Development of Face and Palate

Question 1

When does development of the face occur

Answer 1

4-8 weeks IUL

Question 2

When does formation of the palate occur

Answer 2

6-8 weeks IUL

Question 3

When is the earliest bone laid down in the skull

Answer 3

6-7 weeks in mandible

Question 4

What forms from the first pharyngeal arch

Answer 4

trigeminal nerve
muscles of mastication 
malleus 
incus
meckel's cartilage
(mandible and part of maxilla)

Question 5

What is Meckel’s cartilage

Answer 5

mandible forms around it

ear forms from it

Question 6

What are the pharyngeal arches

Answer 6

consist of a mesenchymal core covered on the outside by ectoderm and separated by a series of clefts and inside they are covered by endoderm and are separated by pouches

Question 7

What does each pharyngeal arch contain

Answer 7

a central rod of a precartilaignous mesenchyme which will be tranformed into some of the adult skeletal structures

Question 8

What are the 5 prominences in the face

Answer 8

frontonasal prominence
medial nasal prominence
lateral nasal prominence 
maxillary prominence
mandibular prominence

Question 9

What does the frontonasal prominence form

Answer 9

forehead

bridge of nose

Question 10

What does the medial nasal prominence form

Answer 10

inter maxillary process which forms:
midline of the nose
philtrum upper lip
primary palate

Question 11

What does the lateral nasal prominence form

Answer 11

alas of nose

Question 12

What does the maxillary prominence form

Answer 12

cheeks; lateral upper lip

Question 13

What does the mandibular prominence form

Answer 13

lower lip and jaw

Question 14

If the mandibular processes don’t fuse what does this result in

Answer 14

a cleft chin or dimple in the chin (if partially fused)

Question 15

Where the maxillary and mandibular processes fuse what will this result in

Answer 15

the corner of the mouth

Question 16

What is the stomadeuom

Answer 16

the primitive mouth

Question 17

Does the frontonasal come from the first pharyngeal arch

Answer 17

no

Question 18

How are the nasal and oral cavities separated

Answer 18

they are separated into individual cavities during the 7th and 8th week by formation of the palatal shelves

Question 19

What do the palatal shelves derive from

Answer 19

maxillary prominence

Question 20

When the palatal shelves form what does this result in

Answer 20

the secondary palate

Question 21

Where do the primary shelves fuse at

Answer 21

the incisive foramen

Question 22

What age do we have all the deciduous dentition

Answer 22

2

Question 23

From what age do we have a mixed dentition

Answer 23

6

Question 24

From what age do we have all the permanent dentition

Answer 24

12

Question 25

What can help you determine age

Answer 25

look at FPM
look for primary dentition 
look for permanent dentition
look for third molars
look for closed/open apices

Question 26

What is synchondrosis

Answer 26

Primary cartilaginous joint - mainly found in the developing skeleton

Question 27

What is an ossification centre

Answer 27

Starting point for growth

Question 28

What is the first ossification centre to appear

Answer 28

the primary ossification centre

Question 29

What is a fontanelle

Answer 29

Membranous area (‘soft spots’) between bones of the neurocranium

Question 30

What is the function of a fontanelle

Answer 30

Allows for compression and overlap of bones during birthing

Question 31

How many fontanelles are there

Answer 31

1 anterior- closes around 2 years
1 posterior - closes around 1-3 months
2 mastoid (posterolateral) - closes around 6-18 months
2 sphenoid (anterolateral) - closes around 6 months

Question 32

What can be seen in a fetal skull

Answer 32

metric suture

mental symphysis

Question 33

What is the angle of the mandible in fetal skulls and females

Answer 33

obtuse

Question 34

What is the tympanic ring

Answer 34

forms the ear

it is a ring rather than a plate in fetus

Question 35

What does the 2nd pharyngeal arch form

Answer 35

facial nerve
muscles of facial expression
hyoid

Question 36

What does the 3rd pharyngeal arch form

Answer 36

glossopharyngeal nerve
stylopharyngess
common carotid artery
hyoid

Question 37

What does the 4th and 6th arch form

Answer 37

vagus nerve
muscles of the pharynx and larynx
aortic arch
laryngeal cartilages

Question 38

What is a cleft palate due to

Answer 38

failure of the fusion of the palatal shelves at the midline

Question 39

What is a cleft lip due to

Answer 39

failure of fusion of maxillary prominence and medial nasal process