Pain with aligners: what's normal and what isn't?

An aligner pushes your teeth a small step further each time. You feel that push, especially in the first days with a new aligner. Most people describe it as tightness, as if your teeth are being gently held all day long.

You may also notice this:

• Your teeth feel tender when you bite or chew.
• Your teeth feel slightly looser when you take the aligner out. That can be part of it too, as long as they're on the move.
• An edge of the aligner or an attachment rubs against your lip, cheek or gums.

That last one isn't pressure, it's rubbing, and that's a different story. More on that further down.

A new aligner is made for the position your teeth are heading to, not the position they're in now. That's why it feels tighter on the first day and sometimes takes a little more effort to click into place. Small differences between the aligner and your teeth are normal. Your teeth just need some time to shift into that new position.

Around the root of every tooth there's a thin layer of tissue that holds the tooth in the bone. When the tooth is pushed, that tissue gets squeezed on one side and a temporary inflammatory response follows. That makes your teeth more sensitive. The response is at its strongest after about a day and then settles, which is why the feeling eases after a few days.

For most people, pressure. Align, the company behind Invisalign, says people usually describe it as "pressure". In an older study of 54 people who were a few months into treatment, just over a third had no pain and just over half had mild pain. A small group had more trouble.

It can turn out differently, though. Another study in adults found that people with aligners actually reported quite a bit of pain in the first few days. How it goes for you, you'll only know once you start. What one person barely notices, another finds really unpleasant for the first days. In the study of 54 people, almost half had some difficulty chewing at some point, mostly because their teeth were sensitive to pressure.

The first day is usually the hardest. A recent review of 34 studies on the side effects of aligners found this pattern: pain peaks within 24 hours, eases around day three and is minimal after a week.

With every new aligner the pressure can come back. According to Align's instructions for use, that lasts a few days and then gradually fades. In a study where people recorded their discomfort every day, discomfort after later steps was consistently lower than at the very start. So the first aligner is usually the toughest one.

There's no trick that makes the pressure disappear completely. You can make it easier on yourself, though.

• Eat something softer on the first day. For many people, chewing is when they feel it most.
• Keep your aligners in. Ordinary pressure is no reason to leave them out longer, because your teeth only move while they're in. Your wear time stays at around 22 hours a day. Why that matters so much is explained in do you really have to wear your aligners 22 hours a day?
• If the pressure gets in the way of work or sleep, an ordinary painkiller can help. Read the patient leaflet first, stick to what it says, and ask your pharmacist or GP if you're not sure it suits you.
• Is an edge rubbing? Don't wait until you have a sore spot. Ask the practice what you can do.

Pressure that gets a little less each day is part of it. Get in touch with the practice if:

• the pain doesn't ease after a few days, or gets worse
• a new aligner clearly doesn't fit properly
• an attachment has come loose or broken off
• an edge keeps rubbing or causes a spot that won't settle
• you're unsure whether something is still normal

Do you feel sharp pain, or so much discomfort that you can't keep going? Put your previous aligner back in and get in touch with the practice straight away.

Very rarely, someone has an allergic reaction to the material. If you notice swelling or another strong reaction after putting your aligners in, take them out and seek medical help right away.

For everything else: you don't have to wait until your next check-up. Better to ask once too often than to walk around for a week with something that isn't right. More practical questions about treatment are answered in the frequently asked questions.

That's a good question to ask before you start. Get to know us without obligation. We look at your teeth and tell you honestly what to expect in the first weeks, including the less pleasant side. Get in touch and we'll book an appointment.