C.1 : Cranofacial Development

Question 1

Principal neural crest-derived tissues of the head and neck

Answer 1

Neural crest-derived tissues include sensory ganglia of cranial nerves V, VII, IX, and X, branchial arch cartilages, bones of the maxilla, mandible, palate, face, and crania, chondrocranial cartilages, otic capsule, cranial vascular tissue, dermal smooth muscles, connective tissue components of cranial and lingual muscles, adenohypophysis, salivary, thyroid and parathyroid glands, thymus, melanocytes, melanophores, odontoblasts, pulpal cells, calcitonin-producing cells of ultimobranchial body, and carotid type-1 cells.

Question 2

Principal stages of craniofacial embryology

Answer 2

Stages include germ layer formation, neural tube formation, organ system formation, primary and secondary palate formation, and final tissue differentiation.

Question 3

What is the primitive mouth cavity called?

Answer 3

The storatodeum

Primitive mouth cavity

Question 4

What separates the stomatodeum from the foregut?

Answer 4

The buccopharyngeal membrane

Separation from the foregut

Question 5

What does Rathke’s pouch transform into?

Answer 5

The anterior lobe of the pituitary

Transformation of Rathke’s pouch

Question 6

When does the face develop?

Answer 6

Between the 24th and 38th days

Face development timeline

Question 7

What is the predominant feature during the fourth and fifth developmental stages?

Answer 7

Morphogenesis of the neural crest-derived facial prominences

Predominant feature in fourth and fifth stages

Question 8

Frontonasal

Answer 8

Forehead, bridge of nose, medial and lateral nasal prominences

Table 1.3 Embryonic contributions to craniofacial form

Question 9

Maxillary

Answer 9

Cheeks, lateral portion of upper lip…

Table 1.3 Embryonic contributions to craniofacial form

Question 10

Medial nasal

Answer 10

Philtrum of upper lip, crest and tip of nose

Table 1.3 Embryonic contributions to craniofacial form

Question 11

Lateral nasal

Answer 11

Alae of nose

Table 1.3 Embryonic contributions to craniofacial form

Question 12

Mandibular

Answer 12

Lower lip

Table 1.3 Embryonic contributions to craniofacial form

Question 13

When does calvarial (neurocranial) development begin?

Answer 13

Calvarial (neurocranial) development begins at the seventh to eighth week of gestation, with the unique aggregation of collagen fibers in the dura mater that preconfigure future sutures and fontanelles in the mesodermal tissues around the developing brain.

Question 14

What serves to facilitate molding of the relatively large neurocranium at parturition?

Answer 14

Separation of these flat cranial bones at birth by sutures and fontanelles principally serves to facilitate molding of the relatively large neurocranium at parturition.

Question 15

What is a major mechanism for calvarial growth?

Answer 15

Despite their small size, intramembranous osteogenesis at sutures is a major mechanism for calvarial growth.

Question 16

What changes in size and contour are achieved by on the inner and outer surfaces of the calvarial bones?

Answer 16

Changes in size and contour are achieved by differential resorption and apposition on the inner and outer surfaces of the calvarial bones.

Question 17

What serves different functions in the calvarium?

Answer 17

The calvarium incorporates squamous parts of complex bones that serve different functions and follow distinct growth patterns.

Question 18

What are the bones of the cranial base initially formed in?

Answer 18

The bones of the cranial base are initially formed in cartilage (the chondrocranium) on the ventral surface of the brain.

Question 19

What contributes significantly to skull growth by persisting until late adolescence?

Answer 19

The intersphenoidal and spheno-occipital synchondroses contribute significantly to skull growth by persisting until late adolescence.

Question 20

What impact does the length and growth of the cranial base have on craniofacial development?

Answer 20

The length and growth of the cranial base has an important impact on craniofacial development, affecting the articulation of the upper facial skeleton and the mandible.

Question 21

When does calvarial (neurocranial) development begin?

Answer 21

Calvarial (neurocranial) development begins at the seventh to eighth week of gestation, with the unique aggregation of collagen fibers in the dura mater that preconfigure future sutures and fontanelles in the mesodermal tissues around the developing brain.

Question 22

What serves to facilitate molding of the relatively large neurocranium at parturition?

Answer 22

Separation of these flat cranial bones at birth by sutures and fontanelles principally serves to facilitate molding of the relatively large neurocranium at parturition.

Question 23

What is a major mechanism for calvarial growth?

Answer 23

Despite their small size, intramembranous osteogenesis at sutures is a major mechanism for calvarial growth.

Question 24

What changes in size and contour are achieved by on the inner and outer surfaces of the calvarial bones?

Answer 24

Changes in size and contour are achieved by differential resorption and apposition on the inner and outer surfaces of the calvarial bones.

Question 25

What serves different functions in the calvarium?

Answer 25

The calvarium incorporates squamous parts of complex bones that serve different functions and follow distinct growth patterns.

Question 26

What are the bones of the cranial base initially formed in?

Answer 26

The bones of the cranial base are initially formed in cartilage (the chondrocranium) on the ventral surface of the brain.

Question 27

What contributes significantly to skull growth by persisting until late adolescence?

Answer 27

The intersphenoidal and spheno-occipital synchondroses contribute significantly to skull growth by persisting until late adolescence.

Question 28

What impact does the length and growth of the cranial base have on craniofacial development?

Answer 28

The length and growth of the cranial base has an important impact on craniofacial development, affecting the articulation of the upper facial skeleton and the mandible.