W7 - Clear Aligners - Coyne Flashcards
What malocclusions are worsened by ortho aligners? Why?
Deep bites
Class 3
Principles of ortho tx (5)
- Gather records
- Diagnosis - problems?
- Aims of tx - What do you want to achieve
- Tx options
- Treatment
What must you be sure the patient is aware of before beginning aligner tx?
Root shape change / root resorption
Features of clear aligners therapy
- 3D printed - either direct of thermoformed on a model
- Proactive (vs reactive like braces)
- Envisage where you want teeth to go
- Need space for teeth to move
- Need force to apply to tooth
Advantages of clear aligners (6)
Aesthetics
Removable
Comfortable
Compromised/missing teeth
Protection from parafunction
No emergencies (unlike broken braces)
Disadvantages of clear aligners (3)
Removable
Compliance
Some movements are difficult
How long do aligners need to be worn for?
24 hours per day with 2 hours off to eat
Why may aligners cause lateral posterior open bites? (2)
Anterior interference (did not accomodate for material thickness posteriorly)
Missed class 3
How to manage common problems regarding aligners (3)
Lag / off track → What’s the main issue? Rescan or continue
Lost aligners → Keep old sets or skip ahead
Compliance → can always swap to braces
How does tooth movement differ btw aligners and braces
Braces push and pull
Aligners can only push (must have surface area for aligner to push)
Why may aligners require attachments / buttons?
Requires surface to push on
Ex. buttons → give aligner something to push down on
What tooth movements require attachments in aligner tx? (5)
Posterior rotations
Extrusions
Bodily movement
If tx requires elastics
Expansion (moving buccally)
Why dont anterior rotations require attachments?
Enough broad suface area for aligner push
How do attachments relate to couples and moment forces
Since we are unable to put a bracket on centre of resistance, a moment will be created (rotation/tipping)
- Braces usually have a bracket (couple) to create counter force and thus whole bodily movements
- Aligners will require attachment to achieve the bodily movement
Do you need attachments for intrusion?
Not on the specific tooth → however, must place on supporting teeth
Where is the attachment needed for extrusion? what must be considered?
Make sure there is room for tooth to be extruded
Why do aligners make class 3 worse?
Why is it good for open bites?
Aligners will apply intrusive force on posterior teeth
md rotates forward, making class 3 worse
- good for open bite
- bad for deep bite
Reasons for treatment monitoring (6)
Evaluate fit of aligners
Monitor treatment
Adapt tx plan to patients biological response
Improve patient compliance
Increase efficiency (reduce unneccessary appts, anticipate upcoming appts)
Provides better pt experience (more convenient, feedback/updates)
- Can get pt to track their own progress virtually, assess to shorten time
- if tracking well can shorten, if not, lengthen time
How often to change aligners?
Adults - usually every 14 days
Growing kids - every 10 days, 7 days
Depends on pt specific biology
- Can get pt to track their own progress virtually, assess to shorten time
- if tracking well can shorten, if not, lengthen time
What is the hybrid model of modern orthodontics?
In-office AND virtual consult / appointments
- Better treatment monitoring
- Pts can track their own progress
What records are needed for digital orthodontics? (5)
Intraoral scanning
Intraoral photos
Extraoral photos
OPG / Lat ceph / CBCT
3D facial scans & dynamic records
What is digital orthodontics?
Use of technology to collect information, analyse problems, formulate a treatment plan, manufacture the appliances, execute the treatment and monitor the progress using systems and digital technology
Ex. iTero scanning, 3D printing, automatic lat ceph tracing, digital tracking, etc.
How do you monitor treatment progress?
Can do physical appts
Digital better → get pt to take pic / scan teeth at set intervals (ex. daily)
- Can encourage pt to stay compliant because if they are ontop of their scanning, you may be able to reduce treatment time (aka see if they are ready for their next tray or not)
- Track how frequently (or lack of) aligner being used
What are common ortho problems GP’s miss when doing aligner tx (5)
Class 3
Skeletal discrepancy
Growth patterns
Deep bite
Bite jump correction
Why do you need attachments for expansion? (4)
Otherwise it will lead to tipping outwards → palatal cusps extruded → interference → lateral openbite
