Fixed Orthodontic Appliances Flashcards
What components make up fixed appliances?
- brackets/tube
- bands
- arch wires
- modules
- auxiliaries
- anchorage components
- force generating components
What are fixed orthodontic appliances?
- an appliance which is fixed to the teeth and cannot be removed by a patient
- precision tooth movers
Compare fixed appliances with removable appliances
- fixed appliances
- 3D control
- complex tooth movement
- control of roots
- less dependent on compliance
- requires excellent oral hygiene
- risk of iatrogenic damage
- poor intrinsic anchorage
- removable appliances
- simple tooth movements
- tipping
- no control over tooth movements
- greater compliance required
- less risk of iatrogenic damage
- good intrinsic anchorage
- can be lost
- simple tooth movements
When are fixed appliances used?
- correction of mild to moderate skeletal discrepancies
- camouflage
- alignment of teeth
- correction of rotations
- centreline correction
- overbite and overjet reduction
- closure of spaces/creating spaces
- vertical tooth movements
What components make up brackets?
- bracket slot
- tie wings
- bracket base
What materials can brackets be made of?
- metal
- stainless steel
- CoCr
- titanium
- gold
- polymers
- ceramics
What are orthodontic bands and how are they placed?
- stainless steel with pre-welded attachments
- tubes
- cleats
- require space before placement
- separator visit
What is bracket prescription?
- the shape and angulation of the bracket
- determines tip, torque and in/out
How are orthodontic components bonded to teeth?
- brackets and tubes
- composite via acid etch technique
- photo-initiation (440-480nm)
- micro mechanical retention
- composite via acid etch technique
- molar bands
- glass ionomer
What are the different materials arch wires can be made of?
- stainless steel
- nickel titanium
- cobalt chromium
- beta-titanium
- composite/glass
What are the properties of NiTi archwire?
- flexible
- light continuous force
- shape memory
- return to original shape
- cannot bend
- higher friction than stainless steel
- better at small diameters
- good when large deflections are present
What are the properties of stainless steel archwire?
- low friction
- working archwires
- formable
- arch wire bends
- loops
Provide examples of force generating components and how they work
- elastic power chain
- NiTi coils
- intra-oral elastics
- active ligature
- sliding mechanics
- utilise energy stored in component
What problems can present with elastic power chain?
- degrades very quickly
- significant loss of force
- 24-48 hours
- significant loss of force
- patient return with snapped power chain
- inactive
- regular appointments required
What is the function of NiTi coils?
push teeth apart
What is the function of intraoral elastics and what two ways can they be placed?
- use the force of one arch against the other
- Class II elastics
- more anterior on the upper
- more posterior on the lower
- Class III elastics
- more posterior on the upper
- more anterior on the lower
What are active ligatures?
- elastomeric separating module
- long ligature
What anchorage considerations must be made for fixed orthodontic appliances?
- resistance to unwanted tooth movement
- Newtons 3rd law
What is absolute anchorage?
- high anchorange
- temporary anchorage device (TADs)
- non-osseointegrating mini screw
- anchorage control
- tooth movement mechanics
- pre-op radiograph required to determine location of adjacent roots
Where can temporary anchorage devices be placed?
- inter-radicular
- palatal
What increases anchorage for a tooth?
increased root surface area
What is compound anchorage?
grouping teeth together to reduce unwanted tooth movement and increasing desired tooth movement
What is reciprocal anchorage?
two similar teeth with equal root surface area resulting in equal movement
What is cortical anchorage?
- cortical plates utilised
- increased resistance to tooth movement
- maintains intermolar width
- transpalatal arch
- nance button
- utilises palatal vault
- anchorage reinforcement
What is used to provide intermaxillary anchorage?
- inter maxillary elastics
- class II elastics
- upper canine to lower molar
- class III elastics
- lower canine to upper molar
- class II elastics
What are retainers?
passive orthodontic appliances to maintain the final tooth position after completion of orthodontic treatment
When must retention be discussed with patients?
- at the consent stage
- must consent to lifelong retention
Which malocclosion features have a high relapse potential?
- diastema
- rotations
- palatally ectopic canines
- proclination of lower incisors
- anterior open bite
- instanding upper lateral incisors
What are pressure formed retainers?
- clear overlay dentures
- variety of materials and thickness
- can contain prosthetic tooth
- well tolerated
What is the recommended wear pattern for removable pressure formed retainers?
- varies between clinicians
- 2 weeks full time wear
- except eating and drinking
- only nights after 2 weeks
- only night time wear
- for entire life or as long as would like retention
What is a Hawley removable retainer?
- removable appliance
- labial bow to control incisors and canines
- usually URA
- not well tolerated in the lower arch
When are fixed orthodontic retainers recommended
- space closure
- diastema
- proclination of lower labial segment
- periodontal cases
- ectopic canines
- instaning upper laterals
Describe bonded wire retainers
- requires careful monitoring
- ID cleaning vital
- ensure composite attachments are intact
- refer back to orthodontist if problems
- must have occlusal clearance, avoid debond
What are the three main risks of orthodontics with fixed appliances?
- decalcification
- root resorption
- relapse
Describe the patient journey for fixed orthodontic appliances
- assessment and diagnosis
- treatment aims
- treatment plan
- commence treatment
- routine adjustments
- every 4-8 weeks
- initial problems encountered
- pain
- mucosal irritation
- ulceration
- appliance breakage
What is the duration of an average orthodontic case?
18-24 months
What is the duration of a hypodontia case?
24-30 months
What is the duration of an orthognathic case?
24-30 months
What is the role of the GDP in regards to fixed orthodontic appliances?
- see patient for routine care and checkups
- reinforce OHI and diet advice
- liaise with orthodontist is concerned
- make appliances safe in case of emergency
- snipping of jaggy wire
- removal of loose component
