Did you ever wonder if your jaw movement falls within the normal range? The typical opening range should be approximately 45mm, or roughly the width of three fingers placed sideways in your mouth.
Range of motion is a good predictor of pain, and our team at the Headache, Neck, and Jaw Clinic sees how restricted jaw movements create compensatory actions that quickly lead to pain. A jaw opening restricted to below 35mm likely causes you discomfort during daily activities like eating and speaking.
To help you spot potential problems early, we’ll show you what makes up your jaw’s normal range of motion and help you understand why these measurements play a significant role in predicting and treating jaw pain.
What is Normal Jaw Range of Motion?
Understanding your jaw’s normal range of motion helps you spot problems before they cause pain.
Typical ranges
The temporomandibular joint (TMJ) is a complex structure that allows your jaw to move.
- Vertical opening (depression): Most people can open their mouth 45-55mm wide, with men’s jaw opening tending to be wider than women’s.
- Lateral movement: Your jaw should move 8-12mm to each side. This side-to-side motion plays a vital role in chewing.
- Protrusion: Your jaw should move forward 7-12mm.
How to measure jaw range of motion at home
You can check your jaw movement easily at home. Stand in front of a mirror and place three stacked fingers between your upper and lower teeth. Normal opening should allow at least three finger-widths between teeth, and any pain and clicking or popping sounds could indicate TMJ issues.
Keep in mind this is just an informal screening tool, and you should always consult a healthcare professional for proper diagnosis and treatment.
What counts as functional jaw movement
Your jaw needs a minimum range to handle daily tasks like eating and speaking. Our experience at the Headache, Neck, and Jaw Clinic shows that a 35mm opening lets patients handle most daily activities, but you might start to notice real limitations if you can’t open this wide.
Limited motion falls into these categories:
- Mild restriction: 30-40mm (2-3 fingers)
- Moderate restriction: 15-30mm (1-2 fingers)
- Severe restriction: less than 15mm (less than 1 finger)
A healthy TMJ should work smoothly and quietly. Joint sounds or vibrations during movement often point to dysfunction. That’s why our jaw pain specialists look at both range and quality of movement when diagnosing TMJ disorders.
How Jaw Range of Motion Predicts Pain
| Range of Motion (ROM) | Expectation |
| <30mm | pain at rest |
| Between 30mm and 36mm | pain on use |
| Between 36- 42mm | mostly pain free with pain on exertion |
| >42mm | pain free |
Jaw mobility and pain levels are closely connected, giving us a clear path to diagnosing and treating your jaw pain.
Pain at rest: <30mm opening
A jaw opening less than 30mm shows signs of dysfunction. You might feel pain even when you’re not moving your jaw, and daily activities become hard to do. You could be waking up with pain that stays throughout the day.
Pain on use: 30–36mm
Jaw openings between 30-36mm usually mean pain starts when you use your jaw. You might feel fine while resting but feel pain as soon as you speak, yawn, or eat. Your body will try to compensate, putting extra stress on nearby muscles and nerves.
Pain on exertion: 36–42mm
With 36-42mm openings, you should be able to handle normal daily tasks, but you may feel pain during demanding activities. Eating chewy foods, talking for long periods, or yawning wide can trigger discomfort. Pain comes and goes rather than staying constant.
Pain-free range: >42mm
Doctors call 40-60mm the sweet spot for healthy jaw movement, and patients who can open their mouth 45-50mm without pain rarely have any issues with function or discomfort.
Hypermobility
It might seem better to have a wider range, but too much mobility can also lead to pain. Hypermobile joints can dislocate easily if muscles aren’t strong enough to control them.
What Causes Limited or Painful Jaw Movement?
Your jaw’s normal range of motion can face restrictions from several root causes that lead to pain during everyday activities. When you come to us, we’ll take the time to help you get a full picture of these common causes to create targeted treatment plans.
Muscle tension and joint stiffness
Limited jaw movement often stems from muscle spasm, which can severely limit how wide you can open your mouth. The problem typically starts after long dental procedures where patients keep their mouths open too long, get inflammation from injections, or suffer joint injuries.
Neck dysfunction and neural sensitivity
The jaw and neck share a two-way relationship where pain can travel between them. This happens because sensory nerve fibres from the trigeminal nerve and upper cervical nerves join in the trigeminocervical nucleus, which creates a path for pain to move between these areas.
Stress and posture
Stress directly affects jaw function through unconscious clenching and muscle tightness. Bad posture, especially when your head moves forward, can also lead to swelling, pain, and gradual breakdown.
How the HNJ Clinic Assesses Jaw Pain
The jaw is one of the most complex joints in the body, and problems can involve a complex interplay between the TMJ, upper cervical spine, cranial nerves, and facial muscles. That’s why we start out assessments with a one-hour consultation to really understand your jaw condition. We take this time to get into your history, symptoms and treatment goals properly.
We ask specific questions about your jaw pain’s origin, what makes it worse, any past dental work or injuries, and if you clench or grind your teeth. Your quality of life matters to us, and we want to know how these symptoms affect your diet and social activities.
Our full physical assessment looks at:
- Your jaw’s movement patterns and limitations
- Muscle tension from your jaw down to your shoulders
- Neural sensitivity in the surrounding areas
- Postural and neck involvement
We track your progress using four vital signs: how often pain occurs, how long it lasts, how intense it feels, and where it hurts. After 3-4 visits, we do another full check of these signs and see how much better you can move your jaw.
Find Relief With Our Expert Jaw TMJ Physiotherapists
Tried treatment for jaw pain before that didn’t work? You’re not alone. Many people start with jaw exercises and posture corrections that don’t address the underlying dysfunction.
You might not have considered physiotherapy your first step towards relief, but our specialists use targeted, hands-on treatments to find the root cause in the muscles, joints, and nerves around your jaw and neck.
Book a consultation online today to see how we can help you find real, lasting relief. Check out where our convenient locations are here.
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Nigel Smith, co-founder of The Headache, Neck & Jaw Clinic, has over 20 years of experience as a specialist physiotherapist in jaw, neck, and headache pain management. Initially pursuing sports physiotherapy, Nigel found his true calling in TMJ treatment following a chance encounter with an oral surgeon.
His personal experience with TMJ issues and his dedication to developing conservative treatment pathways have made him a go-to expert for Dentists and oral surgeons seeking alternatives to surgical options.
Nigel’s commitment to excellence includes advanced training with the Watson Headache® Institute and lecturing at the University of Queensland. His expertise, backed by decades of hands-on practice and training, makes him a respected leader in this niche field. You can read more about my background, here.