Lecture 3

Question 1

When is extraction of an ankylosed primary tooth recommended?

Answer 1

-If the primary tooth drops below the height of contour

Question 2

T/F Growth is controlled both by genetic factors and environmental factors

Answer 2

True

Question 3

What is the theory of genetic blue print model?

Answer 3

-The role of genetic preprogramming has long been presumed by many to have a fundamental influence in establishing basic facial pattern

Question 4

How do bioelectric signals occur?

Answer 4

-From distortions of the crystals in the bone that can lead to the triggering of osteoblastic and osteoclastic responses

Question 5

What is Wolffs law?

Answer 5

-Bone in a healthy person or animal will adapt to the loads under which it is placed, if loading on a particular bone increases, the bone will remodel itself over time to become stronger

Question 6

What is the mechanostat theory?

Answer 6

-Bone growth and loss is stimulated by the local mechanical elastic deformation of bone

Question 7

There is a linear relationship in a healthy body for the growth of bone between what?

Answer 7

-Muscle cross sectional area and bone cross sectional area

Question 8

What is a growth site?

Answer 8

-A location at which growth occurs

Question 9

What is a growth center?

Answer 9

-Location at which independent growth occurs regardless of the growth and development of adjacent structures

Question 10

T/F The pressure created by growth at the sutures, causes the maxilla to be pushed downward and forward

Answer 10

False

-People used to think this was true but later discovered it was not true

Question 11

If a piece of epiphyseal plate is transplanted somewhere else and it keeps growing does that make it a growth site or growth center?

Answer 11

-Growth center

Question 12

Are sutures growth sites or growth centers?

Answer 12

-Growth sites

Question 13

Synchondroses are growth centers or growth sites?

Answer 13

-Growth centers

Question 14

Is the nasal septum a growth site or growth center?

Answer 14

-Growth center

Question 15

What does growth typically refer to?

Answer 15

-increase in size, but it can tend to be more linked to change than anything else

Question 16

T/F All of the tissue systems of the body grow at the same rate

Answer 16

False

-They do not grow at the same rate

Question 17

What does a change in growth pattern indicate?

Answer 17

-Some alteration in the expected changes in body proportions

Question 18

When is the peak growth for girls?

Answer 18

-Around 12`

Question 19

When is the peak growth for boys?

Answer 19

-Around 14

Question 20

T/F Boys will generally start growth sooner for a shorter amount of time?

Answer 20

• False

- Girls

Question 21

What are the three cellular possibilities for growth?

Answer 21

• Hypertrophy
• Hyperplasia
• Cells secrete extracellular material

Question 22

T/F Cartilage behaves like soft tissue

Answer 22

True

Question 23

THe direct addition of new bone to the bones surface can and does occur through the activity of cells located where?

Answer 23

-Periosteum

Question 24

T/F Bone is formed as a primary tissue

Answer 24

False

-It is never formed as a primary tissue

Question 25

T/F Once bone is mineralized interstitial growth is impossible

Answer 25

True

Question 26

The greatest period of cranial growth occurs between what age?

Answer 26

-Birth and 5 yrs

Question 27

What serves as a major site of bone expansion during postnatal craniofacial growth?

Answer 27

-Sutures

Question 28

For sutures to function as growth sites they need to remain in what state?

Answer 28

-An unossified state

Question 29

What type of bones is the cranial vault made up of?

Answer 29

-Flat bones formed via intramembranous bone formation

Question 30

What is the most complex structure of the human skeleton?

Answer 30

-Cranial base

Question 31

What is the first region of the skull to reach adult size?

Answer 31

-Cranial base

Question 32

How does the cranial base form?

Answer 32

-Endochondral ossification

Question 33

What are the three pairs of cartilaginous precursors for the chondrocranium?

Answer 33

• Ethmoid prechordal
• Sphenoid hypophyseal
• Occipital parachordal

Question 34

Histologically what do synchondroses look like?

Answer 34

-Two-sided epiphyseal plate

Question 35

T/F Typically more bone deposition occurs on the ethmoid bone at the sphenoethmoidal synchondrosis

Answer 35

True

Question 36

How does growth of the maxilla occur?

Answer 36

-Apposition of bone at the sutures by they periosteum

Question 37

What direction does the maxilla grow?

Answer 37

-Downward and forward

Question 38

What two ways accomplish the downward and forward growth of the maxilla?

Answer 38

• A push from behind created by cranial base growth

- By compensatory growth at the sutures in response to the displacement of the maxilla through soft tissue growth

Question 39

Where is the maxilla attached?

Answer 39

-Anterior end of the cranial base