prenatal growth and development of face GROWTH Growth may be defined as the normal changes in the amount of a living substance – MOYER Growth refers to an increase in size or number – PROFFIT Growth may be defined as a developmental increase in mass i.e, it is a process that leads to an increase in the physical size of cells, tissues, organs or organisms as a whole – STEWART 1982 “Growth signifies an increase, expansion or extension of any given tissue.” - Pinkham.(1994) Development refers to all the naturally occurring progressive, unidirectional changes in the life of an individual from its existence as a single cell to its elaboration as a multifunctional unit terminating in death. – MOYERS 1988 Development addresses the progressive evolution of a tissue PINKHAM 1994 “Development is a progress towards maturity” – Todd(1931)

2. PRESENTED BY-
DR J R SWAIN

3.  Introduction
 Definitions
 Theories of development
 Embryogenesis
The pre-implantation period
The embryonic period
The fetal period
 Pharyngeal arches, pouches and grooves
 Facial development
CONTENT

4.  Prenatal development of
Mandible
Maxilla
Palate
Tongue
Temporomandibular joint
 Teratogenic effects on embryonic development
 Conclusion
 References
CONTENT

5. GROWTH
Growth may be defined as the normal changes in the amount of a living
substance – MOYER
Growth refers to an increase in size or number – PROFFIT
Growth may be defined as a developmental increase in mass i.e, it is a
process that leads to an increase in the physical size of cells, tissues,
organs or organisms as a whole – STEWART 1982
“Growth signifies an increase, expansion or extension
of any given tissue.” - Pinkham.(1994)
GROWTH

6. Development refers to all the naturally occurring progressive,
unidirectional changes in the life of an individual from its existence
as a single cell to its elaboration as a multifunctional unit terminating
in death. – MOYERS 1988
Development addresses the progressive evolution of a tissue
PINKHAM 1994
“Development is a progress towards maturity” –
Todd(1931)
DEVELOPMENT

7. The human somatic cell contains 46
chromosomes, called as the diploid number.
Out of which 44 are autosomes and the
remaining 2 are sex chromosomes, designated
as X and Y.
The sex chromosomes in females are XX and
in males are XY.
There are two series of division of somatic
cells- MITOSIS and MEIOSIS.
INTRODUCTION

8.  MITOSIS produces the same number of
chromosomes in the resulting daughter cell while
MEIOSIS produces half the number i.e. 23
designated as haploid, with resultant formation of
gametes .
 Development begins with FERTILIZATION, the
process in which the male gamete- the sperm, and the
female gamete- the oocyte, unite to form a ZYGOTE.
INTRODUCTION

9. PRENATAL
Before birth
POSTNATAL
After birth

10. a. Prenatal growth
1. Period of ovum: From time of fertilization till 2nd
week.
2. Period of embryo: from 2nd week till 8th week
3. Period of fetus: from 9th week onwards till birth
b. Postnatal growth
c. Maturity
d .Old age
GROWTH IS DIVIDED INTOPre-natal
Ovum
1-14th day
Embryo
14th – 56th day
Fetus
56th – 280th day

11. 1)Growth-this is the increase in the size by cell division
2)Morphogenesis-this is the development of form
3)Differentiation-includes the maturation of physiological processes
Folding of the embryo:-
The trilaminar germ disc is flattened and pear-shaped .The cells in the central part
grow more rapidly than those at the periphery.Because of the lack of space ,the
embryo undergoes head fold ,tail fold and lateral folds by the end of the third week
.This converts the flattened germ disc into a cylindrical embryo.
PHASES OF DEVELOPMENT

12. The growth is strongly influenced by the genetic factors ,but it also can be
significantly affected by the environment in the form of nutritional status, degree
of physiological activity ,health or illness and a number of similar factors.
Three main theories in the recent years have attempted to explain the
determinants of craniofacial growth:
(1)Bone ,like other tissues ,is the primary determinant of its own growth,
(2)Cartilage is the primary determinant of skeletal growth , while the bone
responds secondarily and passively
(3)The soft tissue matrix in which the skeletal elements are embedded as the
primary determinant of growth
THEORIES OF DEVELOPMENT

13. EVENTS IN PERIOD OF OVUM
Morulla formation
3rd day
Blastocyst
4th & 5th day
Fertilization

14. FERTILIZATION

15. Restoration of diploid number of chromosomes
Determination of sex
Initiation of cleavage
RESULTS OF FERTILIZATION

16. PREIMPLANTATION PERIOD
( 1ST WEEK )
Day 1– fertilization
Day 2 –2 cell stage
Day 3 – MORULA
Day 4 – early blastocyst
Day 5 -- late blastocyst

18. Embryo by process of cleavage reaches 16 celled stage
Looks like a mulberry that’s why called so
Zona pellucida still presents
Contains outer rim of cells called Trophoblast
Inner cell mass called Embryoblast
MORULA

19. As the cell mass divides, it enlarges and gains a fluid
filled cavity termed the blastocele(5th day).
 The blastocoele separates the cell into 2 parts:
-An outer cell layer, the trophoblast, and
-An inner cell mass, the embryoblast.
As the fluid quantity increases it acquires the shape of cyst
Trophoblast cells become flattened and embryoblast cells
get attached to one side
Now it is called blastocyst and cavity is called Blastocoele
FORMATION OF BLASTOCYST

22. Trophoblast sticks to uterine
endometrium
Blastocyst goes deeper into
uterine mucosa until whole of
it lies in thickness of
endometrium---Interstitial
Implantation
IMPLANTATION ( 8TH DAY )

23. SECOND WEEK
II

24. is known as week of two’s , there is differentiation of:
TROPHOBLAST INTO:
-CYTO TROPHOBLAST
-SYNCYTIO TROPHOBLAST
EMBRYOBLAST INTO:
EPIBLAST
HYPOBLAST
TWO CAVITIES:
AMNIOTIC CAVITY
YOLK SAC CAVITY
SECOND WEEK OF PRENATAL
DEVELOPMENT

25. GERM DISC AT THE END OF 2ND
WEEK

26. THIRD WEEK
III

27. 1. Gastrulation
2. Formation of the notochord
3. Neurulation
3RD WEEK OF PRENATAL DEVELOPMENT
TRILAMINAR GERM DISC

28. • Most characteristic event occuring during the third week of
gestation is Gastrulation ,which establishes the germ layer.
• At the beginning of the 3rd week, a Primitive Streak forms within
the bilaminar disc
• This furrowed rod shaped thickening results from increased
proliferation of cells in the midline
• Primitive streak causes the disc to have bilateral symmetry with a
right and left half.

29. GASTRULATION: TRILAMINAR
GERM DISC
Embryonic disc forms prochordal plate & primitive streak (14th day)

30. 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 the
cells that form the
notochordal process.

32. Formation of 3rd germ layer – Intraembryonic-mesoderm
(16th day)
Intraembryonic-mesoderm

33. Age ( in days) Developmental events
2 2 cell stage
3 Morula formed
4 Blastocyst formed
8 Bilaminar disc is formed
14 Prochordal plate and primitive streak is seen
16 Intra embryonic mesoderm is formed
17 Notochordal process appears
21 Neural groove seen, head fold begins to form
23 Closure of neural tube

34. EMBRYO PERIOD
(3RD TO 8TH WEEK)

35. Further development of Embryonic Disc
3rd week

36. Formation of Notochord By Day 19

37. Development of mesoderm into 3 aggregation
(Transverse section)
Day 17
Day 21Day 20
Day 19

38.  Ectomesenchymal tissue termed neural crest
cells appears in the intermediate zone between
the surface ectoderm and the neural tube during
neurulation.
 These are Pleuripotent cells.
 They can undergo Migration and Cyto-
differentiation .
NEURAL CREST
CELLS
3
1
2

39. Connective tissue-
- Ectomesenchyme of facial prominences and branchial
arches
- Bones and cartilages of facial visceral skeleton
- Dermis of face and neck
- Stroma of salivary ,thymus ,thyroid, parathyroid and pituitary
gland
- Corneal mesenchyme
- Aortic arch arteries
-Dental papilla
-Portions of periodontal ligament ,Cementum
DERIVATIVES OF NEURAL
CREST CELLS

40. Muscle tissue
-Ciliary muscles
-Covering connective tissue of branchial arch muscles
Nervous tissue
-Leptomeninges.
-Schwann sheath cells

41. Sensory ganglia
Autonomic ganglia.
Spinal dorsal root ganglia.
Sensory ganglia.
ANS
Sympathetic ganglia.
Parasympathetic ganglia.

42. Gives rise to the epidermis and associated structures (skin,hair,nail),
nervous system and various other structures
ECTODERM

43. - smooth muscular coats,
- connective tissues,
- vessels supplying tissues & organs.
- blood cells,
- bone marrow,
- the skeleton,
- striated muscles ,
- reproductive & excretory
organs.
MESODERM

44. Source of epithelial linings of the respiratory passages and digestive
tract, including the glandular cells of associated organs such as the
liver and pancreas.
ENDODERM

45.  Third week of development is highly sensitive stage for teratogenic
insult.
 High doses of alcohol at this stage kill cells in the anterior midline of
the germ disc- producing deficiency of the midline in craniofacial
structure and resulting in HOLOPROSENCEPHALY.
 CAUDAL DYSGENESIS – insufficient mesoderm.
 SACROCOCCYGEAL TERATOMAS – tumors associated with
gastrulation
CLINICAL
SIGNIFICANCE

46. Cephalocaudal folding at various stages of
development ( sagital midline section)
46
End of I
month

47. FOURTH WEEK
 Folding of embryo
 3 germ layers – major organs
 3 pharyngeal arches present
 Upper & lower limb buds,dental
lamina, otic pits,lens placode
 C shaped curve

48. FIFTH WEEK
 Head grows- rapid develop. Of
brain
 Face contacts heart
prominence
 Hand plate, lower buds appear
 Spontaneous movement

49. 6TH WEEK
 Primitive nose philtrum
 Primary Palate
 EAM, auricle
 Retinal pigment in eye
 Head more bent
 Reflex response to touch
 Tooth buds

50. 7TH WEEK
 Umbilical herniation
 Future digits

51. 8TH WEEK
 Digits of hand short, webbed
 Eyes open
 Scalp vascular bed
 Tail

52. The Fetal Period
(3rd month to Birth)

53. 9-12 WEEKS
 External genitalia becomes
distinguishable.
 Erythropoises initially begins in the liver,
and later in the spleen.
 By the end of 12th week primary
ossification appear in the skull and long
bones.
 Fetal waste products are transferred into
the maternal circulation through the
placenta.

54. 13TH-15 WEEKS
 Breathing and swallowing motions
appear.
 Crown calcification of primary incisor
and first molars begins.
 Bones are clearly visible on
radiographs of maternal abdomen by
16th week.
 Slow eye movement occur at 14th
week (Birnholz 1981).

55. 17-20 WEEKS
 Primordial follicles form oogonia in
ovaries
 Calcification of canines and second
molars begins.
 Myelination of nerves begins
 Fingernails and toenails begin to
appear.
 Fetus shows hiccups, thumb sucking,
and kicking.

56. 21ST-25TH WEEK
 The eyebrows and eyelashes are well
formed.
 The skin becomes less transparent as fat
begins to deposit.
 Breathing-like movements become regular.
 There is little chance for survival outside the
uterus.

57. 26-29 WEEK
 The central nervous system is developed
enough to control some body functions.
 The eyelids open, close and can perceive
light.
 The lungs have further matured and
breathing is possible.
 The unborn child exercises muscles by
kicking and stretching.

58. 31ST-34TH WEEK
 Subcutaneous fat is deposited
 Fetus appears reddish
 Rhythmic breathing movements occur, but the
lungs are not yet matured.
 At this point the survival rate is above 95% if
the baby is born.

59. 34-38 WEEK
 Fat develops rapidly resulting in red
smooth plump appearance.
 In this period building up of tissues take
place.
 Hair covering the entire body.
 Organ systems function actively.

60. WELCOME
CONGRATS
ON YOUR
NEW ARRIVAL

62. PRE-NATAL
FACIAL DEVELOPMENT

63. DEVELOPMENT OF FACE
Mesenchymal tissueBranchial cleft
These arches appear in the 4th and 5th weeks
Development of the head and neck is formed by
the pharyngeal or branchial arches.
Branchial
arch

64.  Pharyngeal arches appear sequentially on the
ventrolateral surface of the head and neck region.
 The exterior surface of the arches is covered by
ectoderm.
 The ectoderm between the arches forms
the pharyngeal clefts or grooves
endoderm

66. Each pharyngeal arch is charrecterized by its own muscular components ,their
nerve component and it’s own arterial component.
PHARYNGEAL ARCH

67. Consists of two portions:
Dorsal:-also known as the maxillary process , giving rise to premaxilla ,maxilla, zygomatic
bone and part of the temporal bone.
Ventral:- also known as the mandibular process , which contains the MECKEL’S
CARTILAGE. During further development , Meckel’s cartilage disappears except for two small
portions at it’s dorsal end that persist and form the Incus and Malleus.
Musculature of the 1st pharyngeal arch includes the muscle of mastication
(temporalis,masseter,lateral pterygoid and medial pterygoid),anterior belly of the
digastric,mylohyoid,tensor tympani and tensor palatini.
FIRST PHARYNGEAL ARCH

68.  Nerve supply to the muscles of the 1st arch is provided by Mandibular
branch of Trigeminal nerve.
 Sensory supply of the skin of the face is provided by Ophthalmic ,
Maxillary and Mandibular branches of the Trigeminal nerve.
 Muscles of the different arches do not always attach to the bony or
cartilagenous components of their own arch but sometimes migrate into
surrounding regions. The origin of these muscles can be traced ,since their
nerve supply is derived from the arch of origin.

69. The cartilage of the second arch (hyoid arch)is called as REICHERT’S
CARTILAGE which gives rise to the stapes ,styloid process of the temporal
bone , stylohyoid ligament, the lesser horn and upper part of the body of the
hyoid bone .
SECOND PHARYNGEAL ARCH

70.  Muscles of the hyoid arch are the stapedius , stylohyoid, posterior belly of
digastric, auricular and muscles of facial expressions.
 Facial nerve- the nerve of the 2nd arch supplies all these muscles.

71.  The cartilage of this arch produces the lower part of the body and the
greater horn of the hyoid bone.
 Muscle of this arch is the Stylopharyngeus muscle which is innervated by
the Glossopharyngeal nerve.
THIRD PHARYNGEAL ARCH

72.  Cartilagenuos components of the 4th and 6th pharyngeal arches fuse to
form the thyroid, cricoid, arytenoid, corniculate and cuneiform cartilages
of the larynx.
 Muscles of the fourth arch are supplied by the Superior laryngeal branch
of the Vagus nerve and the intrinsic muscles of the larynx are supplied by
Recurrent laryngeal branch of Vagus nerve
FOURTH AND SIXTH
PHARYNGEAL ARCH

73.  The human embryo has five pairs of pharyngeal pouches.
 The last one of these is atypical and is considered as a part of the 4th
 First pharyngeal pouch:
 It forms a stalk like diverticulum –the tubotympanic recess;
 one side of this comes in contact with the external auditary meatus
 The distal aspect of this widens in a sac like structure ,the primitive
tympanic or middle ear cavity
 The proximal part remains narrow forming auditary (eustacian)tube.
 The lining of the tympanic cavity forms the tympanic membrane or the
eardrum
PHARYNGEAL POUCHES

74.  Second pharyngeal pouch:
 The epithelial lining forms the primordium of the palatine tonsil.
 Third pharyngeal pouch:
 It is characterized by a dorsal and a ventral wing .The dorsal wing
proliferates to form the inferior parathyroid gland and the ventral wing
forms the thymus

75.  Fourth pharyngeal pouch:
 Epithelium of the dorsal wing of this pouch forms the superior
parathyroid gland.
 Fifth pharyngeal pouch :
 The 5th pouch is the last one to develop and is considered to be a part of
the 4th pouch. This pouch leads to the development of thyroid gland.

76.  The 2nd ,3rd & 4th pharyngeal grooves merge together to form the cervical
sinus which with further development disappear.
 The 1st pharyngeal groove forms the external auditory meatus which is the
only invagination on the side of the head.
PHARYNGEAL GROOVES

77.  The 5 week embryo is characterized by the presence of 4 pharyngeal clefts
of which only one contribute to the development of the definitive
structure of the embryo.
 The dorsal part of the 1st cleft gives rise to the external auditory meatus
PHARYNGEAL CLEFT

78. CLINICAL
SIGNIFICANCE
(branchial arch anomlies)

79. Classification:
Unilateral-- Hemifacial microsomia or
Goldenhar’s syndrome
Bilateral-- Mandibulofacial dysostosis

80. HEMIFACIAL
MICROSOMIA
Features:
 assymetrical anamolies
of pinna & middle ear
 Deficiencies in malar,
temporal & ramus
 Facial paresis
 Pseudomacrostomia

81. MANDIBULOFACIAL
DYSOSTOSIS

82. Branchial fistulas :
When the 2nd pharyngeal arch fails to grow caudally over the 3rd and the 4th
arches , leaving remnants of the 2nd 3rd &4th clefts in contact with the surface
by a narrow canal.
Internal branchial fistulas :
It is very rare and in this the cervical sinus is connected to the lumen of the
pharynx by a small canal which usually opens in the tonsillar region.

83. DERIVATIVES OF
FACIAL COMPONENTS

84. The frontonasal
prominence forms the:
 Forehead and the bridge of
the nose
 Frontal and nasal bones
The maxillary prominences form the:
 Upper cheek regions and most of the upper lip
 Maxilla, zygomatic bone, secondary palate

85. The mandibular processes
fuse and form the:
 Chin, lower lip, and lower
cheek regions
 Mandible
The lateral nasal prominences form the ala of the nose
The medial nasal prominences fuse and form the
intermaxillary segment

86.  The development of the face occurs mainly between 5 – 8 weeks
 The lower jaw (mandible) is the first to form (4th week)
 The facial proportions develop during the fetal period (9th week to birth)
 During infancy & childhood, following the development of teeth and
paranasal sinuses, the facial skeleton increases in size and contribute to the
definitive shape of the face
CHRONOLOGICAL DEVELOPMENT OF
DIFFERENT PARTS OF THE HEAD

87. THE FACE and ORAL REGION
a. Face consists of a few primordial tissue
masses partially surrounding the future
oral region.
b. The oral cavity (stomodeum) is an
ectodermal depression separated from the
foregut by the Oral plate formed of ectoderm
on one side and endoderm on the other.
c. The face is dominated by the frontal
prominence of the overhanging forebrain.
d. Laterally, the maxillary processes of the
1st branchial arch are visible.
stomodeum
4 weeks
5.5 weeks
5 weeks
6 weeks
7 weeks 8 weeks
maxillary
process
mandibular
arch
nasomedial
process
philtrum

88. 1. On either side of the frontal prominence are
horseshoe-shaped elevations are found
around the nasal placodes.
a. Medial limbs are nasomedial processes
b. Lateral limbs are nasolateral processes
2. Growing toward midline are the maxillary
processes, approaching mandibular arches and
merging with them at the angle of the mouth.
a. Maxillary processes grow to crowd the nasal
processes closer together.
b. Nasomedial processes grow quickly, pushing
the frontal prominence , then fuse with the
maxillary processes to complete the arch of the
upper jaw.
c. Nasomedial tissues give rise to philtrum of lip
stomodeum
4 weeks
5.5 weeks
5 weeks
6 weeks
7 weeks 8 weeks
maxillary
process
mandibular
arch
nasomedial
process
philtrum

89. These bulging are separated by the stomotodeum. The floor of
stomatodeum is formed by the buccopharyngeal membrane, which
separates it from the foregut.
FORMATION OF FRONTAL PROCESS
Soon mesoderm covering the
developing forebrain
proliferates and forms a
downward projection that
overlaps the upper part of the
stomatodeum. This downward
projection is called
Frontonasal Process.

90. The first arch, which is formed, gives rise to the
Mandibular Process. The mandibular process gives off
a bud from its dorsal end. This bud is called the
Maxillary Process. It grows ventro-medially cranial to
main part of the arch.

91. • The single frontonasal
prominence ventral to the
forebrain
• The paired maxillary
prominences develop from
the cranial part of first
branchial arch
• The paired mandibular
prominences develop from
the caudal part of first
branchial arch
Lateral view

94. DEVELOPMENT OF MAXILLA
DEVELOPMENT OF MANDIBLE
DEVELOPMENT OF NOSE
DEVELOPMENT OF PALATE
DEVELOPMENT OF EAR
DEVELOPMENTOF EYE
DEVELOPMENT OF LIP
DEVELOPMENTOF TONGUE

95. DEVELOPMENT OF
MAXILLA

96. Maxilla arises from a single center of ossification in the mesenchyme
of the maxillary process of the 1st arch
Centre of ossification is associated with the cartilage of nasal
capsule
The centre of ossification appears in the angle between the division
of an nerve (i.e. where the anteriosuperior dental nerve is given of
from the inferior orbital nerve) just above the canine tooth dental
lamina
DEVELOPMENT OF MAXILLA

97. Ossification spreads in to the palatine process to form hard palate
The medial alveolar plate develops from the junction of the palatal
process & main body of the forming maxilla
Elements of maxilla to develop

98. DEVELOPMENT OF MAXILLA
During the initial 2 weeks
the maxillary prominences
continue to increase in size .
The cleft between the medial nasal prominences and the
maxillary prominence is lost.
Simultaneously they grow in a
medial direction thereby
compressing the medial nasal
prominences toward the midline.

99. Initially the maxillary and the lateral nasal prominences are separated by a
deep furrow ,the nasolacrimal groove.
The nasolacrimal duct then runs from the medial corner of the eye to the
inferior meatus of the nasal cavity.
The maxillary prominence then enlarge to form the cheek and maxillae .

100. DEVELOPMENT OF
NASOLACRIMAL DUCT
NASOLACRIMAL
DUCT
– connects anterior
eye to nasal cavity
- Develops as solid
cord
from medial angle of
eye to nasal cavity
- becomes canalized.Obstructed Duct - failure of duct to
canalize;
is opened surgically for tears to drain to
nasal cavity

101. DEVELOPMENT OF
MANDIBLE

102. DEVELOPMENT OF MANDIBLE
Derived from ossification of an osteogenic membrane at 36
to 38 days of development
At 6th week, a single ossification center for each half of
mandible arises at bifurcation of inferior alveolar nerve

103. b/w 10th -14th weeks, secondary accessory cartilages
appear to form in head of condyle, part of coronoid process
and mental protruberance

105. PARTS OF MANDIBLE DERIVED FROM
INTRAMEMBRANOUS OSSIFICATION
• Whole body of mandible except the anterior part
• Ramus of mandible as far as mandibular foramen
ENDOCHONDRAL OSSIFICATION
• Anterior portion of the mandible (symphysis)
• Part of ramus above the mandibular foramen
• Coronoid process
• Condylar process

106. FATE OF MECKEL’S CARTILAGE
Dorsal end ossifies to form:
malleus & incus
Disappears by 24th week
after conception
Parts transform into:
sphenomandibular
ant. Malleolar ligament
Ventral end forms accessory
endochondral ossicles

107. MANDIBLE IS MEMBRANE BONE DEVELOPED IN RELATION TO THE
NERVE OF THE 1ST ARCH & ALMOST INDEPENDENT OF MECKEL’S
CARTILAGE. THE MANDIBLE HAS NEURAL, ALVEOLAR &
MUSCULAR ELEMENTS & ITS GROWTH IS ASSISTED BY THE
DEVELOPMENT OF SECONDARY CARTILAGES

108. •Ascending ramus of neonatal
mandible is low and wide.
•The coronoid process is
relatively large and projects well
above the condyle.
•Body is merely an open shell
containing the buds partial crown
of deciduous teeth.
•Mandibular canal runs low.
MANDIBLE AT BIRTH

109. 109
At birth Adult Old age
1.Mental
foramen
Nearer the lower border. Midway between upper and lower
borders.
Nearer the upper
border.
2.Angle of the
mandible
obtuse (nearer180°) right angle (about 90°). obtuse (nearer140°).
3. Coronoid
&
condyloid
processes
Coronoid process is
larger and above the
level of condyloid
process.
Condylar process is above the level of the
coronoid process.
Condyloid process is
above the level of the
coronoid process but in
extreme old age it is
bent backwards.
4. Mandibular
canal
Lies a little above
the level of the
mylohyoid line.
Runs nearly parallel with the
mylohyoid line.
Runs close to the upper
or alveolar border.

110. DIFFERENTIAL GROWTH-
During fetal life
8 weeks - Mandible > Maxilla
11 weeks - Mandible = Maxilla
13 – 20 weeks -Maxilla > Mandible
At birth
Mandible tends to be Retrognathic
Early post natal life - Orthognathic

111. ANAMOLIES OF MANDIBLE
1. Agnathia : mandible grossly deficient/ absent
cause: deficiency of neural crest tissue in lower part of face
2. Micrognathia: characteristic of
Pierre robin syndrome
Treacher collins syndrome
Downs syndrome
Turner syndrome
Cause: A central dysmorphogenic mechanism of neural crest production,
migration or destruction

112. 3. Macrognathia:
• Prognathism
• Inherited Condition
• Seen In Hyperpituitarism

113. DEVELOPMENT OF
NOSE

114. 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 the
frontonasal prominence
• Nasal placodes are primordia
of the nose and nasal cavities.
Frontonasal
prominence
Nasal
placode
Nasal
placode

115. • Mesenchymal cells proliferate at
the margin of the placodes and
produce horse-shoe shaped
swellings around these.
• The sides of these swellings are
called ‘medial’ and ‘lateral’ nasal
prominences
• The placodes now lie in the
floor of a depression called
‘nasal pits’
Each lateral nasal prominence is separated from the
maxillary swelling by nasolacrimal groove

116. Embryo: 6 weeks

117. • With the formation of the
medial and lateral nasal
prominences, the nasal placodes
lie in the floor of depressions
called the nasal pits
• By the end of 6th week, nasal
pits deepen and form nasal sacs

118. • Initially the nasal sacs are
separated from the oral cavity
by oronasal membrane.
• The oronasal membrane
ruptures by the 6th week,
communicating the primitive
nasal cavities with the oral
cavity

119. • These communications are called the
primitive choana and are located
posterior to the primary palate
• After the development of the
secondary palate, the choana change
their position and become located at
the junction of nasal cavity and the
pharynx

120. • The nasal septum develops as
a downgrowth from the
internal parts of merged
medial nasal prominences
• Fuses with the palatine
process in 9-12 weeks,
superior to the hard palate

121. • The superior, middle and
inferior conchae develop on
the lateral wall of each nasal
cavity
• The ectodermal epithelium in
the roof of each nasal cavity
becomes specialized as the
olfactory epithelium

122. • The olfactory cells of
the olfactory epithelium
give origin to olfactory
nerve fibers that grow
into the olfactory bulb

124. The medial nasal swellings
enlarge, grow medially and
merge with each other in the
midline to form the
intermaxillary segment
Human embryo: 7 weeks

125. Stenosis of nostrils
Deviation of nasal septum
ANOMALIES OF NOSE

126. DEVELOPMENT
OF PALATE

127. The palate develops from
two primordia:
- The Primary palate
-The Secondary palate
• Begins at the end of the 5th week
• Gets completed by the end of the
12th week
• The most critical period for the
development of palate is from the
end of 6th week to the beginning of
9th week
PALATOGENESIS Development of palate

128. The Primary Palate
• Begins to develop:
 Early in the 6th week
 From the deep part of
the intermaxillary
segment, as median
palatine process
• Lies behind the premaxillary
part of the maxilla
• Fuses with the developing
secondary palate

129. The primary palate represents only a small part lying
anterior to the incisive fossa, of the adult hard palate
Hard palate
Primary
palate
Soft palate
Secondary palate

130. The Secondary Palate
• Is the primordia of hard
and soft palate posterior to
the incisive fossa
• Begins to develop:
 Early in the 6th week
 From the internal aspect of
the maxillary processes, as
lateral palatine process

131. • In the beginning, the lateral
palatine processes project
inferomedially on each side
of the tongue
• With the development of
the jaws, the tongue moves
inferiorly.
• During 7th & 8th weeks, the
lateral palatine processes
elongate and ascend to a
horizontal position above
the tongue
Tongue

132. • Gradually the lateral palatine
processes:
 Grow medially and fuse
in the median plane
 Also fuse with the:
• Posterior part of the
primary palate
&
• The nasal septum

133. • Fusion with the nasal
septum begins anteriorly
during 9th week, extends
posteriorly and is
completed by 12th week
Bone develops in the
anterior part to form the
hard palate. The posterior
part develops as muscular
soft palate

135. DEVELOPMENT OF
LIPS

136. DEVELOPMENT OF LIPS
Lower lip :The mandibular processes of the two sides grow towards each
other and fuse in the midline ,they form the lower margin of the
stomatodeum .
Upper lip :Each maxillary process now grows medially and fuses, first with the
lateral nasal process and the with the medial nasal process.

137. • The mesodermal basis of the lateral part of the lip is formed from the maxillary
process.
• The overlying skin is derived from the ectoderm covering this process.
• The mesodermal basis of the medial part of the lip(PHILTRUM)is formed from
the frontonasal process .
• The muscles of the face (including those of the lips)are derived from the 2nd
branchial arch and are supplied by the facial nerve.

138. Anomalies Of Palate And
Lips

139. Cleft lip and palate
Classification systems
Numerous classification systems:
• Veau
• American Cleft Palate-Craniofacial Assn (ACPA)
• Kernahan and Stark
Veau’s system:
I Cleft of soft palate only
II Cleft of hard and soft palate to incisive foramen
III Complete unilateral cleft of soft and hard palate and lip
and alveolar ridge on one side
IV Complete bilateral cleft of soft and hard palate and lip and
alveolar ridge on both sides

141. Cleft lip coupled with clefts of the anterior palate or entire
palate.

142. Incidence of cleft lip and palate
• 1:750 live births
• Clefts of lip is more frequent and is more
severe in males
• Clefts of palate is more frequent in females

143. DEVELOPMENT OF
EAR

144. DEVELOPMENT OF EAR
The three parts of the ear-
-External
-Middle and
-Internal ,arise from separate ,diverse embryonic
origins .

145. The external ear forms around the first branchial groove which deepens to
become the external acuostic meatus .
Malleus and Incus are derived from the dorsal end of the first branchial arch
cartilage –MECKEL’S CARTILAGE.
Stapes arise from the dorsal end of the second branchial arch cartilage-
REICHERT’S CARTILAGE .
This is the first sensory organ to begin development .

146. DEVELOPMENT OF
EYE

147. DEVELOPMENT OF EYE
 The light sensitive portion of the eye
retina ,is the outgrowth from the
forebrain ,projecting bilaterally as the
optic vesicles which are connected to the
brain by the optic stalks, this results in a
thickening called as lens placodes.
 These placodes invaginates in it’s centre
by the development of peripheral folds .
 The optic vesicles invaginate partly to
form the double layered optic cusps and
the optic stalk becomes the optic nerve .
 The outer layer of the optic cup acquires
pigmentation to become the pigmented
layer of the retina.

148. Microcornea
Megalocornea
ANOMALIES OF EYE

149. DEVELOPMENT OF
TONGUE

150. DEVELOPMENT OF TONGUE
The tongue appears in the embryo of approximately 4 weeks in the form of
two lateral lingual swelling and one medial swelling –TUBERCULUM IMPAR
.
The three swellings orginate from the 1st pharyngeal arch.
As the 3 swellings increase in size ,they overgrow the tuberculum impar and
merge with each other thus forming the anterior two thirds or the body of the
tongue.

151.  At the junction of the anterior 2/3rd and the posterior 1/3rd is a groove
called as the SULCUS TERMINALIS.
 Sensory innervation-2/3rd - Mandibular branch of
Trigeminal nerve
 Sensory innervation-1/3rd - Glossopharyngeal nerve .
 Motor innervation Hypoglossal nerve
 Special sensory innervation - Chorda tympani branch of Facial nerve

152.  Ankyloglosia
 Bifid Tongue
 Microglossia
 Macroglossia
 Aglosia
 Fissured tongue
ANOMALIES OF TONGUE

153. That’s All About Prenatal Growth
Of Face

154.  RAY E. STEWART, THOMAS K. BARBER, KENNETH
C.TROUTMAN, STEPHEN H. Y. WEI: GENERAL CONCEPTS OF
GROWTH AND DEVELOPMENT.1982;03-43.
 P.M. SOM AND T.P. NAIDICH. ILLUSTRATED REVIEW OF THE
EMBRYOLOGY AND DEVELOPMENT OF THE FACIAL REGION,
PART1:EARLY FACE AND LATERAL NASAL CAVITIES:AMERICAN
JOURNAL OF NEURORADIOLOGY.2013;01-08.
 OLIVIER PASCALIS, XAVIER DE MARTIN DE VIVIÉS, GIZELLE
ANZURES, PAUL C. QUINN, ALAN M. SLATER, JAMES W.
TANAKA, AND KANG LEE. DEVELOPMENT OF FACE
PROCESSING:NIH PUBLIC ACCESS 2011;01-13.
 INDERBIR SINGH: HUMAN EMBRYOLOGY, 7TH EDITION.
REFERENCES