ORTHO fixed appliances Flashcards
(43 cards)
what is a fixed appliance?
- brackets/ bonds attached to teeth
- mainly used in permanent dentition but can be used also as interceptive tx in the mixed dentition
- control of the teeth in 3 planes of space
what is anchorage?
the resistance to unwanted tooth movement during orthodontic treatment, ensuring that only the desired teeth move in the intended direction
why is anchorage important?
It’s a crucial concept because every force applied to a tooth during treatment also generates an equal and opposite force, and anchorage provides a stable base to counteract these unwanted movements
what are the 3 types of tooth movements?
tipping
bodily movements
torque
indications for fixed appliance?
multiple tooth movements needed
rotations
bodily movements
space closure (xla/ hypodontia)
lower arch treatment
contraindications of fixed appliances?
poor OH
active caries
poor motivation
what is diet advice for pts with a fixed appliance?
avoid hard/ sticky foods
restrict sugars and acids
what are the risks of fixed appliances?
decalcification
root resorption
loss of perio support
TMJ dysfunction
failed tx and relapse
what are the reversible risks of fixed appliances?
pain
ulceration
what leaflet is available for pts to inform them about fixed appliances?
British Orthodontic Society - orthodontic treatment, what are the risks?
what are the types of fixed attachments?
bands - usually used on molars/ premolars or teeth with ceramic crowns
bonds/ brackets - perforated or mesh bases held to tooth with acid etch and composite
what may be used to de rotate a tooth with a fixed appliance?
eyelets or buttons
considerations with ceramic brackets?
beware of incisors biting down onto the bracket as ceramic can #
disadvantages of a lingual fixed appliance?
irritation to tongue
what tooth movements does the wire control?
mesio-distal tip
labio-lingual rotation
what is pre-adjusted edgewise or ‘straightwire’?
- built in adjustments for individual teeth
- every bracket is preprogrammed with dimensions of the teeth
- reduces need to put bends in arch wires
*non-average teeth need customisation in finishing stage
types of brackets?
edgewise - require arch wire to bend to produce the ideal ‘tip’
straightwire - pore adjusted brackets have slot cut diagonally across face to build in ideal tooth position
what feature of straight wire brackets allow for labio-lingual contact points to align?
variation in thickness of straight wire bracket bases
what are the 3 phases to active treatment?
- levelling and aligning
- major tooth movement - correction of overjet and overbite, space closure, centre line correction
- finishing - detailed alignment
what is used for the alignment phase?
- light flexible arch wires
- usually arch wires changed each visit
- wires of increasing stiffness
explain how the wires work in alignment phase?
- deformation energy dissipates as wires straighten and pull teeth into alignment
- each new wire is deformed less but has higher deformation energy
what is the usual starting wire for alignment?
014 NiTi
properties of nickel titanium wires?
high flexibility
deliver a low force over a long range
SHAPE MEMORY
what wires are used for major tooth movements?
usually rigid wires
1925 NiTi and then a rigid 1925 SS
