Development Of Orofacial Structrues

Question 1

Facial development depends on inductive ____ between the forebrain, frontonasal region, and developing eye

Five facial primordial appear during early ____ week as prominences around the stomodeum (entrance to oral cavity)

What are they?

What separates the prominences from the cavity of primordial pharynx?

Answer 1

4th

Maxillary prominences (2)
Mandibular prominences (2)
Frontonasal prominence (1)

Oropharyngeal membrane

Question 2

When does facial development occur?

____ surrounds the ventrolateral part of the forebrain. The frontal part becomes the ____; nasal portion becomes the roster all boundary of the ____ and ____; form from ____ of the forebrain and midbrain.

Answer 2

Weeks 4-8

Question 3

J

Answer 3

J

Question 4

Lower jaw and lower lip are the first parts of the face to form. The ____ disintegrates and there is extension and fusion of _____ towards the midline.

Answer 4

Oropharyngeal membrane

Mandibular prominences

Question 5

By end of ____ week, nasal placodes form on the inferolateral part of the ____. They are oval thickening of surface ectoderm that are primordia of _____.

Answer 5

4th

Frontonasal prominence

Nasal epithelium

Question 6

Placodal edges proliferate to produce _____ and _____. The nasal placodes lie in depressions called ____ that form the nostrils anal nasal cavities. _____ forms the alae (sides) of the nose.

Answer 6

Medial and lateral nasal prominences

Nasal pits

Lateral nasal prominences

Question 7

_____ grow medially towards each other and the median nasal prominences. This results in movement of the median nasal prominence towards the midline.

Lateral nasal prominence is separated form the maxillary prominence by a cleft called ____.
Theses two prominences merge at ____ week and contribute to _____.

Answer 7

Maxillary prominence

Nasolacrimal groove

6th

Upper lip

Question 8

During ____ weeks, the medial nasal prominences merge with the maxillary and lateral nasal prominences.

They form the ____ that becomes the upper lip/philtrum, premaxillary part of maxilla, primary palate.

Answer 8

7-10

Intermaxillary segment

Question 9

Mesenchyme in PA2 forms ____ innervates by the facial N.

Mesenchyme in PA1 forms _____ innervated by trigeminal N.

Answer 9

Facial muscles

Muscles of mastication

Question 10

As face develops, nasal placodes are depressed forming ____.

Expansion of the MNP and LNP mesenchyme causes the nasal pits to deepen forming _____.

Answer 10

Nasal pits

Primordial nasal sacs

Question 11

Nasal sacs grow dorsally and ventrally to the developing forebrain. Sacs are separated from the oral cavity by _____. Ruptures end of ___ week.

Answer 11

Oronasal membrane

6th

Question 12

Palatogenesis begins ____ week and completed by _____ week.

The critical period is the end of the ___ week to beginning of ___ week.

Answer 12

6th; 12th

6th; 9th

Question 13

Merging of the MNP forms the ____. This is a wedge-shaped mass of mesenchyme between the maxillary prominences and forming the ______.

Answer 13

Median palatine process (primary palate)

Premaxillary part of the maxilla

Question 14

Secondary palate develops during early ____ week from ____.

Answer 14

6th

Lateral palatine processes (palatal shelves)

Question 15

F

Answer 15

F

Question 16

Bone gradually develops in the primary palate forming the ____, which lodges the incisor teeth.

Bone extends from maxillae and palatine bones into lateral palatine processes to form the ____.

Nasopalatine canal persists in the median plane, represented in the adult hard palate by the ____.

Answer 16

Premaxillary part of maxilla

Hard palate

Incisive fossa

Question 17

The posterior portions of the hard palate do not ossify. They extend posteriorly and fuse forming the ____ and ____.

____ is the line of fusion.

Answer 17

Soft palate and uvula

Palatine raphe

Question 18

____ extends through upper lip; clefts nose and/or maxilla

Answer 18

Cleft lip

Question 19

____ is a cleft of secondary palate to incisive fossa.

Answer 19

Cleft palate

Question 20

Nasal septum forms from down growth of the internal parts of the merged ____.

Fusion of nasal septum and palatine processes begin anteriorly during ___ week and is completed posteriorly during ____ week.

Answer 20

Median nasal prominences

9th; 12th

Question 21

_____ appears at the end of the 4th week; it is the first indication of tongue development.

Answer 21

Median lingual swelling

Question 22

J

Answer 22

J

Question 23

The pharyngeal part of the tongue are formed from the ventromedial parts of the PA2 fuse

Answer 23

N

Question 24

H

Answer 24

H

Question 25

What are three tongue abnormalities?

Answer 25

Glossoschissis (Bifid tongue)

Ankyloglossia

Macroglossia (large tongue)

Question 26

The skull is divided into two parts?

Answer 26

Neurocranium: bony case that encloses the brain

Viscerocranium: bones comprising the facial skeleton

Question 27

N

Answer 27

N

Question 28

N

Answer 28

N

Question 29

N

Answer 29

N

Question 30

Membranous viscerocranium

Answer 30

J

Question 31

Premature fusion of cranial sutures is called ___.

Scaphocephaly

Brachycephaly

Plagiocephaly

Trigonocephaly

Answer 31

Craniosynostosis

Premature closure of sagittal suture -> cranium becomes long narrow and wedge shaped

Premature closure of the coronal suture

Premature closure of the coronal suture on one side

Premature closure to the frontal suture

Question 32

Odontogeneses/ teeth development from reciprocal inductions between ____ induced mesenchyme and overlying epithelium.

Answer 32

Neural crest

Question 33

Tooth bud is invested by ____.

Consists of enamel organ, dental papilla, and dental sac.

Answer 33

Mesenchyme