Embryology part 2

6. Organ, tissue, another
type of cells
At
certain
time &
place
Influenced
Influencer

7. Development of oral and extra oral structures:
1-development of the early face
2-development of the palate
3-development of the tongue
4-development of the oral vestibule
& alveolingual groove
5-development of the salivary glands
6-development of the mandible & maxilla
7- development of the teeth

11. Five Building blocks (primordia)
◦The frontonasal process (prominence)
Cranial to the oral pit (stomodeum).
◦Two maxillary processes (prominences)
Bilateral to the oral pit, extend from dorsal
end of 1st branchial arc .
◦Two mandibular process (prominences)
Bilateral to the oral pit, extend from ventral
end of 1st branchial arc

12. ◦Mesodermal enlargements separated by
grooves or furrows.
◦Union occur by merging rather than Fusion.
◦Merging :
Filling or smoothing of a
groove or furrow by
mesenchymal proliferation
underneath the groove.

13. ◦Fusion :
Union of 2 completely separate
mesenchymal masses each covered by
epithelium. Degeneration of intervening
epithelium must occur before
mesenchymal tissue proliferate and
complete fusion.

15. Mandibular processes grow toward each other and
merge together at their
medial end to give

24. Before it disappears
proliferate
then and forms
.

26. • Lateral sides and the
ala of the nose
• With maxillary process
(separated by lateral labial
g. or Nasal fin)
• 1) tip & center of the nose.
• 2) Inward growth  nasal
septum
• With each other 
Intermaxillary segment
• Philtrum
• Primary palate
• premaxilla

27. Lateral parts of the
upper lip
Most of the Maxilla &
associated cheek
2ry palate (lateral
palatine processes)
Forehead
Apex and dorsum of
the nose
Lower lip.
Mandible mesoderm.
Body of the tongue.
Check (Lower part)

29. 2/3 from Rt &
Lt maxillary
process
1/3 from
Intermaxillary
segment
fusion
The
upper
lip
Failure in fusion result in uni, or bilateral cleft lip.

31. maxillary
process
Mandibular
process
The
mouth
orifice
Failure in fusion result in lateral facial cleft.
Macro and microsomia

35. The tissue that separate ( ) the oral and nasal cavities

36. Small part lying anterior to the
incisive fossa of hard palate.
Posterior to the incisive
fossa of hard palate.

37. merging of
the 2 Medial
Nasal
Processes
proliferation of
mesenchyme to
fill the groove
between the
processes.
1ry palate
Premaxilla
6wiul
maxillary
processes two
lateral palatine
processes
8½ wiul, lateral
palatine processes
elevate over the
tongue (shelf
elevation).
2ry palate
7-9 wiul

42. Palatal
shelves
elevation
tongue
displacement by
the growth of
the mandible
presence of contractile
force of the fibroblasts
in the palatal processes
(myofibroblast). High mucopolysacharides
content of the shelves
which attract water
makes the shelves more
turgid.

53. Line of fusion () 2 halves of the
anterior two thirds
v-shape sulcus () the body and base,
covered by mucous over the muscles.
At the apex of sulcus terminals

54. develops from two growth centers lateral lingual
swellings and tuberculum impar. [1st branchial arch].
The lateral lingual swellings rapidly
enlarge backward to cover tuberculum
impar and forward & medially to merge
with each other to form the mucous
membrane of the anterior 2/3
: V nerve

55. The line of union between the two lateral lingual swellings
is induced externally by median sulcus and internally by
median raphae

56. Develops from the copula from[2nd branchial arches] and the 2 hypobranchial eminence
from [3rd and 4th branchial arches] posterior to the copula.
the2 hypobranchial eminence rapidly overgrows the copula which disappears.
The hypobarnchial eminence gives the mucosa covering the posterior one third.
Innervation: IX cranial nerve

59. The posterior one third become fused with the
anterior two thirds of the tongue, the site of fusion
is marked by the V shaped sulcus terminalis.
Foramen cecum  pit  invaginated
Thyroid descend through the thyroglossal duct (will
disappear) to reach the final position at 7wIUL
If persist: Thyroglossal cyst

61. .

64. Anterior 2/3
•Lingual nerve branch of mandibular
nerve which is branch of trigeminal
nerve for general sensation
. Chorda tympani branch of the facial
nerve for taste sensation

65. Posterior 1/3
Is innervated by glossopharyngeal nerve ( IX cranial
nerve ) for general and taste sensation
Internal laryngeal (branch of vagus)
Hypoglossal nerve supplies the muscle (motor nerve).

68. tongue

70. Derivation of the 1st arch (mandibular arch)
Mandible and maxilla
lower lip and part of upper lip and cheek
All the teeth
All the salivary glands
All the muscle of mastication
Anterior 2/3 of the tongue.
Remnants of Meckel’s cartilage (incus and malleus, lingula,
sphenomandibular, sphenomalleolar ligaments and mental
ossicles).