Invisalign for extreme crowding….will it work?

In 2004 I had maintained a private practice in the West End for over 9 years and I was doing a lot of cosmetic smile makeovers.

So I naturally wanted to progress and learn more about the art of smile makeovers from the US.

I knew of an eminent clinician in New York who ran a veneer course. So I Googled him, but I came across some very bad reviews. On one website I found an image of one of his failed veneers:


I naturally did not want to fall into the trap of promising excellent cosmetics on shaky ground such as the prepped tooth above.

Now we all know veneers can be very thin or even non prep but how many patients do you see that have straight teeth and want veneers?

In 2004 at an orthodontist’s open evening I stumbled upon Invisalign. I went on the course and certified as an Invisalign provider.

On the Monday morning after the first patient that I saw had come in with multiple spaces and protruding teeth. He had come asking for veneers, but then I thought if I do veneers, he will end up looking like Jim Carrey in the Mask.

I convinced him that he would look silly and he needed orthodontics. I showed him how Invisalign works; he was my first case.

After 9 years and 760 cases of Invisalign I have never looked back. In fact I have done only 3 smile makeovers in that time; 2 were replacing old veneers .

Invisalign

Invisalign as many of you know is a clear aligner system. The parent company is Align Technology and is based in California. They have scanning facilities in Costa Rica, research facilities in USA, UK, Israel, Holland etc. At a recent conference I was informed that Align spent $45,000,000 last year in R&D.

Invisalign is a series of aligners that are planned with computer aided design and scanning (CAD), and created with 3D printing (CAM). Each aligner exerts a small force and the teeth usually move according to plan.

Impressions are taken as 2-stage silicone impressions or you can take digital impressions with the new Itero scanner.

I would like to describe an interesting case of moderate to severe crowding in a class 1.

Invisalign case

Dr KN had just recently qualified as a medical doctor and came in from a recommendation.

He was very quiet, did not smile and wanted his teeth straightened. He did not want to have fixed braces.

Start images

My findings were:

Class 1: collapsed posterior segments: moderate upper, severe lower crowding: centrelines were not coincidental: mild class2 canine RHS.

I agreed that we could try Invisalign as the lower arch was very crowded and that the scans would show if lower extractions were necessary.

The planning was done by me and I wanted to avoid extracting upper premolars because the patient was very conscious of his smile and he did not want prolonged treatment if possible.

Treatment schedule:

The aligners came back as 39 uppers and 29 lowers. The upper arch was expanded and interproximal reduction was carried out at the 2/3rd stages in order to help shift the upper centre line and to

reduce interproximal triangular spaces. Lower first premolars were extracted at the beginning.

I saw the patient every 6-8 weeks for reviews. I checked the aligner fit, attachment activation, contacts and collisions.

Over time his crowding was alleviated and he started to chat and smile more often.

After a period of 18 months we took refinement impressions for minor corrections and closing the extraction spaces. There were 7 refinement aligners in total.

Refinement images

Final images

Things that I did not do

I did not consider class 1 canine positions important because that would have involved removing 2 upper premolars or unnecessary stripping. The lower incisors were not in the midline as that would have involved either LHS molar distalisation and longer treatment, or aggressive stripping LHS and shifting all the lower RHS teeth to the LHS.

Patient was not concerned and was happy with the treatment time.

Conclusion

Orthodontics for a general dentist is always a steep learning curve. It takes about 1 year to see results and you do not really know whether they will be as expected.

Invisalign is a system that is easy to use for the patient, but difficult for the dentist to implement. If you have a non-compliant patient then the results will be less than satisfactory.

But a well planned and well explained treatment using Invisalign with a compliant patient is a new way to do orthodontic treatment.

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