Fixed appliances Flashcards
Define fixed applainces
appliaance that is attached to teeth by bands (or bonds) and brackets
cannot be removed by pts
How do fixed appliances move teeth?
arch wire puts pressure on brackets and teeth and their attachment on the bands
How does a fixed appliance differ in terms of tooth movement in comparison to a removable appliance?
capable of greater range tooth movements that a RA
What kind of tooth movements can the attachment (bracket) allow?
tilting, vertical, rotational, apical
Name 6 types of treatment for orthodontics
removable appliances fixed appliances monitoring extraction only retainers growth modification with a functional appliance- twin block
what do functional appliances aid and give an example
growth modification
twin block
By which 5 methods do fixed appliances deliver optimal tooth control
bodily movement rotations intrusion/extrusion uprighting root torqueing
which kind of appliance allows tipping movements and why can tipping be better then bodily movement?
removeable
can produce more rapid tooth movement that bodily movements
define bodily movement
shifting tooth along the occlusal plane without changing the orientation of the long axis
crown and root moved in the same or opposite direction
3 reasons bodily movement is used
correct skeletal discrepancies
space closure- from extraction or hypodontia
overjet reduction
define rotation of a tooth
turning a tooth about its long axis
what kind of movement does extrusion/intrusion achieve
vertical
define intrusion and extrusion
extrusion- moving a tooth out of the supporting structures
intrusion- moving a tooth into the supporting structures
What is intrusion/extrusion used for?
overbite reduction
define root torqueing
moving the tooth bucco-lingually so crown and root move in opposite direction
define lingual torque
crowns are tipped lingually and root labial/buccally
define buccal/labial torque
crowns are tipped buccally and roots lingually
define crown tipping
tilting of the crown of the tooth without moving the apex
define root tipping
tilting of the root of the tooth without moving the apex of the crown
when would fixed appliance be indicated?
when precise tooth movements are required
give a disadvantage of fixed appliances compared to removeable and functional appliances
not as effective at moving blocks of teeth compared to RA and functional
what is the difference between edgewise bracket and pre-adjusted?
edgewise- straight slot cut in to brackets. tooth position determinded by bends in arch wire or orientation of the bracket slot/base
pre-adjusted= slot pre-angulated/pre-torqued
minimal archwire bends`
name the 2 types of fixed applianced
labial- preadjusted edgewise and tip-edge
lingual
define ligation
the means by which an archwire is held inside the bracket
name and describe the 2 types of ligation
conventional ligation- elastic or metallic ties hold archwire in place
self-ligating- liagation built into bracket, clips hold archwire in bracket
describe the types of bends required in an archwire to produce types of tooth movements
1st order bends- in out bends, made in the plane of the archwire
2nd order bends- tip, made in vertical plane
3rd order bends- torque, bend in archwire , placed in brackets, when the wire goes back to its original shape it takes the teeth with it
Describe the 6 components of a fixed appliance component
brackets- can be carried on a band and the band then cemented on to tooth or cemented directly on to tooth
molar bands- rings that encircle tooth- bracket attached to this
archwire- initial stages use flexible type, latter rigid type
ligatures- elastic coloured band on brackets to keep archwire in place
auxillaries- elastic bands- pulling maxilla/mandible- used for traction
adhesive- most popular for cementing bands is GI- composite resin sandwich
define composite resin sandwich in relation to adhesives
unfilled resin at tooth surface and near the bracket and between this have filled resin
define traction
act of drawing or pulling
name 4 materials used for archwires
stainless steel
nickel-titanium
beta-titanium
glass/composite
which material of archwires would be ideal for later stages of treatment and why?
stainless steel as it has inhibits good stiffness
which arch wire material is generally used in the initial stages of treatment?
nickel-titanium
list the 6 stages of fixed appliances
anchorage control alignment/levelling overbite reduction overjet reduction space closure finishing/detailing
describe the final stage in fixed applainces: finishing/detailing
place small bends in archwire to fine detail tooth position and occlusion
what are TADs and what are they used for
temporary anchorage devices
used for distal movement of upper molars
describe the 6 keys occlusion
what the finished result should include: class I molars no spaces no rotations normal angulation normal inclination flat occlusal plane
How are bands and brackets removed?
forceps
describe types of retention
fixed- wire
removeable- pressure formed retainer and hawley type (metal)
describe 7 problems that can arise due to fixed applaince treatment
demineralisation/caries- poor OH root resorption- e enamel fracture at debond (when removing cement) periodontal destruction gingivitis pulp death ST trauma- wire pokes
why can root resorption occur
due to excessive forces
