The document summarizes the development of the face and its structures from the 4th to 7th weeks of gestation. It describes how facial prominences like the maxillary and mandibular prominences form and contribute to structures like the upper lip, nose, and palate. It also discusses the development of the tongue from lingual swellings and how various nerves innervate parts of the developing face and tongue.

1. Development of the Face
Dr.Dashrath Kafle

2. Face
 At the end of the 4th week, facial prominences consisting
primarily of neural crest-derived mesenchyme appear
 Maxillary prominences- lateral to the stomodeum
 mandibular prominences- caudal to stomodeum
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3. Face contd...
 Frontonasal prominence - proliferation of mesenchyme
ventral to the brain vesicles
 On both sides, local thickenings of the surface ectoderm,
the nasal placodes originate
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5. Face contd...
 During the 5th week, the nasal placodes invaginate to
form nasal pits
 Lateral nasal prominences
 Medial nasal prominences
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7. Face contd...
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8. Formation of lip
 The maxillary prominences grow medially,
compressing medial nasal prominences towards
midline, two fuse forming upper lip by two medial
nasal prominences and two maxillary prominences
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10. Development of nose
 Maxillary prominences enlarge to form the cheeks and
maxilla
 Nose is formed from five facial prominences:
- frontal prominence gives rise to bridge
- merged medial nasal prominences provide the
crest and tip
- lateral nasal prominences form the alae
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11. Intermaxillary Segment
 Two medial nasal prominences merge at a deeper level
forming the intermaxillary segment
 Composed of
(a) philtrum of the upper lip
(b) upper jaw component- carries the four incisor teeth
(c) primary palate
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12. Intermaxillary Segment contd...
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13. Secondary Palate
 Formed by two palatine shelves (6th week of
development) –maxillary process
 Directed obliquely downward on each side of the tongue
 In the 7th week, the palatine shelves ascend to attain a
horizontal position above the tongue and fuse, forming the
secondary palate
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14. Secondary Palate contd...
Nasal septum: derivative of
Frontonasal process
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15. Secondary Palate contd...
 Anteriorly, the palatine shelves fuse with the primary
palate
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18. Development of Tongue
 Appear at 4 weeks
 As two lateral lingual swellings and one medial swelling,
the tuberculum impar (all originate from the first
pharyngeal arch)
 A second median swelling, the copula, formed by
mesoderm of the second, third, and part of the fourth arch
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19. Tongue contd...
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20. Tongue contd...
 Lateral lingual swellings increase in size, overgrow the
tuberculum impar and merge, forming the anterior two-
thirds, or body, of the tongue
 The body of the tongue is separated from the posterior
third by a V-shaped groove, the terminal sulcus
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22. Tongue contd...
 A third median swelling, formed by the posterior part of
the fourth arch, marks development of the epiglottis
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23. Development contd....
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24. Tongue contd...
 The mucosa covering the body of the tongue originates
from the first pharyngeal arch
 Sensory innervation to the posterior part, or root part of
the tongue is supplied by the glossopharyngeal nerve
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25. Tongue contd...
 The epiglottis and the extreme posterior part of the tongue
are innervated by the superior laryngeal nerve, reflecting
their development from the fourth arch
 Most tongue muscles are derived from myoblasts
originating in occipital somites. So innervated by the
hypoglossal nerve
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26. Tongue contd...
 Special sensory innervation (taste) to the anterior two
thirds of the tongue is provided by the chorda tympani
branch of the facial nerve, while the posterior third is
supplied by the glossopharyngeal nerve
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27. Development contd.......
•Circumvallate papilla-
- months
• Fungiform - weeks
•Filliform – after birth
•Gustatory cells- starts
th week
•All taste bud present at
birth except- taste bud
(circumvallate papilla)
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