Sore jaw, locked jaw, woman in pain

Imagine not being able to open or close your mouth. For those with lock jaw, this can be a scary experience. While it may sound like a rare occurrence, an estimated 5-12% of people have had their jaw lock at some point in their lives.  But what exactly is lock jaw? What causes it, and how can it be treated? First, let’s take a closer look at this emergency condition and how it may affect you.

Patient having lock jaw pain

What is Lock Jaw?

Lock jaw, or jaw lock, is a condition caused by the temporomandibular joint (TMJ). The condition causes the lower jaw to become stuck – or locked – in two locks:

  • Open Lock: This occurs when the mouth cannot fully close, or you cannot bring their teeth together.  
  • Closed Lock: This occurs when the mouth is stuck in a closed position. You may not be able to open your mouth wide enough to fit two fingers.

Anything that can cause the TMJ to become misaligned can cause jaw lock. Eventually, the articular disc that keeps the upper and lower jaws in place can actually become dislocated. When this happens, the jaw may get “locked” in an open or closed position.

Jaw lock can occur for a variety of reasons, including but not limited to:

  • Injury to cartilage in the jaw, sometimes caused by clenching or grinding
  • A bad bite causing facial and jaw muscles to become inflamed
  • Muscle strain or spasms
  • Temporary dislocation of the TMJ
TMJ Joint Disorder

Prior to lock jaw, patients may experience:

  • Pain when moving the jaw
  • Stiffness
  • Popping noises
  • Earaches or ear ringing
  • Jaw clicking
  • Facial pain
  • Nerve pain at home

Sometimes, jaw lock can occur without warning, which can be very distressing for patients. To make matters worse, the process of trying to reposition the jaw can be very painful.

In most cases, patients have no idea why or how their jaw became locked. Often, it’s a build-up of several factors over time.

Other Causes of Lock Jaw

TMJ disorder and muscle strain are the two most common causes of lock jaw, but the condition can also be caused by:

Wisdom Teeth

Sometimes, when wisdom teeth erupt in a poor position, they can cause lock jaw. Here’s how:

  • If the wisdom teeth are infected, they can cause swelling that limits the jaw’s movement.
  • The teeth my push on the jaw and keep it from moving properly.

Removing the wisdom teeth can help resolve the issue with lock jaw and prevent other complications.


Inflammation can also cause lock jaw, particularly if caused by trauma from an accident. Swelling in the jaw area can limit its movement, which may lead to lock jaw.

Teeth Grinding

Teeth clenching and grinding, also known as bruxism, is a common problem that can be caused by dental problems, stress, genetics or misaligned teeth. One big issue with teeth grinding is that it often occurs at night, and patients don’t even realize it’s happening.  

Anterior teeth attrition

If it’s consistent, bruxism can cause tightness and soreness in the neck, jaw and face. In some cases, it can also cause earaches and headaches.  

Eventually, teeth grinding can lead to lockjaw and is often a sign of TMJ disorder.

Before and After Attrition Wear

Tetanus (Rare)

Although it is rare today, lockjaw can also be caused by tetanus. Tetanus is a serious bacterial infection, and one of its first symptoms is lockjaw. Why? Because the infection affects the nervous system and muscles in the body, causing them to tighten up and contract.

Most Canadians have been vaccinated to prevent tetanus, so the infection is rare.  

What to Do if Your Jaw Locks

If your find yourself with a locked jaw, the first and most important thing is not to panic. Fear and anxiety can cause additional tension in the neck, which will only make it harder to unlock the jaw.

Once you’ve relaxed, try following these steps:

  • With your jaw as relaxed as possible, place your palms on each side of your jaw.
  • Try very gently to wiggle your jaw back and forth and side to side.

Sometimes, a gentle wiggle is enough to pop the disc back into place. If you experience any pain, stop immediately. It’s important to be gentle when trying to move your jaw back into place to prevent injury.

If this doesn’t work, you can try:

  • Using a warm compress to loosen the tight jaw muscles. You may need to apply a compress several times a day.  
  • Using a cold compress if you’re experiencing pain. The cold will help reduce pain and inflammation.  
  • Take an over-the-counter anti-inflammatory every six hours.
  • Practice stretching the jaw 2-3 days per day to loosen up the jaw muscles.
  • Stay hydrated. Drinking water will help keep your jaw muscles loose and encourage a healthy body.
  • Limit stress and anxiety. Psychological stress can lead to jaw clenching, which may only make the lock jaw worse.
  • Consume calcium- and magnesium-rich foods. This may not be an immediate fix, but foods rich in these nutrients may help with TMJ issues.

If you are unable to gently move your jaw back into place on your own, the next step is to schedule an appointment.  

We can help with your lock jaw and also help treat issues with your TMJ that caused the lock jaw in the first place.  

Even if you are able to wiggle your jaw back into place, consider making an appointment with us if lock jaw is frequently occurring.

Exercises to Alleviate Jaw Tightness

There are several exercises you can perform to loosen tight jaw muscles, which can help alleviate lock jaw. These exercises include:

  • Smile stretch: Make the widest smile you can make without feeling pain or tightness. Now, slowly open your jaw two inches. Take a deep breath. Repeat 5-10 times.
  • Stretch the jaw: Push the tip of your tongue onto the roof of your mouth. Apply gentle pressure and slowly open your mouth as wide as you can. Now, slowly close your mouth. Make sure that you stop when you feel discomfort. Avoid this exercise if you’re already in pain.

These two simple exercises can help keep your jaw muscles loose and may help relieve lock jaw.

Professional Treatment of Lock Jaw

If lock jaw does not resolve itself, professional treatment is the next step. Treatment may involve the following:

  • Mobilizing the joint
  • Surgery to remove sticky adhesions
  • Flushing the joint
  • Injections  
  • Bite guards

Treatment will depend on several factors, including:

  • How long you have had lock jaw
  • The severity of the condition
  • Which treatment options have been tried

We will typically recommend conservative treatments first, such as a warm compress, gentle massage or ice pack. These can help relax the jaw and allow it to move back into place.

If these conservative treatments aren’t successful, the next step may be to try an injection or bite guard.

A custom-fitted bite guard can help stabilize the jaw to prevent uneven pressure. If that is inappropriate, an injection may do the trick.

Rarely, surgery may be required to resolve the issue.  

TMD Joint Pain

Arthroplasty to Treat Lock Jaw

Sometimes, lock jaw requires surgery to resolve the issue. Arthroplasty is the procedure used to restore function to a joint. In severe cases, surgery can help restore your ability to eat and chew normally while relieving pain and improving the quality of your life.  

Here’s how the procedure works:

  • First, an incision is made to expose the jaw joint.  
  • Next, the surgeon will reposition, repair or replace the disc using either an artificial disc or your own tissue.
  • The surgeon may also remove any bony growth or scar tissue that may have formed.

It’s important to note that arthroplasty is a major procedure and requires general anesthesia. Surgery is a last resort. In many cases, other treatment options can help resolve the issue.

The key is to prevent further damage.  

What Happens if You Don’t Treat Lock Jaw?

Unlike other dental issues, lock jaw is typically something patients don’t wait to treat. Lock jaw is uncomfortable, painful and often distressful.

But if treatment is delayed, lock jaw can have other consequences, such as:

  • Difficulty chewing and eating
  • Trouble breathing properly
  • Inability to fully open or close your mouth
  • Pain and severe discomfort
  • Sleep apnea symptoms

Over time, the ligaments in the jaw can have so many torn fibers that they become loose. At this point, the disc no longer moves back into place when you open your mouth. The problem is that because patients no longer feel pain or hear a clicking sound, they assume that the issue has been resolved on its own.

However, what they don’t realize is that the ball and socket of the joint no longer have the disc to cushion its movement. Bone-to-bone contact eventually deteriorates the joint, like it would with any other joint. The difference here is that your jaw needs to move hundreds of times a day to allow you to speak, eat, etc. At some point, even small movements in the jaw can cause pain. For example, some people experience pain simply by trying to eat a banana.

Is Lock Jaw a Dental Emergency?

Lock jaws can be dental emergencies. It really depends on the severity of the lock jaw and its cause.  

If your lock jaw doesn’t resolve itself within a few hours, give us a call to discuss your options.

The best way to prevent lock jaw is to schedule an evaluation if you experience any jaw stiffness or TMJ issues. Early intervention is the key to preventing severe TMJ and issues with lock jaw.

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Dr. Gurpreet Sidhu - Dentist at Lighthouse Dental Centre and Blue Water Dental
Dr. Gurpreet Sidhu

With nearly two decades of experience, Dr. Sidhu enjoys helping his patients learn about dentistry. Knowledge is meant to be improved, challenged and shared.

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