11 Causes of Jaw Locking and Effective Treatments

Causes of jaw locking
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Jaw locking is a condition in which the ability to move the jaw is reduced. This happens when either the muscles controlling the jaw movements are not working properly or when there is a hindrance in the movement of temporomandibular joints.

Numerous causes of jaw locking exist but before discussing them, let us learn more about jaw locking and its symptoms.

There are four main muscles around the mandible (lower jaw). These muscles control jaw movement. The attachments and orientation of these muscles are such that it permits the mandible/ lower jaw to function in three planes. These muscles are:

  1. Masseter muscle: responsible for closing the mandible
  2. Temporalis muscle: also responsible for closing the mandible
  3. Medial pterygoid: responsible for closing and lateral movements of the mandible
  4. Lateral pterygoid: responsible for opening, deviation to either side and anterior movement of the jaw

The joint responsibility for the complex movement of the jaw is the temporomandibular joint (TMJ), commonly known as the jaw joint. It is a small, delicate joint right next to each ear. This joint is a connecting link between the jaw and the skull (temporal bone of the skull), allowing you to yawn, chew, and move your mouth to speak.

Causes of jaw locking
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Lockjaw affects the whole jaw, and the condition is usually experienced equally on both sides. A person with a lockjaw temporarily or, in many cases, permanently loses the ability to open and/or close the mouth. Lockjaw can happen suddenly and may reach peak intensity in just a few hours, usually accompanied by an immense amount of pain and discomfort.

Lockjaw is often diagnosed when the mouth opening is less than 20 mm. Other common symptoms of jaw lock are headaches, jaw pain, trouble chewing and earaches. If any compromised movement is present, there is a clicking sound with movement. There can also be some pain in the neck and shoulders when you open your mouth.

Causes of jaw locking
Source: by Wavebreakmedia/ UnlimPhotos

Causes of jaw locking:

There are many causes of jaw locking. The causes of jaw locking can vary vividly. From injury of the muscle, nerve, bone, tendon, or ligament to infections and medications, any reason can contribute as one of the causes of jaw locking.

Common possible causes of jaw locking are:

Temporomandibular Joint (TMJ) Disorders:

As discussed above, the temporomandibular joint is next to each ear (specifically- sides of your face, below your eyes, and toward your ears). It is this joint where the muscles, bones, tendons, and ligaments that control your jaw meet.

The temporomandibular joint disorder is one of the prime causes of jaw locking. The temporomandibular joint disorder is a condition affecting the jaw joints and surrounding muscles and ligaments, leading to compromised and painful movement of the jaw and ultimately can be one of the causes of jaw locking.

The temporomandibular joint disorder can be caused due to arthritis, facial trauma/ accident, or inflammatory disease.


Another one of the prime causes of jaw locking is Tetanus. Tetanus is also commonly known as lockjaw disease. It is a disease caused by a bacterial infection. The bacteria is Clostridium tetani.

Clostridium tetani, a bacterium commonly present in the environment (like in soil, on the surface of rusty tools, and ash), releases a life-threatening neurotoxin. Exposure to this toxin causes tetanus which can be fatal.

Tetanus leads to painful muscle contractions. When left untreated, it causes a person’s neck and jaw muscles to “lock,” making it hard to swallow or open the mouth (jaw locking) or even breathe, ultimately leading to death.

Vaccines can be given from time to time to prevent tetanus. There is no cure for this disease; however, antibiotics may be given by doctors.

Tetanus is highly suspected to be one of the causes of jaw locking because people suffering from tetanus always experience jaw locking. When jaw locking is a complication of tetanus, it can take weeks or even months for the condition to clear. However, now tetanus is extremely rare in most parts of the world because of vaccines available worldwide.


Cancer and cancer treatments can be one of the causes of jaw locking. Removal or radiotherapy can damage jaw structure or cause injuries to jaw parts responsible for its movement.

A person suffering from head or neck cancer or undergoing treatments for these types of cancers has a chance of developing lockjaw as a complication.

Rheumatoid arthritis (RA):

Rheumatoid arthritis is an autoimmune (body’s immune system attacks the healthy cells of the body) inflammatory disorder in which the joints and muscles are affected throughout the body.

Rheumatoid arthritis is one of the leading causes of jaw locking. Rheumatoid arthritis may damage the jaw joint and surrounding tissues joint of the jaw. It may also cause bone loss in the jaw.


Infection around the mouth can affect jaw movement. Having an infection around the mouth can be one of the causes of jaw locking. It is rare; however, it is possible that an infection can permanently damage muscles or nerves. This can lead to repeated short episodes of lockjaw.

Infections around the oral cavity, such as tonsilitis, can be one such example of infections that can be one of the causes of jaw locking.

Excessive chewing/ yawning:

Sometimes excessive chewing or yawning can lead to pain in the jaw joints. Chewing gum or any other substance in excess for an extended period of time may result in tightness in the lower jaw and jaw muscles.

While chewing or yawning, the bite may place unnecessary pressure on the facial, neck, and jaw muscles. One such example is when the top teeth don’t line up with the bottom teeth properly, which can lead to irritation, inflammation, and tightness of the nearby muscles. This makes the muscles stiff and, consequently, gives a locking sensation.


Stress and anxiety state can sometimes cause you to clench your jaw or lead to teeth grinding unintentionally. This not only happens unintentionally during the day, teeth grinding and teeth clenching can happen while sleeping as well. These actions cause pain and tightness in the jaw. The pain may worsen while eating or talking.

causes of jaw locking
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Teeth grinding (bruxism):

Teeth grinding (also known as bruxism), commonly known as clenching, can be caused by genetics, stress or dental problems (like misalignment of teeth).

Teeth grinding can happen during the day to while sleeping unintentionally. Teeth grinding can hence be one of the causes of jaw locking. It leads to tightness or a feeling of soreness in the face, neck, and upper or mandible (lower jaw). It can also be the reason for headaches or earaches.

Facial trauma:

Sometimes an injury to the face or facial muscles can compromise the movement of the jaw and can hence be one of the causes of jaw locking. Facia trauma may cause tightness or pain. Potential causes of jaw locking or pain that are caused by jaw damage are blunt force, such as a striking injury, and even cancer treatments like surgery or radiation.


It is rare, but it is possible that some medications can be one of the causes of jaw locking and pain. Medications used for psychiatric and mental disorders and anesthetics can cause lockjaw or pain in the jaw.

Osteoarthritis (OA):

Osteoarthritis is a type of arthritis in which the cartilage (protective and flexible tissue at the ends of the bone) wears down gradually and worsens over time. It is not common, but osteoarthritis can occur within the temporomandibular joints and can be one of the causes of jaw locking.

Osteoarthritis leads to wearing down of the cartilage and hence deterioration and loss of function of the jaw bone and tissues. As a result, the jaw movements become tight and painful. The pain can also radiate to other surrounding areas.


Jaw locking can cause many health problems like:

There are high chances of tooth decay and ulcers. This happens because effective brushing and flossing are difficult, leading to compromised oral health.

Lockjaw condition may lead to bruxism. Bruxism is a condition which leads to teeth grinding and/or clenching of teeth unconsciously. This leads the tooth enamel to wear away or even leads to cracking of the teeth.

Malnutrition can be a consequence of lockjaw since proper nutrition is unable to reach the body because of difficulty in eating.

Another complication of jaw locking can be muscle stiffening which is more difficult to treat than muscle spasms since the former doesn’t respond as quickly to medications.

Treatment of jaw locking:

As we have discussed earlier, there are many causes of jaw locking. Therefore, the treatment depends on the causes of jaw locking.

It is a good idea to see a doctor and get yourself medically reviewed. This should be done as soon as you start experiencing jaw pain or discomfort that doesn’t go away on its own.

Hot or cold packs:

The application of hot or cold packs can help in pain relief. It helps to loosen the tension in the muscles. This works for mild to moderate cases of lockjaw.


Analgesics (drugs that reduce pain) and non-steroidal anti-inflammatory drugs like ibuprofen and acetaminophen can help in pain and discomfort caused by the inflammation of the muscles of the jaws. After a medical history and condition examination, doctors may prescribe certain antidepressants or muscle relaxers as per the need.


Corticosteroid injections into the joint or botulinum toxin (botox) into the jaw muscles may help reduce symptoms associated with a tight and painful jaw.


In certain cases, surgery may be the best option for people with TMJ disorders (temporomandibular joint disorder). Different types of medical procedures are available, according to the requirements, which can fix a problematic joint in the jaw.

Shortwave diathermy laser treatment:

Shortwave diathermy laser treatment is a therapeutic treatment that uses a high-frequency electric current to generate heat in the body. It can help increase blood flow and thereby relieve pain.


Many people find acupuncture pretty effective in cases of jaw pain. It is done by a professional who inserts tiny needles into strategic pressure points of the body, which may alleviate pain.


Massaging the jaw area may help increase blood flow and reduce muscle pain and tightness. This area has the temporomandibular joints located. For massage, you can try to open your mouth and simultaneously gently rub the muscles next to your ears in a circular motion. Do this many times a day and also before sleeping.


Mouth guards can help muscle tightness caused by teeth grinding and clenching in your sleep. There are several types of mouthguards available. Choice of the right mouthguard can be made through the type of condition you face. The doctor or dentist will suggest an appropriate mouthguard after you get medically reviewed by them.

causes of jaw locking
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A mouth guard for teeth grinding:

If you are facing teeth grinding during sleep, a dentist may suggest a mouthguard to finish the contact between your upper and lower teeth. This will help reduce and prevent further wear and tear of the teeth. It can help with jaw pain and tightness.

A mouthguard for joint disorders:

This type of guard helps in TMJ disorders. The dentist may suggest a mouth guard called a splint in such a case. They are designed to gently hold the mandible or lower jaw in a forward position so that the mandible protrudes towards the front of the mouth. This helps alleviate one of the TMJ symptoms, TMJ pain, by reducing the strain on the jaw bone and surrounding muscles.


Exercises can help lessen the pain and tightness of jaw muscles. There are several targetted muscles exercises and stretches you can try; some of them are:

manual jaw-opening stretch:

Gently repeat small mouth-opening and mouth-closing movements daily as a warmup. The next step is to put your fingers on the top of your front four bottom teeth.

Slowly and gently pull down the lower jaw until slight discomfort is felt on the right side of your jaw. Hold the position for 30 seconds, and then slowly release the jaw back to its original position. Do this stretch 3-4 times a day and then gradually increase the number of reps from time to time.

jaw joint stretch:

This exercise helps to stretch the muscles of the neck and jaw. Start by pressing the tip of your tongue onto the roof of your mouth, behind the front teeth (without touching the teeth).

Slowly open your mouth as wide as you can, then slowly close it shut while pressing your tongue on the roof of your mouth. Stop at the point where pain or discomfort is felt. Do this 10 times. However, avoid this stretch if you feel extreme pain or discomfort while doing this.

Smile stretch:

This stretch helps to reduce any stress in the facial muscles, upper or lower jaw, and neck. To get started, smile the widest smile as much as possible without feeling tightness or pain. Open your mouth up to 2 inches while holding this position.

Inhale deeply through your mouth, then exhale while letting go of the smile and return to the normal position. Repeat up to 10 times and then increase the reps over time.


Stress and anxiety are on the list of causes of jaw locking; hence, reducing stress and anxiety can help prevent jaw pain and tightness. Deep breathing exercises, face yoga, dancing, swimming, walking, and meditation can help reduce everyday stress.

causs of jaw locking
Source: by Wavebreakmedia/ UnlimPhotos 

Another on the list of cause of jaw locking is excessive chewing. Therefore, avoid excessive chewing exercises (chewing gum) that may overuse your jaw. Avoid food like steaks, raw carrots, and nuts, as they require excessive chewing. Eat soft foods, especially which are non-sticky.

Get yourself vaccinated and get a booster shot from time to time for tetanus to prevent one of the causes of jaw locking.

The Prevalence of Temporomandibular Joint And Muscle Disorder
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Saima Qureshi
Currently pursuing a Bachelor's degree in Pharmacy, Saima has a keen interest in reading various ongoing research related to discoveries in the field of medicine. She has written many articles regarding health, lifestyle, and medicine for Icy Health on multiple topics such as Jaw Locking, Thyroid, and Herpes. She ensures that the articles she writes are always scientifically accurate and help in bringing a positive lifestyle change in anyone reading them. She plans on working in the Research and Development sector of the Pharma industry after her education.
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