Fixed Orthodontics Flashcards
What is the definition of a fixed appliance?
An appliance which is fixed to the teeth and cannot be removed by the patient
Consists of brackets, bands, archwires and auxillaries
When to use fixed appliances?
Correction of mild to moderate skeletal discrepancy (camouflage)
Alignment of teeth
Correction of rotations
Centreline correction
Overbite and overjet reduction
Closure of spaces/creating space
Vertical movements of teeth
What are the Andrews Six Keys of orthodontic treatment?
- Tight approximal contacts with no rotations
- Class I incisors
- Class I molars
- Flat occlusal plane or slight curve of Spee
- Long axis of the teeth have a slight mesial inclination except the lower incisors
- The crowns of the canines back to the molars have a lingual inclination
What different materials are used for orthodontic archwire?
Stainless steel
Nickel titanium
Cobalt chromium
Beta-titanium
Compoiste/glaa
What are the properties of nickel titanium that enable its use for archwires?
Flexible
Light continuous force
Shape memory
–return to original shape
–cannot bend
Higher friction than stainless steel
What are the properties of stainless steel that enable its use for ortho archwire?
Working archwires to slide teeth (low friction)
Formable (archwire bends)
What sliding force generating components can be used?
How do these work?
Elastic power chain
NiTi coils
Intra-oral elastics
Active ligature
TEETH MOVE BY UTILISING THE ENERGY STORED IN THE ELASTIC OR SPRING
What is anchorage?
Resistance to unwanted tooth movement
What is Newton’s 3rd law?
Every force has an equal but opposite reactionary force
What is a TAD?
Where can they be placed?
Temporary anchorage device
–non-osseointegrating mini screw
Inter-radicular TAD, Palatal TAD
What can provide cortical anchorage?
Cortical plates provide increased resistance to tooth movement
Maintains intermolar width
What features of a malocclusion have high relapse potential?
Diastema/space closure
Rotations
Palatally ectopic canines
Proclination of lower incisors
Anterior open bite
Instanding upper lateral incisors
What is retention in regards to orthodontic treatment?
Maintaining the final tooth position with a passive orthodontic appliance
In what situations would you place a permanent retainer? (lingual/palatal retainer)
Space closure
Diastema
Proclination of lower labial segment
Periodontal cases
Ectopic canines
Instanding upper 2’s
Name the 3 main risks of orthodontic treatment.
Decalcification
Root resorption
Relapse
