Growth Theories

Question 1

All Craniofacial growth is governed by ______.
•Same as long bone growth(growth centers)
•Play a significant role in craniofacial development.
•Strong family influence.
•Difficult to isolate craniofacial growth genes as the
patterns are just too complex.

Answer 1

genetics

Question 2

T/F: The dimensions of the craniofacial complex are highly heritable. Genetics clearly plays a major role in craniofacial growth

Answer 2

True

Question 3

___ control of craniofacial development: some genes are turned off and on

Answer 3

Epigenetic

Question 4

_____ theory: Proffitt –Environmental
•Balance of forces keep the teeth and jaws in their position
•Duration of force more important than magnitude
•Based on the fact that the dentoalveolar is highly responsive to altered forces and function.

Answer 4

Equilibrium (Functional) Theory

Question 5

\_\_\_\_\_\_\_
•Epiphysis of long bones
•Responsible for growth of long bones
•Cells are layered in a precise manner
•Transplanted cell will continue to grow (chemical mediators?)
•Do  not respond to tension or pressure

Answer 5

Growth centers

Question 6

________
•Mandibular condyles, sutures, tuberosity
•Immature cartilaginous cells (not layered)
•Stop functioning if transplanted (mediators)
•Growth sites are sensitive to mechanical stimulations ( tension, pressure)

Answer 6

Growth sites

Question 7

_______: made of fibrocartilage; not well organized; respond to mechanical stimuli

Answer 7

Growth sites

Question 8

Amount of growth in a growth site is much ____ than growth center

Answer 8

Lower

Question 9

________ are genetically programmed and less affected by the environment

Answer 9

Growth centers

Question 10

Growth spurts•Female: _____ years old

Answer 10

10-12 years old

Question 11

Growth spurts•Male: _______ years old

Answer 11

12-14 years old (until 17)

Question 12

•In order to modify growth, you must first experience _____

Answer 12

growth

Question 13

______ dimension of growth:
•Favorable dentoalveolar compensations
•If no mandibular growth takes place, severe proclination of incisors may be observed.

Answer 13

A-P

Question 14

______ appliance must be worn for 12 hours per day for a year; used in a Class 3 skeletal case

Answer 14

Reverse pull head gear

Question 15

• Slows down growth at the tuberosity level
• Growth site
• Let the mandible “catch up” (anterior bite plane)
• Then resume normal growth pattern

Answer 15

Head gear

Question 16

_______ used to do multiple things and is not removable; mainly a dentoalveolar response

Answer 16

Fixed functional appliances