Anchorage Flashcards
What is anchorage?
Resistance to unwanted reciprocal tooth movements
What is the rate of tooth movement related to? And what is this theory called?
Differential theory stages that: level force per unit root area over a certain range of force
What are the sources of intraoral anchorage?
root surface area teeth in same arch palate opposing teeth implants/TAD
What is EO anchorage and What are sources of E/O anchorage?
This is when the force to move the teeth is from the outside head gear attaching onto cranial bones
What is loss of anchorage?
movement of the anchor teeth during orthodontic treatment
What is excessive loss of anchorage?
UNWANTED movement of anchor teeth during orthodontic treatment which prevents dsired tooth movement from occurring
How can we prevent LOA?
move small number of teeth at any one time
keep active forces light
make anchorage root area as large as possible
Which requires more anchorage, full bodily movement or tipping?
full bodily movement as there is more area for which bone has to resorb
What is the disadvanage of intermaxlliary anchorage?
this can sometimes lead to the over eruption of posterior teeth and reduction of the overbite
What are the groups os intra oral traction?
simple: one tooth
compound: several teeth
reciprocal: 2 groups of teeth are pitted against eachother so get movements in both sets, this is needed in palatal expasion
When would we use head gear?
to move all teeth distally
when there is not enough I/O anchorage
What are the two types of head gear?
cervical pull
high pull
How does cervical pull work?
this is at the level of the occlusal plane and causes the upper molars to extrude so cannot be used in people with increases lower facial height
How does high pull head gear work?
this is placed above the occlusal place
How long does the head gear need to be worn?
10/12 hours
How much force is exerted by hed gear?
200-250g