Ortho 2 Test One Flashcards
What is the optimal force to create rotational movement of a tooth?
35-60 gm
What is the optimal force to create translational movement of a tooth?
70-120
What is the optimal force to create intrusive movement of a tooth?
10-20
What represents stiffness in a force-deflection curve?
Slope
At what point does permanent deformation occur?
The yield point
What three things are prescribed with orthodontic brackets?
- Torque, 2. Angulation and 3. Offset
What is the traditional retainer?
Hawley’s retainers
What is the type of retainer that is clear?
Essix retainer
What is the unmineralized, organic portion of bone called before it remineralizes?
Osteoid
What is the breakdown of bone?
70% inorganic, 25% organic and 5% water
How long does it take for woven bone to be replaced by lamellar bone?
12 weeks
What is the anchorage value of the tooth equal to?
Its root surface area
What is the minimum amount of time between ortho appointments?
3 weeks
How long does undermining resorption take to occur?
7-14 days
What tends to work best if an ortho patient needs an endo?
Fill the canal with calcium hydroxide and perform endo after tooth movement has been accomplished
How does orthodontic treatment affect roots?
It makes them shorter, but not thinner
What are the three categories of orthodontic root resorption?
- Slight bunting, 2. Moderate resorption (= 1/4), and 3. Severe resorption (>1/4)
What percentage of teeth show root resorption in ortho?
50% overall and 90% of max. incisors
What is the incidence of moderate to severe root resorption?
3% juvenilles and 4% adults
What orthodontic movement is most associated with root resorption?
Intrusion
What results from continual tongue pressure against the teeth?
Crenated tongue
What does an occipital pull headgear restrict?
Anterior and inferior maxillary growth
What does a cervical pull restrict?
Superior and anterior maxillary growth
What is the range of maxillary expansion using a jackscrew?
5-15 mm
