Understanding Teeth Grinding, Jaw Tension & Bruxism
What Is Bruxism? Bruxism is the medical name for two closely related habits: teeth grinding, where the teeth slide against each other, and jaw clenching, where the jaw muscles squeeze the teeth together without movement. Many people do one or both without realising it, and the first clue is often a tight, aching jaw, a dull morning headache or tooth wear spotted at a dental check-up rather than the grinding itself. Day Clenching vs Night Grinding Daytime clenching usually happens while you concentrate: at a screen, in traffic, during a workout.
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PRP London Clinic Medical Team
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Last reviewed: July 28, 2026
What Is Bruxism?
Day Clenching vs Night Grinding
A Doctor-Led Approach to Jaw Clenching
Who Experiences This Condition?
Common in
- •Adults under sustained stress at work or home
- •People with sleep problems, including snoring and sleep apnoea
- •Heavy caffeine drinkers, especially late in the day
- •People taking certain medications, including some antidepressants
- •Those with bite problems or a family history of grinding
Factors Affecting Severity
- •How many hours a day the jaw is clenched, awake and asleep
- •Untreated stress, anxiety or poor sleep
- •Caffeine, alcohol and smoking
- •Natural muscle bulk and bite strength
- •How long the habit has gone unmanaged
How to Stop Grinding Teeth
Most people can meaningfully reduce grinding, though 'cure' is the wrong word for a habit that flares with stress. Work up this ladder:
- Fix the inputs: Cut caffeine after lunch, keep alcohol moderate and build a proper wind-down before bed. Stress and poor sleep are the two biggest drivers.
- Retrain the daytime habit: Check in with your jaw whenever you concentrate. The resting position is lips together, teeth apart, tongue on the roof of the mouth.
- Use simple exercises: Slow jaw stretches and gentle massage over the cheek muscles ease tightness and morning ache.
- See your dentist for a splint: A custom night guard protects the teeth and takes strain off the jaw overnight.
- Escalate to a doctor if the habit wins: Where symptoms continue or the jaw muscles have visibly enlarged, prescription-only options can be discussed at a consultation.
Book a consultation for jaw tension or teeth grinding and our doctors will tell you honestly which rungs you actually need.
Masseter Hypertrophy: When Clenching Changes Your Face Shape
The masseter is the powerful chewing muscle at the angle of the jaw, and like any muscle it grows with exercise. Years of clenching and grinding can work it hard enough to cause masseter hypertrophy: visible enlargement of the muscle that makes the lower face wider. Many people notice the change in photographs before they connect it to their jaw habit.
Signs that clenching is changing your face shape include:
- A square jaw or noticeably wider lower face that was not there a few years ago
- A firm bulge at the angle of the jaw that stands out when you bite down
- A face that looks wider from the front but largely unchanged in profile
People searching for 'jaw slimming' or 'facial slimming' are usually describing exactly this: they want the muscle bulk reduced and the lower face softened. Because the masseter is muscle rather than bone or fat, the right plan starts with confirming that the muscle really is the cause, which is part of our assessment. You can read more about the doctor-led side of this on our dedicated jaw treatment page.
Bruxism Treatment Options
Bruxism treatment splits into what dentists do and what doctors do, and honest advice starts with knowing which you need:
- Dentists protect the teeth and correct the bite: custom splints and night guards, repair of worn or chipped teeth, and orthodontic work where a misaligned bite is feeding the habit.
- Doctors assess the muscle and the habit: examining the jaw, ruling out other causes of pain, and, where appropriate, prescription-only options that are only ever discussed and planned at a face-to-face consultation.
Many people need both: a splint to protect the teeth at night and a medical plan for the muscle itself. Neither route is about masking symptoms; the aim is less strain on the jaw, fewer headaches and, where the muscle has enlarged, a gradual return to a slimmer lower face.
Book a consultation and we will map out which side of that split your symptoms need.
Real Patient Outcomes
The image below shows a real patient outcome from a personalised jaw treatment plan at our London clinic. The before photograph is on the left and the after photograph is on the right, taken under consistent framing and lighting.
Results shown follow an individualised course of treatment planned after a medical consultation. Book a consultation for your jaw concerns to find out what a realistic outcome looks like for you.
When to See a Dentist or GP
Grinding and clenching are common and usually manageable, but some symptoms need a dentist or GP rather than an aesthetic clinic:
- Jaw clicking or popping that is new, painful or getting worse
- Pain on one side of the jaw, which needs a proper dental assessment
- Jaw locking, where the mouth will not fully open or close
- Broken, cracked or rapidly wearing teeth, which need repair before anything else
- Facial pain with fever or swelling, which is never a grinding problem
These can point to temporomandibular joint (TMJ) disorders, dental damage or infection, all of which sit with your dentist or GP first. Once the teeth and joint are looked after, we are happy to assess the muscular side of the problem.
Treatment Process
There is no single fix for grinding and clenching; the honest ladder runs from free habits to doctor-led care:
1. Stress and sleep foundations: Lower caffeine, wind down properly before bed and deal with the stress that drives the habit. For many people this alone reduces grinding noticeably.
2. Jaw awareness and relaxation: Notice daytime clenching (lips together, teeth apart is the resting position) and use simple jaw relaxation and stretching exercises.
3. A night guard or splint: Fitted by a dentist, a splint protects the teeth from night grinding and can ease morning jaw ache, though it does not stop the habit itself.
4. Doctor-led options: Where clenching persists or the masseter has visibly enlarged, prescription-only options exist that your doctor can assess and discuss with you at a consultation.
Diagnosis & Assessment
Your consultation starts with a physical assessment of the jaw. We feel the masseter muscle at rest and while you bite down, look at how wide the lower face has become, and ask about headaches, tooth wear, sleep and stress. This tells us whether your symptoms are driven mainly by the habit, by an enlarged muscle, or both, and whether you also need a dentist involved for a splint, a bite assessment or tooth repair.
Prevention & Management
Lifestyle Tips
- •Deal with stress actively, it is the single biggest driver of grinding and clenching
- •Cut caffeine after midday and keep alcohol moderate
- •Protect your sleep: regular hours, a wind-down routine and a dark, quiet room
- •If you snore heavily or wake unrefreshed, ask your GP about sleep apnoea
Home Care
- •Train the daytime resting position: lips together, teeth apart, tongue on the palate
- •Use warmth and gentle massage over tired jaw muscles in the evening
- •Do slow jaw stretches rather than chewing gum, which works the muscle harder
- •Wear your splint or night guard every night if your dentist has fitted one
Symptoms & Causes
Common Symptoms
- Jaw tension or tightness, especially first thing in the morning
- Aching or tenderness over the masseter muscle at the corner of the jaw
- Dull morning headaches, often around the temples
- Teeth that look worn, flattened or chipped, often first noticed by your dentist
- Aching or tired jaw muscles when chewing
- A square jaw or wider lower face that has developed gradually
Potential Causes
- Stress and anxiety, the most common trigger for both day clenching and night grinding
- Sleep problems, including snoring, sleep apnoea and disrupted or poor-quality sleep
- High caffeine intake, especially later in the day
- Bite problems, such as misaligned, crowded or missing teeth
- Side-effects of some medications, including certain antidepressants
- Alcohol, smoking and recreational stimulants, which all increase grinding activity
Treatment Options at PRP London
Anti-Wrinkle Treatment (Jaw & Masseter)
Doctor-led, prescription-only care for masseter-related jaw widening and grinding. Options, dosing and suitability are always confirmed at a face-to-face consultation.
Learn moreFrequently Asked Questions
Start with the drivers: reduce stress where you can, cut caffeine after lunch, limit alcohol and protect your sleep. During the day, train the resting position of lips together, teeth apart. If grinding continues at night, ask your dentist about a custom splint, and if symptoms persist or your jaw muscles have enlarged, a doctor can assess you and discuss prescription-only options at a consultation.
Stress and anxiety are the most common reasons, followed by poor or disrupted sleep, high caffeine intake and some medications, including certain antidepressants. Bite problems such as misaligned teeth can also contribute. Often several of these stack up at once, which is why a stressful period so often shows up in your jaw.
There is no permanent cure, because grinding is a habit that tends to flare whenever stress or poor sleep returns. It can be managed very well, though: most people get meaningful relief from a combination of stress management, better sleep, a dental splint and, where needed, doctor-led care for the muscle itself.
Masseter hypertrophy is muscle growth from overuse. Chronic clenching and grinding can work the muscle for hours a day, and like any muscle trained that hard it gets bigger. Genetics, a strong natural bite and frequent gum chewing can all contribute. The result is a firmer, bulkier muscle at the angle of the jaw and a wider lower face.
First reduce the workload: manage the clenching habit and wear a splint if you grind at night. A muscle that is worked less gradually loses some bulk on its own, though this is slow. Where the enlargement bothers you cosmetically, often described as a wish for jaw slimming or facial slimming, prescription-only options exist that reduce the muscle's workload directly; a doctor can assess whether they are appropriate for you at a consultation.
Short term: apply warmth over the sore muscles, massage them gently, stick to softer foods for a few days and use slow jaw stretches. Then address the cause, with daytime habit retraining and a night splint from your dentist if you grind in your sleep. Pain that is one-sided, worsening or accompanied by clicking or locking should be assessed by a dentist or GP.
There is no daily pill that treats it. Splints, stress management and sleep improvements are the first-line approach, and a short course of simple pain relief can help during a flare. Where the habit or the muscle enlargement persists, prescription-only options exist that a doctor can assess and discuss with you at a face-to-face consultation.
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