Anchorage Flashcards
What factors affect anchorage?
- number of teeth to be moved
- distance to move teeth
- type of tooth movement
- root surface area
- skeletal pattern
- occlusal intercuspation
- tendency for tooth movement in the arch
What is the definition of anchorage?
The resistance to unwanted tooth movement
How can anchorage be supplemented?
- extraction decisions
- bond the second molars
- lingual arch
- transpalatal arch +/- nance button
- intermaxillary elastics
- fixed class II traction
- functional appliance
- removable appliance - baseplate, palatal coverage
- implants - restorative, TAD, mini screws
How can anchorage strains be reduced?
- tip rather than bodily movements
- light forces
- decrease friction - self ligating brackets
- separate retraction on individual teeth
- push rather than pull
- correct the centre line one tooth at a time
What are the sources of anchorage?
- simple
- compound (intra or intermaxillary)
- stationary
- reciprocal
How does a TPA assist with anchorage?
Maintains the inter molar width
What factors affect anchorage?
- number of teeth to be moved
- distance to move the teeth
- type of tooth movement - bodily needs more
- root surface area of anchor teeth
- skeletal pattern - increased vertical height are more at risk of anchorage loss
- occlusal intercuspation
- tendency for tooth movement
How can anchorage loss sometimes be useful?
Burning anchorage - when the overjet is average but there are still spaces present
What is simple anchorage?
One tooth against another
What is stationary anchorage?
Use of TADS, implants, ankylosed teeth
What is reciprocal anchorage?
Equal forces applied to equal teeth which causes equal movement towards each other - for example using powerchain on a midline diastema
What is compound anchorage?
More than one tooth in an anchor unit
Intra maxillary - same arch
Inter maxillary - opposing arches - class II / III traction
What are reasons for anchorage loss?
- forces too heavy
- maxillary arch is more susceptible
- occlusal interferences
- vertical growth pattern
- poor patient compliance - not wearing ura/headgear/elastics, fixed appliances with lots of breakages
How can anchorage be reinforced?
- increase teeth in anchor unit
- making movement of anchor teeth more difficult
- intermaxillary elastics
- palatal/lingual arches
What dimensions should be considered with anchorage?
All dimensions - AP, lateral and vertical
