ortho anchor Flashcards
orthodontic anchorage
resistance to unwanted tooth movement
what provides orthodontic anchorage
Other teeth and the palate/head/neck/screws in bone somtimes
what is the optimal force for moving a tooth
Lightest force that produces tooth movement at a near maximum rate
what happens as you increase the PDL volume over which a reaction force is distributed relative to the tooth trying to move
Greater the relative movment
what is the ratio between PDL pressures for the movemment tooth and anchor teeth
3:1 (larger anchors are better)
what happens to the anchor if you increase force toomuch
Burning of the anchorage (makes anchorage control impossible)
what teeth make the best anchors
Larger teeth
what is the simplest anchorage
Reciprocal anchorage
what is reciprocal anchoage
movememtn of one tooth is pitted against one exactly like it or with the same anchorage value
when to use reciprocal anchorage
close maxillary diastema
what is the result of reciprocal anchorage
Movement towards each other at the same rate
what is reinforcing the anchorage
when you add more teeth to the anchor so the teeth trying to move are moved and the anchor teeth are not moved
- can include headgear outside the arch( but rarely)
what is stationary anchorage
using bodily movement on the anchor to serve as an anchor so it doesn’t really move that far
how much force to use for a stationary anchorage
Below the optimal force
how fast does cortical bone remodel compared to medullary
Cortical Remodels much slower
how to do space closure by sliding
first retract canine
add to posterior anchorage unit as incisors are retract
what is a determinate force system
You can measure and determine the face and moments felt by all teeth
what does an indeterminate force system mean
impossible to know exactly what forces and moments are produces
what force systems are indeterminate
two-couple systems
what is a one couple system
couple present atone place and forces without a couple are felt elsware
do removal appliances become two couple systems
No
what tends to becomes two-couple systems
Multi-bracketed fixed appliances
what does the rectabgular wire create
a couple within the bracket in the toqure plane of space
moves tooth around if wire is flexed
what tends to happen to teeth as you do ortho
TEnds to be extrusive
how to set up an appliance for intrusion
must bypass teeth 2x4 appliance (2 molars, 4 incisors)
when cant you intrude teeeth
With cont arch wire
two couple systems
can you move ankylosed teeth
No
what odd things make good anchors
Ankylosed teeth
implants
youngest to get temporary skeltal anchors
11
what are the types of Remporary skeletal anchors
bone screws in alveolar bone
Miniplates attached to basal bone beneath the teeth by multiple bone screws
why use miniplants over bone screws
when more extesnive movement needed
why use temporary skeletal anchors
- Position individual teeth when no anchor avaiable
- Intrsuion of posterio teeth to close ant open bite
- retract and intrude protruding maxillary incisors
- distal movement of molars
how to restract max incisors with TADs
- Using bone screws in palate to stabilize lingual arch
- using bone screws in the alveolar process posteriorly
- using mini-plates placed at the base of the zygomatic arch (arm projecting into vesibule)
where must bone screws be attached
attached gingiva
what kind of force do bone screws struggle with
Vetricle foce
what happens if you use a miniplate anchorage against the zygomatic buttress above the roots of the teeth
CAn move the entire maxilary arch posterior if space is avaialable (need to remove 3rd molar, sometimes second molar)
