Fixed Orthodontic Appliances Flashcards
what is the definition of a fixed orthodontic appliance?
- appliance which is fixed to teeth & cannot be removed by pt
- consists of brackets, bands, archwires & auxiliaries
- precision tooth movers
what do FIXED APPLIANCES provide?
- 3D control
- complex tooth movements
- control of root
- less dependant on pt compliance
- requires excellent OH
- risk of iatrogenic damage
- poor intrinsic anchorage
what do REMOVABLE APPLIANCES provide?
- simple tooth movements, tipping & tilting
- no control over root movement
- greater pt compliance needed
- less risk of iatrogenic damage
- good intrinsic anchorage
- they can break or get lost
when do we use fixed appliances?
- correction of mild to moderate skeletal discrepancies (orthodontic camouflage)
- alignment of teeth
- correction of rotations
- centreline correction
- overbite & overjet reduction
- closure of spaces/creating spaces
- vertical movements of teeth
What is the GOAL/STANDARD called that orthodontic tx aims to achieve?
Andrews six keys
What is andrews six keys?
ideal end point for ortho tx
- no interproximal spaces, no rotations
- class 1 molars
- class 1 incisors
- flat occlusal planes (or slight curve spee)
- correct crown angulation
- correct crown inclination
what are the components of a fixed appliance?
- bracket/tube
- band
- archwire
- modules
- auxiliaries
- anchorage components
- force generating components
what are the 3 main components of an orthodontic bracket?
- bracket slot
- tie wings
- bracket base
what are some of the materials that orthodontic brackets are made from?
stainless steel, cobalt chrome, titanium, gold
What does the bracket prescription determine?
the tip, torque and in/out control of the brackets being placed
how are orthodontic brackets bonded to teeth?
- composite with acid etch technique
how are molar bands bonded to teeth (for anchorage)?
glass ionomer
what are orthodontic archwires usually made of?
- stainless steel
- nickel titanium
what are the properties of nickel titanium that make it good for archwires?
- flexible
- light continuous force
- shape memory
- higher friction than stainless steel
what are some force generating components in ortho?
- elastic power chains
- Nickel Titanium coils
- intra-oral elastics
- active ligature
[the teeth move by utilising the energy stored in the elastic or spring]
what is anchorage?
the resistance to unwanted tooth movement
what is a new thing that can provide ABSOLUTE ANCHORAGE?
non osseointegrated mini screw
major development in orthodontics
what is cortical anchorage?
Using dense cortical bone as a stable foundation for orthodontic anchorage
[example, transpalatal arch with nance button]
what are the purpose of retainers?
PASSIVE orthodontic appliance used to maintain the final tooth position
what are the 2 categories of retainers?
fixed retainers
removable retainers
what are dental features with a HIGH RELAPSE potential?
- DIASTEMA/Space Closure
- Rotations
- Palatally ectopic canines
- proclination of lower incisors
- anterior open bite
- instanding upper lateral incisors
what is a hawley removable retainer?
a retainer with a labial bow to control incisors and canines
(not well tolerated in the lower arch)
when can fixed orthodontic retainers be used?
- spaced closure/diastema
- proclination of lower labial segment
- periodontal cases
- ectopic canines
- instanding upper 2s
what are the main risks with fixed appliances?
- decalcification
- root resorption
- relapse
what is your role as the GDP with a patient with fixed orthodontic appliances?
- continue routine checkups
- reinforce OHI & diet advice
- liaise with orthodontist IF concerns
- MAKE SAFE in case of orthodontic emergency (sharp wires, loose components, etc)
