There's a muscle at the corner of your jaw that has been working out every night for years, and nobody ever mentioned it had joined a gym. If you wake up with a tight, aching jaw, or a dull tension at your temples, or you've watched the sides of your face slowly grow squarer, you've already met it.
It's called the masseter, and it's the muscle you clench with. You can find it right now: put two fingers just in front of your ear, bite gently, and the firm ridge that pops out is the one we're talking about.
Why clenching builds the jaw muscle
Muscles do one thing when you work them, which is grow. That's the whole principle a gym is built on, and your jaw doesn't know it's meant to be the exception.
Grinding your teeth in your sleep, which has the medical name bruxism, is a workout by any honest definition. You're pressing one set of teeth against another with real force, night after night, and the masseter is built to press hard; for its size, it's one of the strongest muscles you own. So it does what any worked muscle does. It thickens.
That's why the two complaints arrive together. The jaw aches in the morning because the muscle has been under load all night with no rest, the same way your calves ache the day after a long walk. And the face gradually widens at the bottom because the muscle under the skin there has genuinely got bigger.
How Botox for teeth grinding works
Masseter Botox® is simply an anti-wrinkle injection placed into that jaw muscle instead of into a forehead line. It works by quietening the signal that travels from nerve to muscle: in the forehead it stops the muscle creasing the skin, and in the jaw it takes the power out of the clench.
The muscle isn't switched off, which is the worry almost everyone arrives with. You still chew, you still talk, you still bite into an apple. What goes is the top end of the force, the hard clamping that happens when you're not awake to stop it, so your jaw keeps what it needs for an ordinary day and loses the strength it was only ever using against itself at night.
Then the ache lifts, for a very simple reason: a muscle that stops working all night finally gets to rest, and a rested muscle stops hurting. The tension that spreads up to the temples usually eases with it, because those muscles sit together at the side of your head and share the load. You probably won't catch the day it happens, either. You wake up, and your jaw simply isn't the first thing you notice about the morning.
Does jaw Botox slim your face?
This is the question we're asked most, and the honest answer comes in two halves.
Yes, it can. If the width at the bottom of your face comes from a masseter that clenching has built up, relaxing that muscle lets it settle back toward its natural size, and the corner of the jaw softens with it. Nothing is cut and nothing is removed; the muscle just stops being kept in training.
And no, not always, for reasons that have nothing to do with the treatment working. Some faces are wide at the jaw because of the bone underneath, and no injection changes bone. Other people have a masseter that was an ordinary size to begin with. Then the injections would still ease the clenching, but your face would keep its shape, and you should hear that before you book rather than afterwards.
Working out which one you are is a quick check at a consultation: we feel the muscle while you clench, and its size answers the question. And if you want the clenching gone but your jawline left exactly as it is, do say so, because that's a perfectly good thing to ask for and it changes the plan we agree with you.
What it doesn't do
It takes the force away, which really is most of the problem. What it can't do is undo wear that has already happened, so if years of grinding have flattened or chipped your teeth, those want looking at by your dentist too. The injections protect you from here on; they don't fix the damage that's done.
It also doesn't deal with why you clench. Stress, sleep and habit carry on being themselves. What changes is that they no longer have a fully powered jaw to work with, and that's the difference between having the habit and paying for it every morning.
The appointment, and when it settles in
A consultation always comes first, because we need to check the treatment suits you and agree what you want from it. The treatment itself is short: a few small injections into the muscle on each side, no anaesthetic needed, any discomfort brief and minimal, and you're typically done in about fifteen minutes. You leave with aftercare for the first hours and days, then carry on with your afternoon, because there's very little here to recover from.
The two effects arrive on different timetables, and it helps to know that so you're not checking the mirror too early. The easing of the clenching and the ache builds over about ten days, as the muscle properly relaxes. The slimming, if that's what you came for, comes on far more slowly, because a muscle that stops being worked shrinks a little at a time. It's the same slow fade you'd see in your arms if you stopped lifting, which is exactly why it looks natural.
It isn't permanent either, because the muscle steadily regains its strength, and the clenching returns with it if the habit is still there. So we'll recommend a review appointment to look at your result together, and you can decide from there whether you want it again.
Bring the morning ache to a consultation
If you've read this far with a hand resting on your jaw, that's your answer about whether to ask. Arrange a consultation and bring the ache with you: we'll feel the muscle, tell you plainly whether it's built up or not, and explain what the injections would and wouldn't change for your face. Every treatment at Broadway Retreat is delivered by experienced medical professionals at our CQC-registered clinic in Manchester, and nothing goes ahead until you decide.
Most people have never once thought about the masseter. Then they spend their mornings happily noticing that it doesn't hurt.