contemporary orthodontics Flashcards
3 main types of appliances used in orthodontics?
1)Growth modifications on appliances
Appliances that move teeth within bony 2)envelopes
3)Retainers
What is the aim of growth modification appliances?
to alter growth
How do we choose which appliance to use in ortho?
The aim of the treatment determines the most appropriate appliance we need to use,
therefore accurate diagnosis is important
What might we want our orthodontic appliances to achieve/improve?
Improve-
Appearance
Function
Health
What qualities do we ensure the appliance offers
Comfortable treatment
Acceptable look during the treatment
Acceptable treatment time
Lowest possible risk
Long term stability
List the different type of growth modification appliances
Class II growth modification
Class III growth modification
Transverse change
What is the aim of class II growth modification appliances?
To improve class II dental and skeletal relationship
examples of class II growth modification appliances?
Functional appliance
Headgear
At what age are class II growth modification appliances most successful
pubertal growth phase: 11-14 years
the different types of functional class II growth modification appliances
1) Removable ( 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
only remove when eating/sports/to clean
Describe what a twin block functional class II growth modification appliance:
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 aims do functional class II growth modification appliances
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 appliances §
What are some of the risks 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 sports
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
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?
pulls maxilla froward using the frame as anchorage
This promotes maxillary growth
How long do you need to wear a protraction face mask
> 14 hrs a day
At what age is a protraction face mask most effective
8-10 yrs
What are the benefits of a protraction face mask?
1) 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
he aim of transverse change appliances?
To correct inter arch transverse relationship usually by expanding the maxilla to correct buccal cross bite
When do dentists use transverse change appliances?
Before the mid-palatal suture has fused
Around 14-15 years but large variation
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
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 the tongue presses against the appliance
Noises+soreness when turning the screw
Nose bless can occur (not common)
If the bone does not split there’s a risk of pushing teeth buccal through cortical bone
there is a
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
categorise fixed appliances
By design
Attachment surface
Material used
how can we categorise fixed appliances by design?
1)
Conventional winged
2. Self-ligating
how can we categorise fixed appliances by attachment surface?
Buccal/lingual
how can we categorize 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
Variable force
The bracket and wire enable force to be transmitted to the tooth
What is more important bracket design or wire characteristics?
Wire size shape and material only
The 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 the clinician
Can correct less severe AnteroPosterior, vertical, and transverse issues
Can be used with other appliances to increase the scope of tooth movement
What is the risk associated with fixed appliances?
Can be uncomfortable
Risk of decalcification
Can cause root resorption
Risk of gingival recession if tooth movement is not planned well
Can only move teeth within the existing bony envelope
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?
Supports 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 removable orthodontic appliances?
To correct malocclusion by repositioning teeth within existing bony envelopes
How is tooth movement achieved by removable orthodontic appliances?
1)Active wire component
2) Thermoplastic material
Give examples of removable orthodontic appliances that uses an active wire component.
1)
Traditional URA
2. Barré appliances
What makes up 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
A good adjunct to other treatments
Can be useful interceptive devices
What are the risks associated with traditional URAs?
Can be uncomfortable
Can impact speech
has a Limited scope for tooth movement
what is a a Barré appliance>
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
what do aligners 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 patient’s mouth
Transfer all information digitally to the 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 aligners?
Can be uncomfortable
Removable so compliance can be an issue
Still limiting tooth movement
Not easily adjusted by clinician
The software uses average values
Need a very accurate prescription as all aligners made in a lab
What is the aim of a retainer?
To resist relapse by holding the teeth in their new position
How can retainers be classified?
1)Removable
2. Fixed
Give examples of removable retainers.
1.
Vacuum formed
2. Hawley
How can fixed retainers be classified?
Direct or indirect
By type of material
By design and material
