REFERENCES
 Orbans, textbook of hiostology
 I B Singh, textbook of embryology
 Balaji, textbook of orthodontics
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