Ortho Lab

Question 1

What is the mnemonic for removable appliance design?

Answer 1

Active component
Retentive
Anchorage
Baseplate

Question 2

What is the active component?

Answer 2

The name of the component or components that will be moving teeth with the application of force

Question 3

What is the retentive component?

Answer 3

The resistance to displacement forces

Question 4

What is anchorage?

Answer 4

The resistance to unwanted tooth movement

Question 5

What is the baseplate?

Answer 5

Connects all the components together as a unit, provides anchorage and assists with retention

Question 6

How do teeth move?

Answer 6

Prolonged force creates pressure which causes the bone around the tooth to remodel
The remodelling of bone is controlled by the PDL

Question 7

What is the composition of stainless steel?

Answer 7

72% iron
18% chromium
8% nickel
1.7% titanium
0.3% carbon

Question 8

What are the advantages of removable appliances?

Answer 8

Tipping of teeth
Excellent anchorage
Cheaper than fixed
OH easier to maintain
Can achieve block movements

Question 9

What are the disadvantages of removable appliances?

Answer 9

Less precise control of tooth movement
Can be easily removed by patient
Generally only 1-2 teeth can be moved at one time
Rotations very difficult to correct