Fixed Appliance Flashcards
Define fixed appliance
Any appliance fixed to teeth and cannot be removed by pt
Components of fixed?
Bracket
Band
Arch wire
Ligature / module
Tubing
Auxiliaries
Anchorage components
When are fixed appliances used?
Correct mild to moderate skeletal discrep
Alignment of teeth
Correct rotations
Centreline correction
Overjet / overbite reduction
Space creation or closure
3D tooth movement
What are Andrew’s 6 keys?
Tight approximal contacts with no rotations
Class 1 incisors
Class 1 molars
Flat OP or small curve of spee
Long axis of teeth have slight mesial angulation except lower incisors
Crows of canines to molars have lingual inclination
Components of a bracket?
Bracket slot
Tie wings
Bracket base
What part of the bracket affects angulation of tooth?
Buccal lingual angulation = bracket base thickness / torque
Mesial / distal angulation = tip
Main materials for archwires?
SS
NiTi
Properties of NiTi wire?
Flexible
Shape memory so light continouous force
Has higher friction than SS
- want things to slide easily
What are force generating components
Sliding mechanics
- elastic power chain
- NiTi coils
- intra oral elastics
- active ligatures
Teeth move by using elastic potential energy stored within the material
How can absolute anchorage be achieved?
TADS - temporary anchorage device
- mini screw - not osseointegrated
What features have high relapse potential?
Diastema / space closure
Rotations
Palatally ectopic canines
Proclined lower incisors
AOB
In standing upper laterals
Main risks with fixed appliances
Decalcification
Root resorption
Relapse
