S2 - Clear Aligner

Question 1

Question 2

What can cause huge issues if failed to recognise

Answer 2

• class IIIs
• skeletal discrepancies
• growth patterns
• deep bite
• bite jump corrections
• need to recognise when you are off track and need a way to get tx back on track

Question 3

Principles of orthodontic treatment (5)

Answer 3

1. Records: Hx, I/O photos and scans, radiographs
2. Diagnosis: summary & problem list
3. Aims of Treatment: how you know when you are done
4. Treatment Options: including no tx and informed consent
5. Treatment: including review & retention

Question 4

What are clear aligners

Answer 4

3D printed - direct or thermoformed on a model

Made from clear plastic

Proactive approach (rather than reactive)

Envisage where you want the teeth to go - need space for tooth to move and need force to apply to the tooth

Question 5

Advantages vs Disadvantages of clear aligners

Answer 5

• aesthetic
• removable
• comfortable
• compromised/missing teeth
• protection against parafunction (bruxism)
• easy to pause tx (e.g. traumatised central incisors)
• removable therefore rely on compliance (24h/day w 2hrs off to eat)
• some movements are difficult

Question 6

Differences between aligners and braces

Answer 6

Question 7

How to manage possible problems which may arise with aligners

Answer 7

• If tx lags/offtracks (space between tooth and aligner): what is the main aim, rescan or continue
• Lost aligners: keep old sets can skip ahead or go back to last one
• Poor compliance: can always put braces on…

i.e. problems can be solved

Question 8

Principles of orthodontics

Answer 8

force applied → areas of compression and tension on PDL, osteoclasts cause bone resorption on compression side, osteoblasts lay down bone on tension side → tooth moves

Question 9

How do teeth move with braces vs aligners

Answer 9

Braces - wires engages w bracket to create a couple - push & pull (bracket/wire interface)

Aligners - can only push teeth - you need space for the tooth to move into and a surface to push on: aligner/tooth and/or aligner/attachment interface

Question 10

Why do you need attachments?

Answer 10

some movements require an additional surface to push on

e.g. in image, to extrude tooth theres nothing to push on, attachment provides this

Question 11

Why do you generally need attachments for posterior rotations but not anterior?

Answer 11

anteriors have flat surfaces to push on whereas posteriors are round therefore nothing to push on, need attachments to rotate

Question 12

What dictates attachment requirement?

Answer 12

type of tooth movements - tipping, bodily, extrusion, intrusion, rotation, torque, support

Question 13

Why are attachments needed for bodily tooth movement

Answer 13

force applied away from COR creates a moment (rotation)

attachments will create the necessary force system to prevent tipping

Question 14

Why are attachments needed for expansion?

Answer 14

bodily movement, otherwise will just tip out

Question 15

Are attachments needed for intrusion and extrusion?

Answer 15

intrusion - need attachments on supporting teeth

extrusions - need attachment on extruding tooth

Question 16

What is important to plan with regards to bone

Answer 16

teeth need to stay in bone! otherwise leads to recession or tooth loss

easy to miss where bone is on digital scan

may need exos or IPR to gain space

Question 17

Why aligners make class IIIs and deep bite worse but help class IIs and AOBs?

Answer 17

thickness of aligner material → intrusive force on posteriors, rotates md forward

Question 18

Why is diagnosis, problem list and aims so important?

Answer 18

• identify problems
• what you can and cant do
• pt needs to understand limitations, can you meet their expectations → refer if need
• define what the planned outcome is, thats how you measure success

Question 19

What is needed for good clinical records

Answer 19

• pt assessment & evaluation
• I/O (mandatory nowadays)
• I/O photos (including incisal edges & gingival margins - track chips and recession) → take photos are every single appt
• E/O photos
• 3D face scans & dynamic records (videos)
• radiographic: OPG and lat ceph at least, CBCT

Question 20

Why are I/O scans useful

Answer 20

• to track movement
• use as part o diagnostic process - multiple setups, IPR vs exo (dont do IPR on growing pts unless rly needed)
• treatment stimulation - for pt education

Question 21

What can treatment monitoring do to increase efficiency**? and provide **better patient experience?

Answer 21

• evaluate fit of aligners
• reduce unnecessary in-office appts
• adapt to patient’s biological response
• anticipate upcoming appointments
• improve pt compliance (as know someones watching)
• better engage, communicate and educate the patients
• more convenient for pt
• provide constant feedback and updates on tx

Question 22

What is pt management moving towards now/in the future

Answer 22

hybrid model

Question 23

How do you decide change rate of aligners

Answer 23

remote monitoring helps match pt’s compliance and biology

might depend on age

assess what is a good fitting aligner

check tracking - if not tracking well might lengthen scan interval and shorten if tracking well

Question 24

What is digital orthodontics

Answer 24

use of technology to: collect information, analyse potential teeth or jaw problems

use digital software to: formulate tx plan, manufacture appliance, execute treatment

monitor process virtually/digitally