Anchorage Flashcards
1
Q
Define Anchorage?
A
- Resistance to unwanted tooth movement
- Resistance of forces generated in reaction to the active component of appliance
- Newton’s Third law of motion - Every action there is an equal and opposites
2
Q
Principle of Anchorage
A
- Increased roots of tooth increased resistance to tooth movements increased Anchorage value .
- no relation to surface of tooth.
-PDL involved
- always consider 3 dimension: AP , lateral , vertical
3
Q
Loss of Anchorage
A
- Unwanted tooth movement and space loss.
E.g . Mesial movement of Upper first Permanent molar during premolar extraction space closure
4
Q
Anchorage loss and Anchorage Burn
A
- Anchorage loss - Unintentional movement of anchor unit
- Anchorage burn - intentional movement of anchor unit
5
Q
Space management.
A
- Maximise wanted tooth movement
- minimise unwanted tooth movement
6
Q
Types of Anchorage
Intra oral
A
- Simple Anchorage
- Compound Anchorage
- Stationary anchorage
- Reciprocal anchorage
7
Q
Simple Anchorage
A
- 1 tooth against another 1-1
8
Q
Compound anchorage
A
- More than 1 tooth in anchor unit
1- Intra maxillary - same arch.-bonding 7s’
2- Inter maxillary- Opposite arches ( class 2-3 elastics traction )
9
Q
Reciprocal anchorage
A
- Equal tooth movement towards each other.
- e.g powerchain to close midline diastema
10
Q
Stationary Anchorage
A
- Resistance to bodily movement
- force tends to displace Anchorage unit bodily in the plane of space in which force is being applied
-e.g Tads
11
Q
soft tissue / Bone
A
- Soft tissue - lip bumper
-Bone - Nance button , palatal vault in URA.
-
12
Q
Why mandibular teeth have greater anchorage value than maxillary teeth?
A
- Cortical plates provide increased resistance of tooth movement than cancellous bone.
- Mandibular teeth have greater anchorage value than maxilla teeth.
13
Q
Extra oral Anchorage
A
- Anchorage from cranial vault/ basal bones
- Protraction headgear ( reverse headgear)
- Extra oral anchorage
14
Q
How can you increase Anchorage?
A
- Band all molars
15
Q
Factor affecting anchorage
A
- Type of tooth movement
- Root surface area
- Sk pattern
- Occlusal interdigitation
- Tendency for tooth movement in the arch.
Maxillary teeth have greater tendency for mesial drift.