Margot Robbie Said She Wore Two Dental Appliances at Night, and They Did Different Jobs

Back in March 2018, while promoting Peter Rabbit, Margot opened up about her night-time dental kit in an interview with the Daily Mail. As NewBeauty reported, she said:

"This is so embarrassing, I actually have two retainers, one for my bottom teeth which is for grinding my teeth, and one for my top teeth which is just so my teeth don't move."

She also admitted that wearing her retainer at night "kind of gives me a bit of a lisp". Which is very relatable to anyone who's ever tried to say "sausages" with a retainer in.

That's what's on the record, also reported by Business Standard. It doesn't tell us what treatment she'd had before, how long she'd been wearing them, or anything about veneers or cosmetic work. So I'm not going to guess. What it does give us is a perfect example of two appliances that look alike but do completely different things.

Here's the thing. If you put a clear retainer and a clear night guard side by side on a bathroom shelf, plenty of people wouldn't be able to tell them apart. Both are usually custom-made, both are often clear plastic, and both get worn at night. But that's where the similarity ends.

A retainer is about position. Its job is to hold your teeth exactly where they are, usually after braces or aligners have moved them. It stops them drifting back.

A night guard (also called a mouth guard or splint) is about protection. Its job is to sit between your top and bottom teeth while you sleep, so if you grind or clench, you're grinding plastic rather than enamel.

Think of it like this. A retainer is a seatbelt for your teeth: it keeps them in place. A night guard is a crash helmet: it takes the impact so your teeth don't have to.

You wouldn't expect your seatbelt to protect your head. And you can't always expect a retainer to cope with heavy grinding, or a night guard to stop your teeth moving.

If you've ever had braces or aligners, this is the bit I most want you to remember. The end of treatment isn't really the end.

The British Orthodontic Society says teeth tend to return to where they came from once treatment finishes, and that it can take at least a year for the bone and gums to settle. Its advice is long-term retention, and it notes that lifelong wear may be needed if you want your teeth to stay in their new place.

That's not just a teenage thing either. Teeth naturally shift a little throughout adult life. Plenty of adults who had braces as teenagers notice their teeth creeping back in their twenties and thirties, especially if the retainer ended up in a drawer.

If that's you, don't panic. It's very common, and straightening teeth as an adult is completely possible, often with clear aligners like Invisalign. Just remember the retainer afterwards this time. Even Tom Cruise wore braces at 39, and the same rule applies to him.

Teeth grinding, or bruxism if you want the technical term, is incredibly common, and lots of people do it in their sleep without knowing.

The NHS lists signs like:

• jaw pain
• worn or broken teeth
• headaches
• earache
• disturbed sleep

Often, the first person to notice is your partner, because they can hear it. Or a dentist spots flattened, worn-down edges on your teeth at a check-up.

The NHS says it's not always clear why people grind, but stress and anxiety are the most common links, and sleep problems such as snoring and sleep apnoea can contribute too.

A dentist may fit a mouth guard or splint to wear at night. The NHS is clear that these protect your teeth from damage. They don't cure the grinding itself. So if stress is behind it, tackling the stress matters too.

Grinding can also cause cracked teeth, little surface craze lines and sensitive teeth as enamel wears away. And if you've had cosmetic work, it's one of the most common reasons veneers and bonding chip or come loose.

This is the clever bit of Margot's routine. She had two separate appliances because she had two separate problems: teeth that needed holding still, and grinding that needed protecting against.

A thin clear retainer is designed to hug your teeth closely and stop movement. It's not usually designed to take heavy grinding forces night after night. If you grind hard on it, it can wear, crack or split, and then it stops doing its retaining job properly too.

A night guard, on the other hand, is designed to take that grinding. But depending on how it's made, it isn't always designed to hold every tooth precisely in place.

Sometimes, one appliance can be designed to help with both, but that's a decision for your dentist, based on your teeth, your bite and how heavily you grind. What I'd never recommend is assuming your old retainer is "basically a mouth guard" and grinding through it.

Whether it's a retainer or a night guard, ask your dentist to have a look if:

• it's cracked, split or has holes worn through it
• it no longer fits snugly, or feels tight and painful
• you've noticed your teeth moving even though you wear it
• you're waking up with a sore jaw or headaches
• it's very old, discoloured or smells, even after cleaning

Bring it along to your next check-up. It takes seconds to check, and it's much cheaper to replace an appliance than to fix a cracked tooth or redo orthodontic treatment.

A few simple habits keep retainers and night guards working properly:

• Clean it every morning with a soft toothbrush and cool water. Hot water can warp plastic.
• Brush your teeth before putting it in. Otherwise you're sealing food and bacteria against your teeth all night.
• Keep it in its case. Not wrapped in a napkin, where it's guaranteed to end up in the bin. And definitely not anywhere the dog can reach.
• Don't wear it while eating unless your dentist says otherwise.

Did Margot Robbie wear a retainer? Yes. In 2018, she said she wore two: one on her top teeth to stop them moving, and one on her bottom teeth for grinding.

What's the difference between a retainer and a night guard? A retainer holds teeth in position after orthodontic treatment. A night guard protects teeth from damage caused by grinding.

Can a retainer protect against teeth grinding? Not reliably. Thin retainers can crack or wear if you grind heavily. Your dentist can advise whether you need a separate night guard.

Do I need to wear my retainer forever? The British Orthodontic Society recommends long-term retention, and notes lifelong wear may be needed to keep teeth in place.

Margot Robbie's bedtime routine might not be the most glamorous thing about her, but it's one of the most sensible. Two problems, two appliances, two different jobs.

If you've got a retainer, keep wearing it. If you grind, get it checked. And if you're not sure which one you've got, or whether it's still doing its job, bring it to your dentist. Your teeth will thank you, even if your partner has to put up with a bit of a lisp.

This article is general information based on public reporting. It is not personal dental advice. Margot Robbie and Neighbours have no connection with this article.