Speaking with aligners: will you lisp?

An aligner puts a thin layer of plastic over your teeth, on the front and on the inside. To make an s or a z, you place the tip of your tongue just behind your upper front teeth and push a narrow stream of air past them. That thin layer sits exactly where that air has to go. Your tongue has to find a new spot, and while it's still searching, your s sounds a bit slushy or less crisp.

Your lips sit slightly differently too. In a study that measured faces in 3D before and after the aligners went in, the position of the lips shifted by up to one and a half millimetres. In that same study, participants reported that their speech sounded different.

In research it's mainly the s and the z that change. Sounds like sh and ch can be harder as well, and the th may trip you up for a while.

Not everyone notices it. In an older questionnaire study of people who had been wearing aligners for a few months, almost half had never had any trouble with their speech.

Sources differ here, so we'll put them side by side.

• For many people it's noticeably better after a few days.
• Align, the company behind Invisalign, says it usually disappears within one or two weeks.
• A review of seven studies came to the same conclusion: most people were speaking normally again after 7 to 14 days. A small group needed 30 to 60 days.
• In one study of adults, speech therapists could still hear a slight difference in the s in some people after two months.

In our practice we see that for most people it's gone within a few days. If it takes you longer, don't worry: as the studies show, that happens too. The authors of that review also call the evidence weak, because many of the studies weren't strongly designed.

What you're really worried about is other people hearing it. That last study says something about this. Six speech therapists listened to recordings of adults reading a text aloud, just after they'd been given their first aligners. About half of their ratings were "normal", and most of the rest "mildly altered". Everyone stayed easy to understand.

That was a strict test: trained ears, a recording to listen to closely, and a recording made right after the aligners went in, before anyone had had a chance to adjust. How ordinary listeners hear it hasn't been studied separately, as far as we could find. We'd rather say that plainly.

What has been asked: in the questionnaire study mentioned above, 93 percent felt not at all held back from speaking after a few months.

As for seeing them: usually they barely can. How little the aligners show is explained on the page about invisible aligners.

Your tongue learns this the way it learns everything: by practising.

• Talk a lot. The more you talk, the faster your mouth gets used to the new feeling.
• Read aloud for a few minutes every day. A newspaper, a book, an email from work.
• Speak a little more slowly and pronounce your words deliberately. That way you notice where your tongue gets stuck.
• Focus on the words that trip you up. Read the agenda for your next meeting out loud, for example, with every s in it.
• Record yourself on your phone once and listen back. You hear your own voice differently from how others hear it, and a recording shows you which sounds aren't right yet.
• Keep your aligners in. Your tongue gets used to the aligner you're wearing, not the one in the case.
• Bring water. Some people have more saliva at first, others a dry mouth. Water is fine with your aligners in and helps with that dry feeling.

Don't make a habit of it. According to Align's instructions for use, aligners in principle only come out for eating, drinking and brushing your teeth. Your wear time of around 22 hours a day still stands, so every quarter of an hour they're out for a meeting comes off the time you have for eating and brushing. Why those hours count so much is explained in do you really have to wear your aligners 22 hours a day?

Is there one moment where it really matters, like a pitch or a job interview? Then you can take them out for that moment. You don't need to check with us first: we trust you to put them straight back in afterwards. Even smarter is not to plan your start right before a day like that. If you can choose, start towards the end of the week. That gives you a few quiet days to practise before work begins again.

Still not much improvement after a few weeks, or is it really bothering you at work? Mention it at your check-up, or contact the practice sooner. You don't have to just put up with it. More questions about daily life with aligners are answered in the frequently asked questions.

Get to know us without obligation. We look at your teeth and think along with you about a good moment to start, even if your diary is full of meetings and calls. Get in touch and we'll book an appointment.