Invisalign Concepts (Lindauer)

Question 1

What uses a series of clear plastic aligners to put forces on teeth to move them?

Answer 1

Invisalign

Question 2

What was the difference with invisalign versus the positioners and spring aligners orthodontists had previously been using?

Answer 2

Digital aspect allowed for a series of trays so teeth could be moved in sequence

Question 3

What are 6 appropriate case types for Invisalign?

Answer 3

1. Mild spacing (1-3mm)
2. Moderate spacing (4-6mm)
3. Mild crowding (1-3 mm)
4. Moderate crowding (4-6mm)
5. Narrow arches (dental, not skeletal)(4-6mm)
6. Relapse cases that meet the above criteria

Question 4

Of the following, which are considered easier (therefore start with these) and what are harder (therefore treat these cases after experience): Space closure
Reproximation (with Interproximal reduction)
Dental Expansion
Flaring
Distalization
Lower incisor extraction

Answer 4

Easy: space closure, expansion, a little flaring

Difficult: distalization, lower incisor extractions

Question 5

Are cases requiring rotation of premolars and canines appropriate for Invisalign?

Answer 5

No

Question 6

Should invisalign be used in mixed dentition cases?

Answer 6

No

Question 7

Should invisalign be used in cases to correct one arch when the opposing arch is being treated with fixed appliances?

Answer 7

No

Question 8

What is the drawback with the literature on Invisalign

Answer 8

Mostly case reports, only a few scientific studies

Question 9

What did the Pearson, Trosien study show that is a huge advantage of invisalign?

Answer 9

Maintained or improved oral hygiene. The patient can take them out and clean.

Question 10

With the removable aspect of Invisalign, what is the big problem with them?

Answer 10

Compliance

Question 11

What does an activation in Invisalign mean?

Answer 11

A new tray

Question 12

What is PAR?

Answer 12

Peer assessment rating. Measures occlusal complication. The higher the PAR, the more difficult the case

Question 13

The Bollen Study of 51 pts looking at hard and soft aligners in 1 week or 2 week activation cycles, as well as high and low PAR showed what for hard vs soft, and best length of time between activations?

Answer 13

2 week intervals better than 1 (37% vs 21%)
Low PAR better than high (38% vs 18%)
Soft vs hard: They use hard now, so it must be hard

Question 14

What is the drawback of the Bollen study?

Answer 14

Only 29% completed all aligners

Question 15

What was the finding of the Patel study that looked at the reduction of PAR pre-and post invisalign?

Answer 15

Average PAR reduction of 50.7%

Question 16

When invisalign and braces are compared with respect to reduction of PAR, which shows the better improvement?

Answer 16

Orthodontics (77% PAR decrease)

Invisalign (50.7% PAR decrease)

Question 17

What is a big difference when comparing the invisalign study versus the traditional ortho study with respect to PAR?

Answer 17

Orthodontics started with higher PAR and ended with lower PAR, where invisalign’s PAR was lower already at pretreatment

Question 18

Djeu study comparing comparable pre treatment PARs of invisalign versus traditional ortho showed what?

Answer 18

Ortho had lower PAR at end of treatment

Question 19

Which has better alignment early on, but relapses more: invisalign or traditional braces ?

Answer 19

Invisalign

Question 20

Lindauer’s study set up with 20 invisalign vs 20 braces matched for pre-treatment difficulty showed what overall improvement percentages?

Answer 20

91.8% improvement for conventional 68.7% improvement for Invisalign

Question 21

What is Little’s Irregularity Index?

Answer 21

Measures contact points between adjacent teeth and adds them together around the arch

Question 22

What did the Kravitz study show when he compared the Clin-Check software of invisalign to the actual final results after invisalign treatment?

Answer 22

Clin-check was 41% accurate

Question 23

Kravitz found the least accurate tooth movement for invisalign is what?

Answer 23

Extrusion

Question 24

Which tooth has better success for rotation with Invisalign: maxillary central or mandibualr canine?

Answer 24

Maxillary Central 54% success Mandibular canine 29.1% success

Question 25

Krieger studied invisalign’s ability to correct anterior crowding via comparing differences in the Little’s Irregularity Index pre-and post-treatment. What did they find

Answer 25

Found Clin-Check was acceptable 5.39mm Little’s maxillary pretreatment 1.57mm Little’s maxillary posttreatment 5.96 mm Little’s mandibular pretreatment 0.82 mm Littles mandibular posttreatment

Question 26

Krieger study said clin-chek predicted well everything EXCEPT what prediction?

Answer 26

Overbite correction

Question 27

Shalish study comparing patient comfort of Invisalign, conventional bracketing, and lingual bracketing found which was most uncomfortable, had greatest disfunction and longest recovery?

Answer 27

Lingual braces

Question 28

The Shalish study comparing patient comfort found what findings for pain and recovery with respect to Invisalign?

Answer 28

More pain initially but a shorter / faster recovery

Question 29

The Shalish study comparing pt comfort found what with respect to recovery for conventional brackets?

Answer 29

Did not recover in 2 weeks

Question 30

Does invisalign cause more, less or the same amount of root resorption as conventional ortho?

Answer 30

No proof. Only a case study showing there is resorption.

Question 31

What is the invisalign cost to a practitioner to get certified?

Answer 31

1 day course = $1,995

Question 32

Almost all patients require what with invisalign treatment?

Answer 32

Refinement

Question 33

What is increased and what is decreased with invisalign versus conventional ortho?

Answer 33

Invisalign has higher lab cost, but less chair time than conventional

Question 34

Why does Linduar think ortho will more in the direction of invisalign?

Answer 34

Offers improved oral hygiene