Development of Orofacial Structures

Question 1

FNP NCC come from where

NCC to arch 1 come from

Answer 1

forebrain and midbrain

midbrain and hindbrain

Question 2

Neurocranium vs viscerocranisum

Answer 2

neurocranisum is brain case, viscerocranium is face, jaw and larynx

Question 3

Skull

Endochondral ossification creates?

Intramembranous ossification creates?

Answer 3

red=mesoderm blue is NC

Enochondral ossification:

• neurocranium
  occipital: meso

Body of sphenoid: meso

ethmoid: NC

petrous/mastoid parts of temp: meso

-viscerocranium

ossicles of the ear NC

Intramembranous ossification flat bones

Neurocranium

parietal meso, Frontal NC

viscerocranium

squamous temporal, maxillary, zygomatic all NC

Question 4

Congenital abnormalities

Premature closure of sutures

• what is plagiocephaly?
• what isoxycephaly or brachycephaly?
• what is scaphocephaly

Answer 4

scaphocephaly elongates head in A/P direction

oxycephaly leads to prominent forehead

Question 5

Derivatives of:

• Mandibular prominence
• Maxillary prominence
• Frontonasal prominence

Answer 5

Question 6

Question 7

Characteristics of frontonasal dysplasia and embryologic mechanism of defects

Answer 7

accounted for by lack of migration or fusion of medial nasal prominence. problem w/ frontal nasal prominence or more specifically medial nasal prominences.

Question 8

Answer 8

A. problem w/ fusion of medial nasal prominence

B. mandibular prominences did not completely fuse

C. nasal lacrimal duct didnt form. both of them, maxillary prominence didnt fuse w/ intermaxillary segment, and maxillary prominence didnt fuse w/ lateral nasal prominence. facial cleft

D. maxillary and mandibular didnt fuse “enough”

E. Overfusion of maxillary and mandibular, one nostral is overfusion of medial nasal prominence

F. medial nasal prominence didn’t completely fuse

Question 9

Critical weeks for palate formation? overall weeks for palate formation?

-secondary palate gives rise to what?

is derived from what?

Answer 9

critical is 6-9

Question 10

Week 7

Answer 10

Question 11

Facial Primordia:

• how many
• when?
• separated from cavity of primordial pharynx by what? what happens to it?

Answer 11

Question 12

Facial development occurs during which weeks?

• FNP surrounds what part of the forebrain?
• FNP is from NCC of what parts of brain

Answer 12

FNP surrounds ventrolateral part of forebrain

• frontal portion will form the forehead, nasal portion forms rostral boundary of stomodeum/nose.
• FNP is NCC from forebrain and midbrain

Question 13

PA1 splits into what?

• what contributes their NCCs?
• boundaries of stomodeum?

Answer 13

Question 14

First things that form in the face

-whats happening 3rd and 4th week: what disintegrates, what extends and fuses toward midline?

Answer 14

Question 15

whats happening by end of 4th week on inferolateral parts of FNP?

• what produces MNP/LMP?
• nasal pits come from? what do nasal pits form?

Answer 15

Question 16

Formation/ Morphological changes of nasal pits

Question 17

• which way do maxillary prominences grow?
• what does the nasolacrimal groove separate?
• by end of sixth week what has merged and what has formed

Answer 17

Question 18

Between 7-10th weeks what happens to MNP, MXP, LNPs?

• results in?
• what forms the intermaxillary segment?

Answer 18

Question 19

• what structures form from maxillary prominence?
• mesoderm in PA2 forms what?
• mesoderm in PA1 forms?
• innervation of both

Answer 19

Question 20

Nasal Cavities:

• what causes nasal pits to deepen, what does this form?
• what does the oronasal membrane separate and when does it rupture?

Answer 20

Question 21

• primary chonae, secondary
• olfactory epithelium comes from

Answer 21

Question 22

Palatogenesis:

• during which weeks, which weeks critical
• what is merging
• what is primary palate

Answer 22

Question 23

• what is the definitive palate?
• when does secondary palate develop and from what?
• palatal shelves and importance of tongue movement
• when do palatal shelves become horizontal

Answer 23

Question 24

Final palate:

• what forms the premaxillary part of maxilla
• what forms hard palate
• soft palate formed by
• Nasopalatine canal persists as what in adult

Answer 24

Question 25

Cleft palate vs cleft lip

Answer 25

Question 26

Question 27

Nasal Septum: - down growth of what - fusion begins when and in what direction, ends?

Answer 27

Question 28

Tongue development: - Median lingual swelling when? - lateral lingual swellings comprise what parts of tongue - where do tongue buds come from?

Answer 28

Tongue Development  Median lingual swelling (median tongue bud) appears at the end of 4th week o 1st indication of tongue development o Triangular elevation in floor of primordial pharynx  Two lateral lingual swellings (distal tongue buds) develop on each side of the median lingual swelling  All tongue buds result from proliferation of mesenchyme in ventromedial parts of PA1  Merged lateral lingual swellings form the oral part, anterior 2/3 of the tongue o Rapidly proliferate, merge, & overgrow median lingual swelling

Question 29

Tongue development: - pharyngeal part of tongue - what forms copula - what forms hypopharyngeal eminence - what forms posterior 1/3 of tongue - musculature derived from? - innervation?

Answer 29

Question 30

tongue abnormalities:  Glossoschissis (bifid tongue)  Ankyloglossia  Macroglossia

Answer 30

ankyloglossia is tongue tied frenulum overgrown

Question 31

Types of ossification:

Answer 31

Question 32

Neurocranium vs viscerocranium:

Answer 32

Question 33

Nerve supply to tongue: anterior 2/3 vs posterior 1/3

Answer 33

Question 34

Neurocranium: cartilaginous parts? and type of ossification membranous parts? and type of ossification

Answer 34

Question 35

Viscerocranium: Cartilaginous portion: NCCs form?, contribution from PA1 PA2 PA3 PA4 membranous portion: what happens to squamous temporal bones

Answer 35

Question 36

Craniosynostosis: - Scaphocephaly - brachycephaly - plagiocephaly - trigonocephaly

Answer 36

Question 37

Odontogenesis: - teeth develop from reciprocal inductions between what tissue populations? - Dental laminae - Tooth buds how many? - which direction do they form and what week

Answer 37

Question 38

Cap stage: - bud is invested by what? - cap structures - what tissue is enamel organ, outer vs inner enamel - what is stellate reticulum - what is dental papilla - dental follicle sac: what is it, and what does it eventually form

Answer 38

Question 39

Bell stage: - what is happening - what forms odontoblasts and what do they produce - inner enamel epithelium differentiates into what? produces what? - progression of enamel and dentin formation

Answer 39

Question 40

Root attachment: - begins when? - what is epithelial root sheath? - what forms pulp? - what forms cementoblasts? - what forms the periodontal ligament?

Answer 40

Question 41

Tooth eruption: - what happens to the deciduous root? - when do permanent teeth come?

Answer 41

Question 42

Permanent tooth formation - how many - when do permanent tooth buds appear

Answer 42