Face, jaws, mouth: part 1

Question 1

describe fronto-nasal process

Answer 1

prominence in the upper facial area at the most cephalic end of the embryo

Question 2

describe cephalic end

Answer 2

head end of a structure such as the trilaminar embryonic disc

Question 3

describe mandibular processes

Answer 3

process of first branchial arch that fuse at the midline to form mandibular arch

Question 4

describe maxillary processes

Answer 4

prominence from mandibular arch that grows superiorly and anteriorly on each side of the stomodeum of the embryo

Question 5

describe nasal placode

Answer 5

placodes that develop into olfactory organ for the sensation of smell located in the mature nose

Question 6

describe placode

Answer 6

area of ectoderm found at the location of the developing special sense organs on the embryo

Question 7

how is the basic morphology of the face established?

Answer 7

• between the fourth and tenth week
• by the development and joining of the five prominences

Question 8

Answer 8

These lower processes surround the stomodeium or the primitive oral cavity

The stomodeum is separated from the gastro intestinal tract by an oropharyngeal membrane and during the 5th week as the paired maxillary prominences grow and enlarging grow ventrally and medially what will happen is that we will start to disintegrate

Question 9

describe stomodeum

Answer 9

• First part of process when the temporary membrane disintegrates
• Common oro-nasopharyngeal chamber
• Primary palate:
• from the fused medial nasal prominence (intermaxillary segment)
• does NOT separate oral and nasal cavities - demarcates

Question 10

describe the formation of the face

Answer 10

4th week:
- primitive stomodeum bounded by
- FNP, max. and mandibular process
- nasal placodes, develop into nasal pits

5th week:
- nasal pit surrounded by lateral + medial nasal prominence

6th+7th week:
- medial nasal prominences fuse together and fuse with maxillary processes

Question 11

describe ossification-bone formation

Answer 11

• 6-7 week - mandible
• 8th week - maxilla
• 8th week - palate and nasal capsule
• week 8 we get the primary palate

Question 12

describe bone development

Answer 12

2 methods of osteogenesis:
- intramembranous
- Endochondral
- Indistinguishable in mature bone
- bone formed by these two ways is microscopically the same

Question 13

what are the five growth factors families implicated in the facial development?

Answer 13

BMP, FGF, Shh, Wnt and endothelins

control proliferation, survival and apoptosis

Question 14

Answer 14

Question 15

Answer 15

Question 16

Answer 16

Question 17

Answer 17

Question 18

Answer 18

Question 19

Answer 19

Question 20

Answer 20

Question 21

Answer 21

Question 22

Answer 22

Question 23

Answer 23

Question 24

Answer 24

Question 25

There are 2 types of fusion

Answer 25

Fusion - proliferation of cells in a furrow to fuse together 2 prominences (between medial nasal prominences for example)
True fusion - Between 2 separate

Question 26

How is the face formed?

Answer 26

By the fusion of 5 prominences by ectomesenchyme migration caused by differentiation

Question 27

What are the first signs of tooth development?

Answer 27

at 6 weeks with the formation of a primary epithelial band which will form a tooth bud

Question 28

where is the primary ossification centre?

Answer 28

Located at the termination of the infra-orbital nerve (just superior to the dental lamina of the primary maxillary canine tooth in each maxillary process)

Question 29

Where is the mandibular/secondary ossification centre?

Answer 29

Located at the zygomatic, orbital-nasal, nasal-palatine and inter-maxillary, and appear and fire rapidly. The inter-maxillary ossification centres generate the alveolar ridge and the primary palate region.

Question 30

What is CCN2?

Answer 30

Is a connective tissue growth factor for Meckel’s.

It’s involved in the proper development of the orofacial region, mandibular morphogenesis, and tooth development and for promoting physiological and pathological tissue remodelling (fibrotic reconstruction of tissue) throughout life, including periodontal fibrosis after periodontal disease.