Teeth grinding and jaw tension: how masseter treatment can help.

Teeth grinding and clenching, known as bruxism, is surprisingly common, and many people have no idea they do it. It can happen while you sleep, when you have no control over it, or during the day, often as a habit of clenching when you're concentrating, stressed or busy.

Either way, the muscle doing most of the work is the masseter: a thick, powerful muscle at the angle of your jaw that you use to chew. Rest your fingertips on the angle of your jaw, a little in front of your earlobes, and clench your teeth: you'll feel it tighten.

When it's overworked night after night, that strength works against you. Constant grinding and clenching can leave the jaw tired and sore and wear down your teeth, and over time it can enlarge the muscle itself, giving the lower face a squarer look.

• A tired, aching or tight jaw, especially when you wake up
• Headaches first thing in the morning, often around the temples
• Teeth that look worn, flattened or chipped, or feel more sensitive
• A partner who hears you grinding at night
• Jaw muscles that feel tense, or a jawline that looks squarer than it used to
• Ridges on the inside of your cheeks, or little indents along the edges of your tongue

Grinding is often linked with stress, poor sleep, caffeine and alcohol, but it can happen for many reasons. If any of these sound familiar, it's worth mentioning to your dentist, who can check your teeth for wear.

Masseter treatment uses precise anti-wrinkle injections into the jaw muscle on each side. Rather than smoothing lines, the aim here is to reduce how forcefully the muscle can contract, so it can't clench and grind with the same strength.

For many people that means less tension in the jaw and less pressure on the teeth. And because a muscle that's working less gradually becomes less bulky, regular treatment can also soften a square jawline, bringing the lower face into better balance.

The aim is to calm clenching, not to stop you chewing. Most people eat and talk normally, though some notice that very chewy foods take a little more effort for a while.

• Treatment time10–15 minutes
• ResultsA few weeks; full result at 4–6 weeks
• Lasts3–6 months
• DowntimeNone
• PriceFrom £180

1. 01ConsultationGwen assesses the muscle, asks about grinding, clenching, headaches and jaw pain, and goes through your medical history.
2. 02Skin prepYour jawline is cleansed and the injection points are marked.
3. 03TreatmentA few small injections into each side. It's over in minutes.
4. 04Back to your dayReturn to normal activities straight away. Avoid massaging or pressing on your jaw for 24 hours.

The muscle relaxes gradually, so be patient: most people notice a difference over a few weeks, with the full result a little after that. Regular treatments keep the muscle relaxed, so the benefits last.

Masseter treatment can ease the strain of grinding, but it isn't a substitute for dental care. Keep up your regular check-ups so your dentist can keep an eye on any wear, and ask whether a night guard, a custom mouthguard you wear in bed, might help protect your teeth.

The two can work well together: the guard protects your teeth, while a calmer muscle means less force behind the grinding.

Masseter treatment can suit people who grind or clench, people with jaw tension, and people who'd simply like a softer, slimmer jawline. Men often need additional units for the best result, because their jaw muscles tend to be stronger.

Like other anti-wrinkle treatments, it isn't suitable during pregnancy or breastfeeding, and some medical conditions and medicines can affect whether it's right for you. That's why it always starts with a consultation and a full medical history.

If your main concern is the shape of your jaw rather than grinding, tell Gwen about the look you're hoping for, and she'll explain honestly whether masseter treatment is the best way to get there.