contemporary orthodontics Flashcards
List the 3 main types of appliances used in orthodontics
- Growth modification`tion appliances
- Appliances that move teeth within bony envelopes
- Retainers
What is the aim of growth modification appliances
Aim to alter growth
How do we choose which appliance to use in orthodontics
The aim of the treatment determines the most appropriate appliance
This is by accurate diagnosis is key
What might we want our orthodontic appliances to achieve?
Improve:
- Appearance
- Function
- Health
What use we ensure the appliance offers
- Comfortable treatment
- Acceptable apparente during the treatment
- Acceptable treatment time
- Lowest possible risk during treatment
- Long term stability
List the different type of growth modification appliances
- Class II growth modification
- Class III growth modification
- Transverse change
What is the of class II growth modification appliances
To improve class II dental and skeletal relationship
Gove examples of class II growth modification appliances
Functional appliance
Headgear
At what age are class II growth modification appliances most successful
During pubertal growth phase: 11-14 years
Name the different types of functional class II growth modification appliances
- Removable eg twin block and modem opening activator
2. Fixed
How long does a patent need to wear a removable functional class II growth modification appliances
22 hours a day
Only remove for cleaning, eating and sport
Describe what a twin block functional class II growth modification appliances
Two pieces that touch together to force the patent to bite forward
What is a medium opening activator
A single piece that patient bites into
Describe a fixed functional class II growth modification appliances
An appliances that attaches from an upper molar to a lower tooth
Piston arms force patient to bite forward
What affect do functional class II growth modification appliances
Mostly dental eg:
- Procline lower incisors
- Retrocline upper incisors
- Change molar relationship for class II to class I
Can also correct deep bite
What are the benefits of functional class II growth modification appliances
- Can correct class II malocclusion
- Can have a vertical effect
- Small improvements in gavial appearance
- Can be used with other fixed appliance §
What are some of the risk associated with functional class II growth modification appliances
- Failure rate through non compliance
- Can impact on quality of life eg speech, eating, discomfort
- Need to take out for sport
Describe head gear class II growth modification appliances
- Needs to worn more than 14 hours a fay
- Only take off for school or sleeping
- Do not wear for eating or sports
What effect does headgear class II growth modification appliances
Mostly dental eg:
- Retract molars
- Reduce overate by retroclining upper incisors
Head gear can also be used to reduce vertical proportions to correct anterior open bite
What are the benefits of headgear class II growth modification appliances
- Correct class II malocclusion
- Little changes to facial appearance
- Can be used in combination with other functional class II growth modification appliances
What are the risks associated with class II growth modification appliances
- Failure rate through non compliance
- Can be difficult to get sufficient hours
- Risk of damage to intramural, skin and eyes if not fitted properly
What is the aim of Class III growth modification appliances
To correct class III dental and skeletal relationship by either:
- Promoting maxillary growth
- Restricting mandibular growth
- Combination of both
Name the different types of Class III growth modification appliances
- Protraction face mask
- Reverse functional
- Chin cap
What is a protraction face mask
A frame that sits on chin and forehead that has elastics to make it fixed or removable
What does a protraction face mask do
It pulls maxilla froward using frame as anchorage
This promotes maxillary growth
How long do you need to wear a protraction face mask
At least 14 hours a day
At what age is a protraction faec mask most effective
Age 8-10
What are the benefits of a protraction face mask
- Can correct class III malocclusion
2. Can promote change to facial appearance
What are the risks associated with a protraction face mask
- Failure rate through non compliance
- Can be difficult to get sufficient hours
- Impacts quality of life
- May not prevent the need for further treatment
What further treatment might be needed following a protraction face mask
1/3 Of cases need orthodontic treatment later in life
1/3 of patients may still need OGN surgery
What does a reverse functional class III growth modification appliance aim to do
Push the mandible back and the maxilla forward
What is a chin cap Class III growth modification appliances
A cup on the chin and elastic force around the top of the head
This aims to retrain the mandible
Out of the 3 Class III growth modification appliances which is the main one used in the UK
Protraction face mask
What is the aim of transverse change appliances
To correct inter arch transverse relationship usually by expanding the maxilla to correct buccal cross bite
When do we often use transverse change appliances
Before the mid palatal suture has fused
Around 14-15 years but large variation
What is a transverse change appliances
A fit appliance that has an open screw that we tighten twice a day to allow of 0.5mm per day expansion of the maxilla
What are the benefits of transverse change appliances
- Corrects buccal cross bites
- Creates space for aligning teeth
- Widens buccal corridor giving better aesthetics
What are the risks of transverse change appliances
- Can be uncomfortable as tongue presses against the appliance
- Noises / soreness when turning the screw
- Nose bless can occur (not common)
- If bone does not split there’s a risk of pushing teeth buccal through cortical bone
- High risk of relapse
What are the aims of fixed appliances
To correct malocclusion by repositioning teeth within existing bony envelope
What are the Stages of fixed appliances
- Align
- Level
- Correct inter arch relationship
- Close spaces
- Root/ crown positioning
How do we categorise fixed appliances
- By design
- Attachment surface
- Material used
how can we categorise fixed appliances by design
- Conventional winged
2. Self ligating
how can we categorise fixed appliances by attachment surface
Buccal or lingual
how can we categorise fixed appliances by material
- Metal
- Ceramic
- Plastic
Name the most common fixed appliance design
Conventional winged
What basic principles do fixed appliances use to correct malocclusion
- 3D control
- Variabel force
The bracket and wire enable force to be transmitted to tooth
What is more important bracket design or wire characteristics
Wire size shape and material
Bracket design doesn’t make much difference
What determines the wire size
Bracket slot size
What are the benefits of fixed appliances
- Excellent for aligning teeth
- Easily adaptable by clinician
- Can correct less severe AnteroPosterior, vertical and transverse issues
- Can be used with other appliances to increase scope of tooth movement
What are the risk associated with fixed appliances
- Can be uncomfortable
- Risk of decalcification
- Can cause root resorption
- Risk of gingival recession if tooth movement not planned well
- Can only move teeth within existing bony envelope
List some appliances that can be used alongside fixed appliances
- Quadhelix appliance
- Transpalatal arch
- Temporary anchorage devices
What does a Quadhelix appliance do
Used to expand t5he maxillary arch
What does a Transpalatal arch do
Support anchorage
What is another name for temporary anchorage devices
Mini screws
What do temporary anchorage devices do
They provide a traction point for force application
What is the aim of fixed orthodontic appliances
To correct malocclusion by repositioning teeth within existing bony envelopes
How is tooth movement achieved by a removable orthodontic appliances
- Active wire component
2, Thermoplastic material
Give examples of a removable orthodontic appliances that uses an active wire component
- Traditional URA
2. Barré appliances
What make sup a traditional URA
- Active component
- Retentive component
- Anchorage
- Baseplate that holds everything together
What are the benefits of traditional URAs
- Correct minor tooth movements
- Highly adaptable
- Good adjunct to other treatments
- Can be useful interceptive devices
What are the risks associated with traditional URAs
- Can be uncomfortable
- Can impact speech
- Limited scope for tooth movement
Describe a Barré appliance
Is a double spring applause used to correct rotation and tip1 only in labial segment
What are the benefits of a Barré appliance
- Can correct minor alignment issues
What are the risks associated with Barré appliance
- Can be uncomfortable
- Can impact speech
- Limited scope for tooth movement
Give an example of a removable orthodontic appliances that uses an thermoplastic materials
Aligners
Describe what aligner do
They are thermoplastic appliances that move teeth incrementally (up to 0.2mm per aligner)
How do we make an aligner
- Take full records of patients mouth
- Transfer all information digitally to lab with prescription
- Use CAD-CAM technology to reposition teeth according to prescription
- Manufacture a series of aligners to increment tally move teeth
How many aligners does ti usually take to correct malocclusion
14 aligners used for 2 weeks each
What are the benefits of aligners
- Good appearance as they are clear
- Can be removed fro social/ oH reasons
- Increasing scope for correcting malocclusion
What are the risks associated with aligner
- Can be uncomfortable
- Removable so compliance can be an issue
- Still limiting tooth movement
- Not easily adjusted by clinician
- Software uses average values
- Need a very accurate prescription as all aligners made in lab
What is the aim of a retainer
To resist relapse by holding the teeth in their new position
How can retainers be classified
- Removable
2. Fixed
Give examples of removable retainers
- Vacuum formed
2. Hawley
How can fixed retainers be classified
- Direct or indirect
- By type of material
- By design and material