Biological Principles of Ortho Tooth Movement Flashcards
These bone cells are found ahead of the drifting tooth where there’s resorption.
Osteoclasts.
Osteoclasts create these kinds of margins.
Scalloped
Osteoclasts are on the pressure or tension side?
Pressure
This kind of bone is deposited on the tension side, then it’s filled with calcium salts.
Osteoid
These bone cells are deposited behind the drifting tooth.
Osteoblasts
This type of bone is more resistant to resorption
Osteoid
Hyperemia on a tooth is caused by what?
Slight force on the tooth.
Effects of severe forces on dentin and cementum.
May perforate the cementum layer, causing dentin resorption.
These cells repair dentin after active tooth movement.
Cementoblasts.
Be cautious of this in enamel with active tooth movement.
Decalcification
When you try to tip a tooth lingually, where is there the greatest resorption?
Palatal crest
There’s an increased periodontal membrane thickness where?
Apically, past the center of rotation.
Most compression of the PDM is seen where in a lingually tipped incisor?
At the alveolar crest
Optimum force on a tooth is slightly above what?
Capillary pressure
Optimum force on a tooth compresses the PDM by what fraction on the pressure side?
1/3
The PDM can be crushed (pressure side) or torn (tension side) is there’s this kind of pressure.
Excessive
The range of optimum force for ortho movement.
50-200 grams
Where is a tooth’s center of resistance?
On the root
Forces have to be directed here in order for the toop to translate, and NOT tip.
Center of mass/rotation
Tipping movements of teeth are mostly done with these kinds of appliances.
Removable
Bodily movement is also known as what?
Translation
What kind of forces are needed for pure rotation of a tooth?
Equal and opposite
Bodily movement is mostly done with these kinds of appliances.
Fixed
Bodily movement of a tooth applies forces where?
In more than one point
This type of force slows orthodontic tooth movement because osteoid is deposited on the pressure side during recovery.
Intermittent light force
The ideal force in ortho for tooth movement.
No osteoid bone is formed.
Continuous light
Elastic fibers located here reorganize SLOWLY.
Alveolar crest
A beam that’s fixed at only one end.
Cantilevered beam
The simplest spring.
Cantilevered beam
The displacement of a spring is directly proportional to the load/force.
Hooke’s Law of Elasticity.
Resistance to bending.
Stiffness
When the object goes back to its unstretched state.
Unloading
Absorbs energy
Loading
Releases energy
Unloading
Stiffness increases as length _______.
shortens
Stiffness increases as diameter _______.
increases
The maximum force to which something can be stretched so you don’t permanently deform it.
Elastic Limit
High modulus means what?
Stiff
Low modulus means what?
Elastic
Deflection up to the elastic limit.
Range of activation.
How do loops and helices affect stiffness?
Reduce stiffness
