Class 5 Flashcards
Removable appliances advantages
Removable
More hygienic
May be more esthetic
Easier for certain growth modification treatment than fixed appliances
Removable appliances disadvantages
Relying on patient compliance
Less precise force control than fixed appliances
Involves lab work
Removable appliances primary use
Growth modification
Minor tooth movements
Retention
Bionator
Stimulate mandibular growth
Control tooth eruption
Twin block
Stimulate mandibular growth
Can include an expander
Can add headgears
Frankle Appliance
Completely tissue borne
Buccal shields or lip pads to reduce cheek and lip pressure for expansion
Stimulate mandibular growth
Reverse Pull headgear
For preadolescent exhibiting maxillary deficiency
Anterior bite plates
To decrease overbite
Posterior bite plates
To increase overbite
Spring Retainers
Used for both retention and minor tooth movement
Tooth Positioners
Used for minor tooth movement and retention
Is fabricated on set up models to which desired tooth movement has been included
Begg Appliance
Added axullary springs for root control
Contact is very small and friction is Minimal—> teeth can be moved quickly but hard for root control
1st order bends are needed to
Compensate for horizontal position variations
Pre-adjusted edgewise
Make the bracket base of upper lateral incisor lower in Soros thicker while the molar tube profile shorter than adjacent bracket slots
Mesial distal angulation
By varying bracket slot tipping the diffference for tooth long axis angulation are compensated for
2nd order bends
Needed to change mesial distal angulation
Third order
By varying the slot bracket angle or differential changing the bracket base thickness the differences of tooth labial lingual angulation are compensated for
Typical components of modern edgewise appliances
Bands with molar tubes
Brackets
Archwires
Auxiliaries -elasometic chains, coil springs, lingual arches, transpalatal bars, extra oral appliances, temporary anchorage devices
Open coil springs
For opening space retracting teeth
Closed coil springs
Maintaining space
Pendulum appliance
For molar distalization
Bonded to premolars
TMA wires with helixes inserted to molar tubes
Anchorage from palate
Primarily molar movemnt with some movement of anterior teeth as well
Helixes are used for
activation and increase the range of tooth movement
Tongue Crib
For correcting tongue or finger habit
F/D does not include
The geometry of the specimen in the calculation s
Extrinsic stiffness measured by
F/D curve
Intrinsic stiffness measured by
S/S curve
Springback
Ability to return to original shape
Range
The distance a wire can be bent before permanent deformation
Strenght
stiffness x range
Resilience
Area under the S/S curve out to the proportional limit
Formability
Amount of permanent deformation a wire can withstand before failure
Ideal orthodontic wires
High strength Low stiffness High range High formability Cabibilthy of solder
Adding loops to archwire
Increase length =increases range and springiness
NiTi Wires
Low stiffness
Good Strenght
High range
Poor formability
Initial alignment archwire
NiTi or SS
Leveling archwire
TMA or SS
Torquing wire
Rectangular SS or TMA
Finishing archwire I
SS or TMA
Center of resistance
A point at which resistance to movement can be concentrated for mathematical analysis
Root resorption C moves
Coronally
Alveolar bone loss C moves
apically
If the line of action of a force does not pass through the C the force will
Produce some rotation of the tooth. This potential for rotation is measured as a moment
Center of rotation
The point around which an object is rotating
Can C rot be changed
Yes to achieve different types of tooth movement and clinical goals
Translation all point on an object move
In the same direction at the same rate
To produce translation, the line of action of a single force
Needs to pass through C res
It is _______ rather than the point of attachment determines whether translation is produced
Line of action
