Biology of Tooth Movement

Question 1

light force vs heavy force

Answer 1

Light force = <100g, causes frontal/direct resorption, preferred because movement is steady and pt experiences less discomfort

Heavy force = >100g, causes undermining/indirect resorption, not steady, lag period of 1-2 weeks

Question 2

time threshold for tooth movement, associated with the amount of time required for cAMP to reach a level to trigger an inflammatory response in the PDL

Answer 2

4-8 hours

Question 3

natural process that occurs for the force to decrease/tire out an orthodontic appliance

Answer 3

force decay

Question 4

3 forms of force decay:

Answer 4

Continuous- force is relatively constant, ex: light wires, force declines slightly over time but replacement will restore the force

Interrupted- force slowly decreases to zero, ex: elastic chains

Intermittent- force abruptly ceases, ex: clear aligners

Question 5

Name the type of tooth movement:
- crown and root move in the same direction
- ideal force = 100g
- load is applied to entire area of the PDL (equally distributed compression on one side of the root

Answer 5

bodily movement

Question 6

Name the type of tooth movement:
- crown and root forced in opposite directions
- ideal force = 50 g
- 50% of force is loaded on one side of the tooth, 50% on the other side
- most pressure at the crest of alveolar bone and root apex

Answer 6

uncontrolled tipping

Question 7

Name the type of tooth movement:
- tooth partially tipped and partially translated
- root apex does not tip as much as controlled tipping
- ideal force = 75g
- 75% of force is loaded on one side of the tooth, 25% on the other side

Answer 7

controlled tipping

Question 8

Name the type of tooth movement:
- tooth being pulled out of its socket
- ideal force = 50g
- 50% of PDL being loaded on any given side
- irregularity of root shape causes compression in areas similar to tipping forces

Answer 8

extrusion

Question 9

Name the type of tooth movement:
- tooth being pushed into its socket
- ideal force = 10g
- 10% of PDL compressed
- successful intrusion requires very light force along long axis of tooth

Answer 9

intrusion

Question 10

Name the type of tooth movement:
- root moves in direction of force, but crown barely moves
- ideal uprighting force = 75g
- 75% of PDL is being loaded

Answer 10

root torque

Question 11

Name the type of tooth movement:
- tooth rotation along its long axis
- ideal force = 50g
- 50% of PDL being loaded on any given side
- irregularity of root shape causes compression in areas similar to tipping forces

Answer 11

rotation

Question 12

method used to speed up tooth movement by utilizing the inflammatory response

Answer 12

regional accelerated phenomenon