Invisalign: Much more than you wanted to know

It's January 2024 and what better topic to start the new year than orthodontics.

One ordinary day, at a regular check-up, my dentist noticed that there was some concerning movement in my lateral mandibular incisor (a tooth on the bottom right jaw near the front). The tooth was leaning back slowly, deeper into my mouth. As the tooth leaned further and further back the gum line would fall lower and lower, exposing its root and causing decay. Therefore, we needed to pull the tooth back into place.

There are a few ways to go about that. However, for me the only real option was Invisalign - a series of hard plastic trays that incrementally pull your teeth closer to perfect alignment. Other companies like Byte offer similar, hard plastic tray based treatment, but I got Invisalign so I'm going to tell you about Invisalign.

Invisalign is a pricey and complex procedure you can read about online, but relatively little in the way of first-hand patient accounts. If you are considering this sort of treatment then here's what I wish I knew from the start and questions you should ask before you begin. Obviously, this is not medical advice, it's merely context to help you ask better questions. Consult a professional if you're considering treatment.

The number one thing is to go to a dentist you trust. There are a lot of practices who put the hard sell on you to start Invisalign. Some dentists may try to upgrade you to a package you don't need - for example, to align otherwise healthy teeth for aesthetics. If you feel pressured to undergo the procedure, or to add additional treatments you don't need, then consider going to another dentist. While I'm very happy with my dentist, a friend had a horrible experience where important details were not explained to them. If you trust your regular dentist, then probably stick with them if they offer Invisalign.

If you need to find a trusted dentist, then go to at least three and pick the one who best answers your questions. Tell these dentists in the first appointment what objectives are in-scope and out-of-scope. For example, I told mine that I wanted to prevent future decay, but aesthetics were out-of-scope, so don't give me extra trays just to make the teeth look nice. You might tell your dentist that making it easier to floss is in-scope, but improving bite is out-of-scope. It depends what you want to achieve. What matters is that you set clear expectations.

Questions to ask your dentist

How will you make room for the teeth to move?

There's basically three ways that Invisalign can make room for your ideal alignment: enamel shaving, extraction and movement. If the dentist you see doesn't inform you of these techniques in detail, then find another dentist.

• Enamel shaving, which removes around 0.25 millimeters of the 1-to-1.5 millimeters of enamel we all have on our teeth. Enamel cannot grow back, so this is permanent. My dentist described the shaving as neither painful nor ugly, but after you complete Invisalign you will need to use fluoride toothpaste to strengthen the teeth and see your dentist regularly to monitor for decay, as your teeth will no longer be as well protected.
• Extraction, which removes a whole tooth to give those remaining teeth more room to move. The tooth in question is usually extracted from further back in the mouth where it's not noticeable. This procedure is a little more drastic than enamel shaving.
• Movement, which simply pushes all the teeth around. Often your teeth need to go out and then back into place - so you will 'overshoot' your alignment at first. Excessive movement can weaken the roots of the teeth, so good dentists will keep this to a minimum. Movement can be less comfortable during treatment and may take longer because you may need to move your stubborn molars.

I only needed moderate movement for my treatment. While my top teeth were already well aligned, they may have needed Invisalign to get out of the way of the bottom teeth while they moved. I wasn't keen on this because my top teeth had already moved a lot when I had braces as a teenager. But I got lucky. My dentist sent my scans to Invisalign and found that we could move just the bottom jaw without needing to re-align the top teeth.

What do I need to do while I undergo treatment?

For one, you need to wear your trays for at least 22 hours every day! You need to wear the trays all the time unless you're eating or drinking. A friend of a friend said they only wore the trays ~18 hours a day and their treatment plan had to be extended from 12 months to 18 months because their teeth weren't moving enough.

I found the discomfort of putting the tray back in increased exponentially the longer I left it out. It was better to take the trays out for a couple of short periods than to remove them for one long meal. If in doubt, put your tray back on.

Each new tray will start out quite hard and you need to chew a rubber stopper to fit them snugly over your teeth. After a day or two they soften and become easier to get on. After about two-weeks the trays can get so soft that they lose their efficacy, but it depends on your tray.

You will need to be very diligent about brushing your teeth and flossing. You will also need to see your dentist regularly to check progress and receive new trays.

How do I eat or drink?

You cannot eat or drink while wearing the trays - except for water, water is fine anytime. You need to brush your teeth and your tray before you put the trays back in, otherwise food and drink gets trapped and accelerates decay.

I found it helpful to carry a small toothbrush and toothpaste around with me. Get a brush with very stiff bristles because plaque will build up on the tray and you need a stiff toothbrush to get it off. You need to brush and floss thoroughly because trapped food is particularly damaging if it's incubated under a tray.

Wearing Invisalign can increase or decrease your weight depending on how you behave. I found that I simply did not snack at all wearing Invisalign, it was never worth the hassle of taking my trays out and brushing my teeth to put them back in. However, I did eat larger meals out of fear that I'd feel hungry before I took my tray out again. So Invisalign could help you lose weight by eliminating snacks, if you have good discipline about what you eat when you do eat.

The hardest part for me was coffee. I used to drink full cups of coffee, but I switched to espresso. It was easier to down the shot then immediately brush my teeth and trays. You may want to switch to espresso while you're on Invisalign.

How long will it take?

Depends on the plan. You wear the tray for one week then switch to the next tray. My plan included 21 trays which meant 21 weeks - in theory. If you don't wear the trays enough, you'll take longer. If you can't see your dentist on time, you'll take longer. If your final bite comes out wonky, you'll take longer.

During the last 4 weeks of my plan, I was overseas so I couldn't get a retainer fitted right away. To stop my teeth moving back over that period, my dentist instructed me to wear the last few trays for two weeks each instead of the usual one week. It's not a good idea to wear a tray longer than two weeks because the tray softens and becomes less effective. I spaced out my last few trays enough to finish my holiday, go the the dentist and get my retainer.

Do not throw out your old trays. At least wait until you've got your post-treatment retainer. Sometimes the last tray overshoots the ideal alignment or the final bite isn't satisfactory, so you'll want to put the second or third to last tray back in and return to that alignment. If you think you're done with a tray, give it a good thorough clean then put it back in the labelled package it came in.

How much does it hurt?

I didn't experience much pain. I found the first tray quite uncomfortable for 36 hours, then it wasn't uncomfortable at all. The tray softens slightly as you wear it. Subsequent trays only hurt for about 12 hours after I started them. Avoid tough or hard foods because your teeth will feel wobblier when you have the trays out.

I highly recommend switching to a new tray in the morning. Take some painkillers if you need to. Your teeth will ache as they move into place which makes it hard to sleep - so try to get the aches out of the way during daylight hours.

One unexpected pain was taking the trays out. The trays fit the teeth very tightly, and your finger nails may get sore pulling the trays off. Invisalign packages include a plastic hook for leveraging the trays off - I suggest you use it.

New trays can be, quite literally, rough around the edges and can cut up your gums. Use a small file to sand off the edges of a new tray if they feel uncomfortable. However, don't go overboard, those trays are expensive.

How much will it cost?

This depends on your dentist, country and whether the Invisalign patent has expired by the time you're reading this. The price includes Invisalign's standard fee plus your dentist's fees and services on top of this. I got mine done in Singapore in 2023 which entails one set of prices. Your dentist will offer another set. Ask to see the pricing option guide.

Invisalign offers tiered packages. Minor corrections can get a lower tier, but significant movement will need a higher tier. The lowest tier I could choose from was $3,500 SGD and the highest was $6,500 SGD for a comprehensive plan. The down-payment was $2,000 SGD to enter my scans into the Invisalign system. Replacing lost trays will cost extra.

On top of this your dentist will add fees and services. These usually include the price a consultation appointment, scaling and polishing before they scan your teeth, etc. Some dentists will suggest add-ons like teeth whitening for when you're finished.

What do I need to do after I finish?

Once you're finished it's recommended to wear a retainer for 2-5 years to stop the teeth drifting back out of alignment. Your teeth have gone on a wild ride and your mouth needs time to consolidate (i.e. stop the teeth wobbling). You will typically need to wear a retainer, similar to an Invisalign tray, for 22 hours a day to keep your teeth in place. Eventually you will switch to wearing the retainer at night only. However, if you grind your teeth the retainer may not be best for you or needs to be made of stronger stuff.

If you are so inclined, some retainers can be designed to facilitate at home teeth whitening. Discuss this with your dentist before you begin treatment so they know to factor it into your plan.

You can also get a wire that's glued to the backs of your teeth. The wire prevents your teeth from moving by binding them together in support of each other. However, you'll need to be careful how you floss because there are more places for food to get caught. You'll need to see your dentist more regularly - around once every four months - to properly clean the wire. A wire can make it harder to whiten your teeth, depending on the wire. And a wire alone may be insufficient to keep all your teeth in place.

In my case, I got a wire and a retainer. I didn't want to wear the retainer for 22 hours a day, which meant I needed a wire to keep my teeth in place. However, a wire alone wouldn't keep my teeth in place, so I needed to wear a retainer over my teeth (and the wire) every night. I'm still going through the wire + retainer combo, and I'll write more when it's over.

That's it. That is everything which I, a medically untrained lay-participant, has learnt and wished I knew going into Invisalign. If you are considering a similar procedure, I urge you to be clear with your dentist why you're doing it, and to ask them:

• How will you make room for the teeth to move?
• What do I need to do while I undergo treatment?
• How do I eat or drink?
• How long will it take?
• How much does it hurt?
• How much will it cost?
• What do I need to do after I finish?

Looking back, I would go through the treatment again without hesitation. I was helped immensely by my friends who shared their experiences. If you are considering a similar procedure, I hope that these reflections might help you too.