What is Lock Jaw?

December 31, 2023

How to Treat TMJ-Related Lockjaw

By Dr. Cory Herman

This article will help dispel confusion between TMJ lockjaw and tetanus lockjaw and explain how TMJ-related jaw-locking is diagnosed and treated.

Jaw locking is a common symptom of a TMJ problem, although a locked jaw sensation does not always accompany TMJ disorders or TMD. As well it can be a symptom of tetanus. This can cause confusion for people suffering from jaw pain. Patients often describe it as feeling like limited or restricted mouth opening, “jaw locking” or “jaw tension.”

How does an Orofacial Pain Specialist treat lockjaw caused by TMJ?

Treatment for lockjaw typically begins with a comprehensive craniomandibular and dental exam to determine the cause of their jaw pain or limatations opeing the jaw. Obtaining an early diagnosis and treatment can be the difference between gaining a permanent solution or dealing with chronic TMJ pain

Once a dentist refers you to our pain clinic, we assess the patient’s issues based on factors like how long the issues have persisted, their severity, and any underlying health conditions that could be contributing to it.

We will begin by assess how non-surgical treatment may relieve jaw lockingTMJ-related issues.

Because the term lock jaw can be applied to other scinerios, let’s look at similarities, commonalities, and differences.

What is trismus?

Trismus is also commonly called “lockjaw” when associated with tetanus. It is a condition of limited jaw mobility. It may be caused by spasms of the muscles of mastication or a variety of other causes. Although uncommon, temporary trismus happens to people much more frequently than permanent trismus. It is known to interfere with everyday daily routines of eating, speaking, and maintaining proper oral hygiene.

According to the National Institutes of Health, “Trismus is commonly referred to as lockjaw and is usually due to sustained tetanic spasms of the muscles of mastication. Although it was initially described in the setting of tetanus, it is now used to refer to a bilateral restriction in mouth opening from any cause.

How are TMJ, Lockjaw, and Jaw Locking Related?

Jaw locking can be treated as part of comprehensive TMJ or TMD treatment, including oral appliances, also known as night guards or dental splints. But mouth guards are not used to treat the bacteria that causes tetanus. Dental surgery or lengthy procedures may be the cause of jaw locking and limited mouth opening. Medication like muscle relaxants or anti-inflammatories may be used short term to treat both.

Tetanus is a bacterial infection that can cause muscle spasms that lock the jaw. We’ll attempt to sort out how Tetanus “lockjaw” a TMJ “lockjaw” should be differentiated when it comes to unique causes, treatment, cure rates, and risks.

Periodontal and dental infections as well as medication side effects and also contribute to limited mouth opening. [1] Some conditions can result in stiffness and tightness in the TMJ and the muscles of chewing. This can exacerbate soft tissue swelling or inflammation that may already be present. Typically, with infection, spread of the bacterial cause is what exacerbates limited mouth opening.

Tetanus causes painful muscle contractions, particularly in the jaw and neck. It can interfere with the ability to breathe – however, this is different from sleep apnea. Having trouble breathing may be a symptom of either. This requires a professional diagnosis to really know where your lockjaw is coming from. The cause influences your jaw pain treatment. Meaning it is important to understand the cause of your lockjaw.

How are TMJ Lockjaw and Tetanus Jaw Lock Different?

Jaw locking and lockjaw refer to a tightening or stiffening of the temporomandibular joint. Often jaw locking can be the result of a displacement of the disc, or cushion, in your jaw joint. Tetanus lockjaw is commonly associated with a bacterial infection, whereas TMJ lockjaw is often due to a jaw injury, teeth clenching, or stresses on the jaw joint.

Comparing TMJ Lockjaw with Tetanus Jaw Lock
Definition “TMJ” refers only to the temporomandibular joint itself; “TMDs” refers to the disorders which affect the jaw joint and the associated supporting structures. They include a group of conditions that cause pain and dysfunction in the jaw joint and the surrounding muscles and ligaments. “Trismus” is a condition that involves muscle spasms in the temporomandibular joint (TMJ). It’s also known as lockjaw. Trismus occurs when the muscles used for chewing contract and don’t release. When someone can’t open their mouth more than 2 finger widths or approximately 1.3 inches, they’re considered to have trismus. [2] By some, it’s used to refer to a restriction in mouth opening from any cause.
Cause TMJ-related lockjaw is typically caused by jaw injuries, Bruxism, stresses on the jaw joint, etc. Tetanus can also cause lockjaw. Tetanus lockjaw is typically caused by a bacterial infection. This is due to sustained tetanic spasms of the muscles of mastication. Nervous system diseases including multiple sclerosis, scleroderma, and lupus may also be triggers.
Commonality TMJ is very common, affecting an estimated 10 million Americans. Tetanus is very rare in the United States, with about 30 cases reported each year. [3]
Treatment TMJ treatment is likely to include an oral appliance, also called a stabilization splint or bite guard, which is a custom made oral appliance guard that fits over the upper or lower teeth. A wide range of TMD treatments that take into account your symptoms, the possible causes, your lifestyle and more. Tetanus is typically treated with a toxoid-containing vaccine, tetanus immune globulin (TIG), or antitoxin. [4]
Symptoms Summary Typical symptoms are radiating pain in the face, jaw, or neck, jaw muscle stiffness, limited movement or locking of the jaw,painful clicking, popping or grating in the jaw joint when opening or closing the mouth, a change in the way the upper and lower teeth fit together. Tetanus jawlock typically involves muscle and joint inflammation; it is due to a bacterial infection (Clostridium tetani bacteria).
Cure TMJ pain. may managed be when proper treatment is received. With proper treatment, retraining habits of teeth grinding. or clenching, and/or removing what puts pressure on the joint, all symptoms may resolve. No current cure for tetanus is known. Treatment focuses on managing symptoms and complications while seeking to lessen the effects of the tetanus toxin. [3]
Death TMJ is not life-threatening. Tetanus rarely does but can cause death.

How long does TMJ-related locked jaw last?

Typically, expect an acute MJ-related locked jaw flare-up to last between a few hours to a few days. Rarely, they may remain for several weeks. If your TMJ symptoms don’t diminish substantially within this timeframe, talk to your Orofacial Pain Specialist about possible treatment options.With proper treatment, chronic TMD-related jaw locking can improve within weeks to months.

How does a pain clinic seek to treat a closed TMJ lock?

Common first-line treatments for closed TMJ lock jaw may include:


  • A mouth guard splint.li>
  • Trigger point injections.
  • Physical Therapy to relax tight jaw muscles and improve joint movement.
  • On rare occasions surgical intervention may be necessary.


Is TMJ lockjaw serious?

If you are worried about how serious TMJ lockjaw is, the first thing to do is try to relax. Tension in your head, neck, and jaw is only likely to escalate your pain levels. “Worry” and prolonged stress only exasperate lock jaw pain. While jaw lock may sound and contribute to feeling emotionally uneasy, it is not life-threatening. However, if it isn’t diagnosed and treated early enough, it can become more frequent, painful, and severe as your symptoms worsen.

You may be asking  Can TMJ be resolved?“; the good news is that treatment can definitely reduce pain symptoms.

When the jaw muscles suffer from sustained contraction called Trismus, the jaw might lock and pain increases. It then becomes helpful to have trigger issues assesed, like fibromyalgia and TMD relationship is occuring.

What are common symptoms of both tetanus and TMJ?

  • Locking of the joint, making it difficult to open your mouth.
  • Increased challenges chewing or pain while chewing.
  • Headache.
  • Jaw cramping.><l< span=””>i>A jaw that can lock open or lock shut.</l<>

What symptoms does tetanus have that TMJ does not?

Common symptoms of tetanus (missing with TMJ):

  • Sudden, involuntary stomach muscle spasms.
  • Muscle soreness, pain, and stiffness all over the body.
  • Muscle spasms can also affect your chest and back.
  • Jerking or staring-type seizures.
  • Fever and sweating.
  • Changes in blood pressure and heart rate. [4]

What symptoms does TMJ have that tetanus does not?

  • Difficulty to close your mouth as well as open (tetanus is only at opening).

If you have TMJ diagnosed, it does not necessarily result in a “locked jaw.” Locked jaw or lockjaw may be used as an umbrella term for many TMJ-related disorders.

What common treatments do TMJ and tetanus share?

Shared treatment of TMD and/or trismus often includes:

  • Giving your jaw a “chewing” rest with a soft food diet.
  • Medications for pain.
  • Jaw muscle relaxers.
  • At-home exercises to gently stretch the jaw.
  • Professional behavioral therapy.
  • Help to sleep better so that you heal faster.

IMPORTANT: If you have the above symptoms, this is not a medical diagnosis. Please see your treating physician and/or pain specialist as soon as possible. Here is a brief summary of what you can expect during your initial pain clinic visit.

What can a person do if experiencing locked jaw pain?

A locked jaw can be frightening. Just don’t panic or be overly stressed as the adrenaline of fear and spams may add more tension in the jaw. This can exacerbate your pain and make it even more challenging to unlock. So do your best to relax as much as possible.

While waiting for your jaw pain evaluation, try to:

  • Identify if your locked jaw is the result of muscle tension, or if it is the symptom of a tetanus infection.
  • Keep a written account of what you notice to share during your appointment.
  • Observe what level you have of discomfort in your neck, head, jaw, or shoulders.
  • Try smile stretches and record if it helps reduce pain and stress in your face, jaw, and neck muscles.
  • Gently massage your chewing muscles and along your jaw line.
  • Try deep breathing to aid relaxation and stress management.
  • Try applying a warm compress to your jaw area.
  • Reduce locked jaw pain and TMJ discomfort with over-the-counter medications like ibuprofen or acetaminophen.

If your locked jaw is developing from the onset of an infection, you will likely also be experiencing fever and jaw muscle stiffness (as opposed to soreness). Ask your pain specialist if this seems confusing with Burning Mouth Syndrome symsptoms.

We recieve frequent requests from dentists to see patients for:

– “Severe joint noises with pain.”

– “Joint noises/locking, late total occlusion of TMJ surgery, now periodic noise and mild pain.”

– “Patient has been treated by TMD specialist for locking jaw ~7-8 years ago. Patient is having recurrent symptoms even with the use of a hard acrylic splint. Patient was locked closed when she woke up two night ago. She reports worsening symptoms of pain and daily discomfort.”

– “Need appointment for a clicking, locking jaw that has been an issue for 6 months.”

– “Upper right law locking multiple times a day. Pain on palpation on both sides.”

– “Jaw locks on the left sometimes and it is making a lot of clicking sounds.”

“Whether or not your jaw problem is due to TMD or trismus, we urge you to see your doctor or a TMD specialist for diagnosis. This will include a medical history, including information about recent dental procedures or physical injuries, an exam to rule out structural or other abnormalities, and measurements of how wide you can open your mouth. Depending on what is found, additional imaging studies may be requested.” – Whether TMD or trismus, jaw trouble needs attention, March 26, 2021 by UCLA Health

The management of TMJ dislocation and jaw locking issues, whether “open lock” or “closed lock” is customized as per the underlying cause.

SUMMARY: How MN Head & Neck Pain Clinics Help TMJ Patients

If you’re experiencing pain or discomfort from lock jaw or TMJ dysfunction, consider visiting a trained specialist in TMJ disorders. Visit one of our team providers to learn more and find an appropriate TMJ treatment plan for you.

We offer multiple convenient locations where you can schedule a visit if you or someone you know is suffering from their jaw locking up or has TMJ concerns.

Plymouth: (763) 577-2484St. Paul: (651) 332-7474Burnsville: (952) 892-6222St. Cloud: 763-233-7252

About the Author

Cory Herman DDS, MS manages the MN Head & Neck Pain Clinic and works to coordinate both simple and complex chronic pain disorder treatments. At our MN pain clinics, Dr. Herman and other TMJ and Orofacial Pain specialist have treated patients with TMJ and jaw problems on regular basis.


[1] https://arthritis-research.biomedcentral.com/articles/10.1186/s13075-023-03129-0

[2] https://www.uclahealth.org/news/whether-tmd-or-trismus-jaw-trouble-needs-attention

[3] https://health.hawaii.gov/docd/disease_listing/tetanus/

[4] https://www.health.ny.gov/diseases/communicable/tetanus/

[5] https://www.mayoclinic.org/diseases-conditions/tetanus/symptoms-causes/syc-20351625

[6] https://www.cdc.gov/tetanus/about/symptoms-complications.html



Our mission is to provide high-quality, effective patient care for head and neck disorders through a multispecialty, interdisciplinary approach designed to reduce pain and improve function for all our patients.

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