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Correcting overjets

“Orthodontics is a speciality that is taught very little at the undergraduate level. Students get a few lectures and learn how to make a removable acrylic appliance, and perhaps they may even get to treat a few simple cases. The majority of teaching is done at post graduate level.

I studied at Guys Hospital, we were taught comprehensively the structure of the tooth, crown and veneer preparation and dental materials. I qualified in 1989 at the time of no prior approval. One of my first patients had severely proclined but healthy teeth. I prescribed orthodontics or crowns but the patient opted for a quick fix. I still remember how I decoronated 6 upper anterior teeth, root filled them and post prepped them all in one sitting (this was certainly not minimally invasive dentistry). Tapered metal cast posts and porcelain bonded crowns were prescribed and fitted. Twenty-three years later the teeth are stable and nothing has failed…”

This is an excerpt from an article I wrote for the July 2013 issue of The Dentist Magazine.

Click here to view a PDF with the full article.

Change With A Smile

presentation1

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.

When can I use Invisalign for a patient living in another country?

Orthodontics is the art of moving teeth to a place of patient satisfaction. We do not cut, trim, mask or cover teeth to get this desired position. We have to use our skills as dentists to propose a series of tooth movements and the teeth must follow.
Tooth movement does not always go to plan and that is why it is imperative that the patient attends regularly for review of treatment.
About 18 months ago a couple turned up and the groom wanted his teeth straightened. The problem was that he was leaving in the next weeks for India and would not be back for 12-16 months.
He had:
upper centre line was off to the right
upper and lower crowding
upper lateral incisor was in a crossbite and not visible on smiling
So I examined the patient and assessed his condition and with some trepidation, agreed to provide Invisalign.
Invisalign is a series of clear aligners that are changed in a series every 2 weeks creating orthodontic movements.
Invisalign also needs some interproximal spaces and composite attachments
that are usually done after the scanning and planning process.
But the patient was leaving soon and could not come back when the aligners were here.
So I had to give him attachments and make spaces.
Attachments are usually put on after the aligners arrive as the box contains a template for the attachment process.
So at day 1 I improvised.
I had a patient case unused with an attachment template and used it to place attachments where I deemed them necessary.
I also carried out some interproximal spacing where I thought necessary.
I then took the impressions.
It is very unusual to start a case with attachments already on, but Invisalign did not notice.
I viewed the scans and agreed with the movements.
I stipulated that there should be no more spacing/dentist intervention until the end.
The braces arrived and the patient paid for them to be delivered to India.
BUT customs got hold of them and wanted money.
They were held up in customs for 2 months before the patient got hold of them.
During the treatment he sent me some pictures of the aligners in the mouth.
18 months he came back and WOW
the teeth were exactly as the scan and I had predicted.
He had some cleaning to do and very little else. But to get his moneys worth he wanted a little more pushing out of the aligner…cheeky bugger.
Anyway enjoy the picture of Invisalign 18 months in 1 visit



My teeth are so good that I forgot how bad they were

My teeth are so good that I forgot how bad they were

This lady had complained of anterior crowding and had already had orthodontic treatment. Her main complaint were the 2 severely overlapped upper incisors.

We assessed her scans and decided against extractions. The arches were expanded, the lower teeth pushed down and out into a wider arc.

The biggest problem we had was the overlap of her central and lateral incisor. Due to this overcrowding, the gum tissue had never developed or was deficient. So when we straightened the teeth, we had a soft tissue triangular space.

We had to reshape the sides of the 2 teeth to be less triangular and to allow Invisalign to bring the teeth together.

It took over 2 years to finish, because the patient became obsessed with these 2 teeth and had actually forgotten how crowded she was initially.

We spent about 9 months just refining the 2 upper incisors.

I was happy with the result but the patient had forgotten the beginning until I showed her the original photos. She then agreed with me, but she never wrote a testimonial.

See for your self.

 

Invisalign to widen the arch and instil confidence

How to widen the arch and instil confidence without metal braces

 

Miss SM was a very shy person and could not really afford Invisalign. But she hated her smile and had absolutely no confidence.  She hated that her front tooth was sticking out so much.

She had moderate crowding with a narrow high upper arch, which compressed her dental arch leading to overcrowding.

She wanted to know if I could treat her with Invisalign, and I said yes.

My aim was to use the Invisalign aligners in a sequence to gently push out the dental arch and create spaces for her front teeth.

We took did not take any upper teeth out and we started Invisalign.

Even though she did not come as regular as I had hoped, I could start to see a change in her confidence. She was more talkative and open.

We are at the end of the initial set of Invisalign aligners and she is getting married soon. We will continue with refinements afterwards.

You can see a nearly perfect rounded arch form that needs some slight refinement.

 

Invisalign; when to take a tooth out

Dental crowding is an issue of too many teeth and not enough space.

Why is that?

Are we normally born with too many teeth? The answer is No! What has happened is that the size of our dental arch is either developing into a smaller arc, or our dental arch is being constricted.

The latter is usually the case. As we stress over our studies, partners, work and health, we tend to clench and grind our teeth.

The action of our chewing muscles on the teeth causes movement inwards and constriction, leading to dental crowding.

So with Invisalign I usually expand the dental arch to create space, but not always.

Sometimes it is easier to take out the offending tooth and then straighten the teeth

See below, a severely crowded lower arch, corrected by Forma with Invisalign in just over 10 months. The outer tooth was removed first and Invisalign worn night and day.