Chapter 5: Orofacial Development

Question 1

What two structures does the palate form from?

Answer 1

primary palate and secondary palate

Question 2

When is the palate fully completed?

Answer 2

12th week of fetal period

Question 3

What are the 3 consecutive stages of palate formation

Answer 3

Formation of primary palate
Formation of secondary palate
Completion of final palate

Question 4

What are the time periods of the 3 palate stages

Answer 4

Primary palate: 5th - 6th week
Secondary Palate: 6th - 12th week
Final palate: 12th week

Question 5

What palatal structures are involved in the primary palate?

Answer 5

Intermaxillary segment from fused medial nasal processes

Question 6

What palatal structures are involved in the secondary palate?

Answer 6

Fused palatal shelves from maxillary processes

Question 7

What palatal structures are involved in the final palate?

Answer 7

Fusion of all three processes

Question 8

The final palate involves what?

Answer 8

Fusion of swellings or tissue from different surface of the embryo

Question 9

What forms during the 5th week?

Answer 9

Intermaxillary segment due to fusion of medial nasal processes

Question 10

Intermaxillary segment aka … (2)

Answer 10

Globular processes
Primary palate (gives rise)

Question 11

Premaxillary part of the maxilla is also the …

Answer 11

Anterior 1/3rd of the hard palate

Question 12

What does the anterior 1/3rd of hard palate contain?

Answer 12

Maxillary anterior teeth (incisors)

Question 13

When does secondary palate formation occur

Answer 13

During 6th week

Question 14

What happens to maxillary process in week 6

Answer 14

Gives rise to two palatal shelves

Question 15

Palatal shelves aka..

Answer 15

Lateral palatine processes

Question 16

Explain how and where palatal shelves grow and develop

Answer 16

Grows inferiorly and vertically inside the stomodeum, along sides of developing tongue

Question 17

How is the secondary palate formed

Answer 17

When 2 palatal shelves elongate, move medially towards each other and fuse

Question 18

What is the posterior 2/3rd of the hard palate consists of

Answer 18

Secondary palate
Canines and posterior teeth

Question 19

What does the secondary palate give rise to?

Answer 19

Posterior 2/3rds of hard palate, soft palate, uvula

Question 20

What is the median palatine raphe

Answer 20

Line on the palate of maxillary bone that indicates fusion of palatal shelves

Question 20

What is the median palatine raphe

Answer 20

Line on the palate of maxillary bone that indicates fusion of palatal shelves

Question 21

What happens after the final palate is formed

Answer 21

Oral cavity becomes completely separated from nasal cavity

Question 22

How does a cleft palate occur

Answer 22

failure of fusion of palatal shelves with primary palate

Question 23

What structure develops during the same time frame as the palate

Answer 23

Nasal cavity

Question 24

What week does the tongue develop

Answer 24

Week 4

Question 25

How does the tongue begin to develop

Answer 25

Begins as a triangular median swelling

Question 26

What is the tuberculum impar

Answer 26

Median tongue bud

Question 27

Median lingual sulcus

Answer 27

Superficial demarcation of line of fusion of two lateral lingual swellings

Question 28

What does the degeneration of cells around lingual swellings form?

Answer 28

A sulcus

Question 29

What does the formation of sulcus mean in the tongue development

Answer 29

Body of tongue is freed from the floor of the mouth except for a small attachement

Question 30

What is the midline lingual frenum

Answer 30

attachment in floor of mouth that attaches the tongue to the floor

Question 31

What is the copula

Answer 31

Pair of swellings Becomes posterior 1/3rd of tongue (base of tongue)

Question 32

Epiglottic swelling marks...

Answer 32

Marks the development of most posterior region of tongue and site of future epiglottis

Question 33

Sulcus terminalis

Answer 33

inverted V-shape groove on dorsal surface of tongue Marks the border between the base of tongue and its body

Question 34

Foramen cecum

Answer 34

beginning of thyroglossal duct site of development of thyroid gland

Question 35

What does the thyroglossal duct show

Answer 35

origin of thyroid gland and migration pathway of thyroid gland into the neck region

Question 36

Where does thyroid gland form

Answer 36

Inferior terminus

Question 37

What part of the tongue forms during 4th-8th weeks

Answer 37

Body: tuberculum impar and lateral lingual swellings appear Base: Copula overgrowing second branchial arches

Question 38

What part of the tongue forms during the 9th week

Answer 38

Completed tongue: merging of anterior swellings of body and copula base