Contemporary Ortho Flashcards
what does ideal treatment look like?
comfortable
good appearance
good treatment time
long term stability
what can be used to improve a Class II occlusion? when is it best used?
functional appliances
headgear
best to use 11-14 - during puberty growth
can be used earlier if bullying or high risk of dental trauma
what are the 4 types of functional appliances for a class II? describe each
- removable
- need to be worn for 22hrs
- remove for cleaning, eating and sport - twin blocks
- force patient to bite forward - medium opening activator
- pt bites onto it - fixed appliance
- attached arm from a upper molar to lower tooth
- piston forces pt to bite forward
what is the desired effect of changing a class II occlusion? (3)
retrocline the upper incisors
procline the lower incisors
change molar relationship from class II to class I
pros and cons of wearing appliances
pros
- corrects the malocclussion
- aesthetic improvement
- reduce vertical proportions to correct an open bite
cons
- fail if non-compliant
- impact quality of life - discomfort, eating, speech
how long do you need to wear headgear?
14 hrs a day
take out for eating and sports
other class III appliances - reverse function and chin cap - how do they work?
reverse function
- aims to push mandible back and max forward
- only vertical changes occur
chin cap
- cup on chin
- elastic force around the head
- aims to restrain the mandible
- not that effective, not used in the UK
risks and benefits of headgear
benefits
- correct class II malocclusion
- can be used with fixed
risks
- failure if non-compliant
- risk of damage to skin, mouth and eyes if not fitted properly
what is the most common appliance for a class III occlusion? how does it work, how often do you wear it and what age?
protraction face mask
- frame sits on chin and forehead
- elastics to fixed/removable maxillary appliance
- maxilla is pulled forward
needs to be worn 14hrs
most effective age 8-10
what is rapid maxillary expansion? when and how do you have to do it?
aim is to expand the maxilla to correct a buccal cross bite
when: before the mid-palatal suture has fused
- around age 14-15
how:
- fit the appliance and open the screw 0.5mm/a day for 1-2 weeks
- needs to hold for 3 month for bony infill
risks and benefits of rapid maxillary expansion.
benefits
- corrects buccal crossbite
- creates space for alignment
- widens buccal corridor - better aesthetic
risks
- uncomfortable
- high risk of relapse
- risk of teeth pushing through cortical bone if the mid-palatal bone does not split
what are the aims and stages for regular fixed appliances?
- to correct malocclusion by repositioning within the existing bony envelope
- align
- levelling arches to be flat
- correct inter-arch relationship
- close space
- root/crown position
what are the types of fixed appliances? design, attachment surface, material
design
- conventional winged
- self-litigating
attachment surface
- buccal
- lingual
material
- metal
- ceramic
- plastic
risks and benefits of fixed appliances.
benefits
- align teeth
- clinician can adapt them well
- corrects mild alignment issues
risks
- uncomfortable
- risk of decalcification
- need to manage diet and OH
- can cause root resorption and gingival recession
- can’t manage with large skeletal issues
describe quadhelix appliance
expands the maxillary arch
mild version of rapid maxillary expansion
describe a transpalatal arch
just supports the anchorage to hold teeth in place when using a fixed appliance
- prevents arch falling in on itself
what are the two types of removable appliances?
URA wire
thermoplastic material - aligners
describe URA wire - what do they need, risk and benefits
always consider the:
- active component
- retention
- anchorage
- baseplate
benefits
- correct minor tooth movements
- adaptable
risks
- uncomfortable on speech
- limited scope for movement
thermoplastic aligners
- how much can they move teeth
- how are they made
- move teeth 0.2mm per aligner
mouth records
digital transfer
aligners are made
CAD-CAM technology is used to reposition the teeth
risks and benefits of aligners
benefits
- aesthetics
- can be removed for social/OH
- alternative to fixed
risks
- uncomfortable
- pt may not be compliant
- limited scope for movement
- not easily adjusted - send back to lab
- software is not precise - uses average values
- need a very accurate prescription
retainers
- aims
- types
to resist relapse by holding the teeth in the new position
removable or fixed
