Our bodies deal with stress in different ways. Most of us are aware of the common subconscious signs that we are anxious — low mood, insomnia, losing weight. But there is one sign of stress that may be affecting you without you realising — jaw clenching. If you are experiencing aching facial and shoulder muscles, dizziness, splitting headaches and earache, you might be one of about seven million people affected in the UK. Known as bruxism, it is characterised by involuntary tightening of muscles around the jaw as the teeth clamp together. Without realising it, you could be clenching your jaw as you sleep, work — or even now as you are reading this.

According to the Bruxism Association, sleep disorders, illness and certain medications are all associated with jaw clenching, but stress and anxiety are the biggest underlying causes. The jaw muscles are among the strongest in our bodies and react to mental stress by tightening. Experts report an upsurge in jaw-clenching cases when feelings of frustration, fear or anger bubble beneath the surface. During Donald Trump’s first presidency in 2017, American Vogue announced “Trump-induced jaw clenching” to be a phenomenon, with dentists reporting more patients coming forward with symptoms after the controversial election. And a survey by the American Dental Association in 2020 revealed that more than 70 per cent of dentists had reported an increase in patients experiencing teeth and jaw clenching, caused by the stress of the pandemic.

Helen Cowgill, a physiotherapist who specialises in treating temporomandibular joint (TMJ) issues, including jaw pain and dysfunction caused by clenching, sees a steady stream of clients with the condition at her southwest London clinic. She says that clenching can often be traced back to general life worries. “People with lower-level chronic stress at work or home might be clenching without knowing they are doing it,” Cowgill says. “For others, something small can tip the balance or a traumatic event such as a divorce, death or job loss can seemingly trigger it out of the blue.” But how do you know if you are suffering — and what can you do about it?

• Read more expert advice on healthy living, fitness and wellbeing

The tell-tale signs that you are clenching your jaw

Dr Brandon Nejati, a dental surgeon and founder of the Nejati Clinic, a holistic dental practice in Belgravia, London, says that classic signs of jaw clenching include facial soreness and stiffness, headaches and sometimes clicking or limited movement of the jaw joint. “Tightness and muscle spasms can occur,” he says. “Clenching often goes hand in hand with teeth grinding, although they can occur in isolation, and dentists will often spot the wearing away of tooth enamel if patients press teeth together as they clench their jaw.”

If you have concerns, book a dental appointment. Crowns, fillings that are slightly too high, or the loss of one or more teeth can cause the mouth to close incorrectly which strains the jaw muscles and these can often be easily rectified. “The TMJ needs equal support from both sides of both jaws,” Nejati says. “If the balance is upset in any way it can exacerbate clenching and even subtle changes to your bite might be responsible for added jaw tension.”

Are you making it worse?

Repeatedly chewing gum, biting nails and your bottom lip and even pouting for selfies are all habits that exacerbate jaw-muscle fatigue. “These are what we call parafunctional habits, repetitive behaviours that over-work muscles in the mouth and jaw,” Cowgill says. “We see a lot of tight, tense jaw muscles in people who do these things and also those who are obsessed with building up facial muscles for a defined jawline.

“A lot of people clench their jaw muscles all the time without realising it. Biting your lower lip and fingernails, chewing gum or biting on your front teeth, even excessive yawning will all load the jaw muscles and exacerbate pain.”

Will massage help?

“I have TMJ and wake most days with awful headaches from tension and jaw clenching,” the TV and radio presenter Zoe Ball revealed on Instagram last year, adding that, for her, a lymphatic massage by a therapist helps to ease discomfort from the condition. Cowgill says that a physiotherapist can perform trigger point massage in the area around the TMJ, which is located in front of each of your ears where the skull and jaw meet. She adds that you can also try a DIY facial massage by gently kneading the cheek and jaw muscles with your thumbs and fingertips daily.

Should I try Botox?

Several studies, including a review in Nature journal, have shown that injections of muscle-relaxing Botox into the masseter and temporalis muscles, which close the jaw as it chews and bites, can help to relieve tension associated with bruxism. It should only be considered in consultation with a dentist or jaw specialist. “For some people Botox, or botulinum toxin, does help to reduce clenching,” Nejati says. “In doing so it can also reduce accompanying tension and headaches.”

He adds that Botox can take two weeks to kick in, but the results of a one-time treatment can last three to four months. “It doesn’t last for ever and you will need to have repeated injections every three months or so,” Nejati says.

Are there any exercises I can try?

Philip Bateman, a physiotherapist who specialises in treating TMJ and jaw pain issues, says that “a normal resting jaw position involves keeping upper and lower teeth apart when relaxed and daily exercises can help to achieve this”. One he suggests involves closing your mouth to make sure your teeth are touching but are not clenched. Rest the tip of your tongue on your palate, just behind your upper front teeth, and gently run the tip of your tongue backwards towards the roof and back of your mouth. Hold your tongue back in this position and then slowly open your mouth so that you feel tension in the back of your neck and under your chin. Hold there for five seconds. Relax and repeat for five minutes every day.

• Three ways to ease neck pain

Nejati says that working muscles underneath the chin can help the masseter muscles of the jaw to relax. “Make a fist and place it beneath your chin,” he says. “Push upwards with your fist and try to open your mouth against the resistance. Do this a few times a day.”

Do women suffer more than men?

A recent analysis of 720 people aged 30-89 in the American Journal of Orthodontics and Dentofacial Orthopedics showed that women experience more bruxism. However, according to the Bruxism Association “it is not really known whether there are any distinct gender differences, as some studies have found greater associations in men, others in women and some studies have found no differences at all”.

Cowgill says that, in her experience, some women are more susceptible to jaw clenching at certain times of life. “There’s not much supporting evidence, but we do know that oestrogen plays a role in pain control,” she explains. “When stress levels rise and oestrogen levels drop during the menopause it could lead to worsening jaw clenching or tension.”

Should I wear a mouthguard?

A mouthguard designed to keep upper and lower teeth apart, cushioning them from the force of clenching, and to reduce tension in jaw muscles might be prescribed by a dentist for night-time use. The Bruxism Association has a range on its website. “They need to be hard rather than softer material mouthguards and should be custom-fitted by experts,” Nejati says. “It is very important that they are carefully adjusted to balance the delicate equilibrium of your bite so that clenching and tension are reduced.”