What is Lockjaw? Unveiling Causes, Symptoms, Treatments, and the Spectrum in Between

  Jan 18, 2024
Reviewed by Geeta Singh

To answer ‘What is Lockjaw’ in simple terms, it is limited mouth opening due to muscle contraction. Also known as trismus, the condition impacts 5-12% of people at some point in their lives. Lockjaw causes discomfort and pain, interfering with your daily lifestyle.

Imagine being unable to eat, drink, or brush properly due to reduced mouth opening. It could be nerve-wracking for anyone to maintain good oral health in such a situation.

If you’re looking to answer questions on treatment, prevention, and unlocking the jaw at home, you are at the right place.

What is Lockjaw?

As per the definition, Lockjaw is the inability of a person to fully open their jaw or mouth for less than 35 mm. 

The restricted jaw and mouth movement usually happens due to painful spasms of the oral musculature. 

Trismus is often considered a symptom of tetanus infection; however, the spasms that ultimately lead to lockjaw can also occur due to periodontal infections, injuries, temporomandibular joint (TMJ) disorders, or medications.

Difficulty in opening mouth

What are the Causes of Lockjaw?

Anything that can cause muscular contractions and spasms in the jaw muscles can potentially lead to lockjaw. Let’s take a look at major and minor factors that can lead to the onset of Lockjaw.

Major Causes of Lockjaw

The common causes that cause Lockjaw can be enumerated as:

  • Tetanus: Tetanus strikes the central nervous system with bacterial wrath. The bacteria, Clostridium tetani, secrete toxins, triggering spasms in the muscles of the jaw, leading to lockjaw.
  • Temporomandibular Joint Disorders: TMJ disorders are caused by the delocalization of the TMJ disc. TMJ can lead to swelling of the tissue around the jaw or contracting masticatory muscles, which can ultimately result in a locked jaw. So, it is better to keep tabs on innovations in the field of TMJ disorders.
  • Inflammation: Conditions like pericoronitis, which is inflammation of the gums surrounding the teeth, can lead to jaw locking. Disorders like scleroderma, arthritis, and soft tissue fibrosis can also result in jaw locking due to inflamed jaw bones.
  • Oral Surgeries: Dental procedures like wisdom tooth extraction can sometimes initiate inflammation, which can lead to the locking of the jaw under adverse conditions.
  • Medicines: Lockjaw can be caused by the side effects of certain medications. For instance, the use of antipsychotic drugs and medicines used to prevent nausea has been recorded to cause lockjaw as a side effect.

Minor Causes of Lockjaw

Other than the above-mentioned causes, other factors that might cause Lockjaw can be:

  • Infections: Apart from tetanus, a few bacterial and viral infections like tonsillitis, mumps, and peritonsillar abscesses can cause inflammation, which might eventually lead to Lockjaw.
  • Oral Cancer Treatments:  Oral cancer treatment protocols sometimes cause injury to the soft tissues and muscles present in the jaw with radiation or surgeries, which can ultimately lead to lockjaw.
  • Hypocalcemia: A low level of calcium, known as hypocalcemia, often causes muscle spasms. These spasms, under specific conditions, can lead to lockjaw.
  • Diseases: A few disorders of nerves or muscles result in painful muscle contraction, which, under adverse conditions, can cause lockjaw.

What are the Symptoms of Lockjaw?

The locking effects usually occur in a symmetrical fashion on both sides of the face.

The jaw can get stuck or locked in the following two formats- 

  • Open Lock: A person can not bring their teeth together or fully close their mouth.
  • Closed Lock: A person cannot fully open their mouth or even to a level where two fingers can pass through.

Major Symptoms of Lockjaw

The major symptoms of trismus include: 

  1. Locking of the jaw is caused by muscle spasms.
  2. Jaw pain and cramps.
  3. Difficulty eating and biting the food due to limited movement of jaw and teeth.
  4. Unclear delivery of speech.

Minor Symptoms of Lockjaw

Although lockjaw can occur suddenly, it is sometimes preceded by subtle symptoms, including- 

  • Slight pain or discomfort in the movement of the jaw
  • Stiffness of the mouth
  • Ear ringing
  • Earaches
  • Facial pain
  • Jaw clicking

What is the Difference Between Lockjaw, Jaw Lock, and Other TMJ Disorders?

Sometimes people use lockjaw, jaw lock, and temporomandibular joint (TMJ) disorders as interchangeable terms. However, contradictory to people’s beliefs they are not the same thing at all. So, if you are wondering how to stop lockjaw, you should start by understanding the difference between lockjaw and other jaw disorders. 

While TMJ disorders include a wide range of ailments related to the temporomandibular joints, lockjaw is more likely to be caused by the stiffening of the joint. On the other hand, jaw lock can be a symptom or condition caused by joint disorders. 

One of the major differences between lockjaw and other disorders is that, while the effects of lockjaw can be felt equally on both sides, the impact of TMJ disorders is mostly one-sided.

Is Lockjaw a Serious Problem?

Lockjaw can be considered a serious problem for your jaws. The severity of this condition depends a lot on its cause and the severity of the cause. 

Identifying the root cause and its intensity is crucial in determining the urgency and learning how to fix Lockjaw immediately if need be.

When to See a Doctor if You Have Lockjaw?

Anyone experiencing stiffness of the jaw, difficulty in movement of the mouth and jaw, or having a history of injury to the oral cavity or diseases like tetanus, oral cancer, etc. can be at risk of lockjaw. 

If any of these conditions develop, it is advisable to seek prompt medical consultation before they get worse and understand how to fix Lockjaw.

Jaw pain

What Are the Prolonged Effects of Lockjaw?

Persistent episodes of lockjaw that last beyond a few days not only affect oral health but also pose a serious problem for your overall health. Prolonged lockjaw may lead to the following adverse conditions- 

  • Oral issues: Limited mouth and jaw movement can make it difficult for you to brush and clean your mouth properly, which can ultimately result in tooth decay and oral ulcers.
  • Bruxism: Lockjaw often causes grinding and clenching of teeth (bruxism). Continuous grinding can wear down the enamel, which can lead to sensitivity.
  • Delayed recovery: Prolonged episodes of lockjaw also lead to muscle stiffening for an extended timeframe, which makes the recovery a lot harder and time-consuming.
  • Malnutrition: Difficulty in opening and closing of mouth for a long time can cause an inability to eat food properly. This can further lead to anemia and other dietary deficiencies.

How is Lockjaw Diagnosed?

Diagnosis of lockjaw includes the conduction of tests and examinations to identify the root cause behind the jaw stiffening and muscular spasms. 

Identification is mostly done by encompassing a detailed evaluation of your medical history and symptoms. That being said, let’s take a look at the methods through which Lockjaw can be diagnosed. 

Physical Examination Required for Lockjaw Diagnosis

On average, a person can open their mouth up to 1.4 to 2.2 inches (35 to 55mm) wide. But if you have Lockjaw, it goes down to 1.2 inches. It is recommended that you consult a dental professional as soon as you start noticing the symptoms. 

The dentist will gauge the extent of mouth opening and look for symptoms like- 

  • Whether you have any pain while opening your mouth.
  • If you are having difficulty moving your jaws properly.
  • Whether your teeth are clenched.
  • If you have any stiffness in your jaw muscles.

Tests Required for Lockjaw Diagnosis

Additional tests may be required if the person has a history of oral and maxillofacial surgery, infection, or tumor. These tests are essential to identifying the exact cause of the lockjaw.

Tests like X-rays, MRIs, and CT scans are often used to detect the lesions in and around the oral cavity.

Oral examination of Lockjaw

Professional Treatment of Lockjaw

Lockjaw treatment often involves the use of muscle relaxants. Physical therapy also plays a major role in increasing the recovery rate. Let’s take a look at how to treat Lockjaw effectively.

  • Comprehensive treatment plan: Treatment of lockjaw majorly depends on its cause. For instance, if it has been caused by bacterial infections, then it may require antibiotic therapy.

    Healthcare professionals from the related departments, including Dentists, Oral surgeons, and Otolaryngologists (ENTs) may work together to identify the root cause of the problem.

  • Cortisone shots: In cases of lockjaw caused by inflammation, cortisone shorts are prescribed. These injections help relieve the inflammation in the target area.
  • Medication: Medicinal drugs are often recommended to ease intense muscle spasms and contractions.
  • Physical therapy: Physical therapy is prescribed alongside medicinal treatment to increase the pace of recovery. If you are wondering how to fix a locked jaw on one side, physical exercise might be helpful to relieve some pain.
  • Speech therapy: Speech therapy can help alleviate the pain in muscles and tissues around the jaw. It also helps you regain control over your oral muscle movements.

    When it comes to Lockjaw, you need to apply all the methods possible for you. If you can’t afford to go to hospital, here is a YouTube video by Orthodontist Mike Mew on how to fix a locked jaw at home:

What are the Home Remedies to Cure Lockjaw?

Seeking professional care is recommended, but you can try a few home remedies mentioned below to ease the excruciating pain and discomfort caused by Lockjaw. So, how to unlock a locked jaw at home? Let’s find out.

  • Warm Compress: Applying a warm compress to the jaw and neck area daily, at least twice for 20 minutes per session, can help increase the blood flow in the affected area and relieve the pain caused due to muscle stiffness. 
  • Cold compress: Cold compress can be used to numb the excruciating pain with ice packs or ice cubes wrapped inside a towel. It’s noteworthy that ice should never be applied to the skin directly.
  • Hydration: Drink enough water to ensure good muscular functioning. However, if it is too difficult to drink directly, use a straw instead.
  • Massage: Gently pressing and massaging the muscles around the jaw and the neck area, in a circular motion, can help in alleviating the pain and increase the blood flow. 

The recovery time for Lockjaw primarily depends on its underlying cause and the effectiveness of the treatment.  

Improvement can be seen in acute cases within days and weeks, while chronic patients may take much longer than usual to recover.

Prevention of Lockjaw

As the saying goes, prevention is always better than cure. Here are some tried and tested steps that you can implement to prevent lockjaw. 

  • Physical therapy: Incorporating professional physical therapy sessions that focus on TMJ is of great help. It can aid in preventing the recurrence of lockjaw caused by TMJ disorders.
  • Vaccination against tetanus: Getting tetanus shots is the most efficient way to prevent lockjaw caused by tetanus. 
  • At-home jaw exercises: Practicing active range of motion exercises and passive stretching can help prevent lockjaw caused by TMJ disorders. However, you would require a doctor’s set of instructions before trying these exercises. 

Bottom Line

To sum it all up, Lockjaw is caused by muscular contractions and spasms in the jaw and mouth. The blog has answered common questions like how to cure lockjaw; however, remember that the ways to cure lockjaw may vary depending on the situation, and it is better to seek a professional service.


Tetanus – Centers for Disease Control and Prevention
Tetanus – Wikipedia