How are TMJ, Lockjaw, and Jaw Lock Related?

Though TMJ, lockjaw, and jaw lock are often used interchangeably, they are not the same thing, and they describe very different things. TMJ refers to the temporomandibular joint or disorders associated with this joint. Lockjaw and jaw lock refer to conditions involving the TMJ. 

Briefly, jaw lock and lockjaw involve a tightening or stiffening of the TMJ, or temporomandibular joint. Jaw lock can be a symptom of a TMJ disorder (TMD), and TMD can cause jaw lock. Lockjaw is typically synonymous with the bacterial infection tetanus, because the infection can cause muscle spasms that lock the TMJ. Lockjaw is not caused by TMD, nor can it cause TMD.

Here’s a deeper dive into each of these terms.

What is TMJ?

The TMJ, or temporomandibular joint, consists of two joints–one on each side of the head, just under the ears–that connect the jawbone (mandible) to the skull (temporal bone). These are complex joints that work in unison with the muscles and ligaments surrounding the jaw, acting as sliding hinges to allow your jaw to move together side-to-side, back-to-front, and up and down so you can eat, chew, yawn, and talk properly. 

Like other joints in the body, the TMJ and associated muscles and tissues can become inflamed and sore as a result of stress, trauma, overuse, arthritis, or other strain, causing the TMJ to essentially malfunction. Abnormalities and disorders of the TMJ are referred to as TMJ, TMJ disorders, or simply TMDs. TMDs can vary widely in their severity, symptoms, and causes.

Problems with the TMJ can cause the jaw to sound like it’s clicking or popping when it moves as well as pain or stiffness in the muscles of the face and neck. Because of the joint’s proximity to the ear canal, TMD can also produce ear pain. TMD and TMJ disorders are frequently associated with conditions like bruxism (teeth grinding and clenching) and sleep apnea.

What is Jaw Lock?

Jaw lock can develop as the result of a TMJ disorder, such as a damaged TMJ disc cartilage, or temporomandibular joint displacement. Also known as internal disc derangement, TMJ displacement is an abnormal function of the mandibular condyle (a rounded structure at the back of the mandible), the mandibular fossa (a depression in the temporal bone that articulates with the mandibular condyle), and the jaw joint’s articular disc.

Jaw lock can also develop as a result of malocclusion (or a misaligned bite) or bruxism (clenching and grinding).

What Does Jaw Lock Feel Like?

Jaw lock feels like the jaw is catching, locking, or hooking, a sensation that occurs when the TMJ disc slips out of place and the jaw joint becomes misaligned. Jaw lock can be accompanied by headaches, migraines, and ear pain and may produce pain and soreness in the TMJ.

What Are the Symptoms of Jaw Lock?

Although jaw lock can sound and feel scary, it is not life-threatening. However, if it isn’t treated, it can become more frequent, painful, and severe over time as symptoms worsen. 

Jaw lock symptoms include:

• Cramping
• Soreness
• Discomfort, stress, tension, and/or pain in the jaw and facial muscles
• Difficulty opening and closing the mouth

Jaw lock is temporary and can occur intermittently, with the jaw momentarily stuck in a closed or open position, or the locking can be prolonged. It is also often unexpected; patients with jaw lock usually can’t predict when their jaw will stick.

How Are Jaw Lock and TMJ are Related?

Jaw lock is a symptom of a TMJ disorder, although TMJ disorders or TMD are not always accompanied by a locked jaw sensation. Jaw lock typically involves muscle and joint inflammation, usually due to a dislocated articular disc in the TMJ. This can result in stiffness and tightness in the TMJ, and can exacerbate any swelling or inflammation that may already be present.

Jaw lock can be treated as part of comprehensive TMJ or TMD treatment that might include physical therapy, medication like muscle relaxants or anti-inflammatories, or oral devices like night guards or dental splints. In some cases, oral surgery may be necessary to correct problems with your TMJ and address jaw lock.

What Is Lockjaw?

Lockjaw is used synonymously with tetanus because one of the most common symptoms of tetanus is a tightening, stiffening, or “locking” of the jaw. Tetanus produces a potent neurotoxin that affects the nervous system and can cause painful muscle contractions, spasms, and stiffness, including in the muscles of the face and jaw. This can cause the temporomandibular joint (TMJ) to tighten and feel “locked.” Tetanus itself can be deadly if not treated promptly, but vaccines have made the infection rare in the U.S.

What Causes Lockjaw?

Lockjaw can develop if an open cut or wound becomes infected with tetanus bacteria, which is common in the environment in soil, dust, and manure. Tetanus can enter the body through breaks in the skin such as from burns, puncture wounds, or compound fractures, as well as from surgical procedures, IV drug use, dental infections, and chronic sores or infection.

What Does Lockjaw Feel Like?

Lockjaw feels like a gradual stiffening of the muscles all over the body caused by painful muscle contractions, starting in the neck and jaw. It is typically felt equally on both sides of the jaw and can peak within a few hours of its sudden onset.  In addition to a locked jaw, individuals with a tetanus infection will also experience spasms in the chest, heart, face, stomach, back, extremities, and other voluntary muscles of the body. Breathing, swallowing, and speaking may become difficult, and fever, changes in blood pressure and heart rate, and irritability are all common.

What Are the Symptoms of Lockjaw?

Lockjaw may be one of the most widely recognized symptoms of tetanus, but the infection can produce a wide range of symptoms. 

The symptoms of lockjaw (tetanus) can include:

• Difficulty swallowing or speaking
• Jaw pain
• Earache
• Headache
• Dry mouth
• Sore or inflamed mouth
• Drooling
• Stiffness in the neck muscles
• Seizures
• High blood pressure
• Fast heart rate
• Fever and sweating

How Are Lockjaw and TMJ Are Related?

Lockjaw is a stiffening of the TMJ as a result of tetanus. Lockjaw is not caused by TMJ disorders or TMD, nor does tetanus (or lockjaw) cause the majority of jaw problems.

Lockjaw must be diagnosed by a medical doctor and cannot be treated with traditional TMD treatment modalities. Treating lockjaw usually requires hospitalization, antibiotics, aggressive wound care, and immediate treatment with human tetanus immune globulin medication. Serious infection may require breathing support.

What Should You Do if You Experience a Locked Jaw?

A locked jaw can be very scary, but it’s important not to panic; the adrenaline of fear can create more tension in the jaw, making it even more difficult to unlock. So do your best to relax as much as possible.

Try to identify if your locked jaw is the result of muscle tension, like with a TMD, or is the symptom of a tetanus infection.

• If it is associated with a TMD, you will likely feel an achy pain or soreness in your chewing muscles and maybe some mild discomfort in your neck, head, or shoulders. 
• If your locked jaw is developing from the onset of an infection, you will likely also be experiencing fever, muscle stiffness (as opposed to soreness), muscle spasms, difficulty breathing and swallowing, and changes in your heart rate and blood pressure. You or a loved one should contact a doctor or emergency room right away and seek immediate treatment.

If your jaw is locked because of TMD, you can help relieve it with:

• Manual jaw-opening exercises, where you use your hand to manually manipulate the jaw open and close until it loosens
• Jaw joint and smile stretches, to reduce pain and stress in the muscles of the face, jaw, and neck
• Massage, especially on your chewing muscles and along your jaw
• Relaxation and stress management techniques like deep breathing
• Warm compresses applied to the area
• Comprehensive splint therapy

You can also help prevent a locked jaw and reduce TMJ discomfort with over-the-counter medications like ibuprofen or acetaminophen, exercises to stretch and strengthen your jaw, and a night guard worn while you’re sleeping.

Treat Your TMJ and Jaw Lock with REstore TMJ & Sleep Therapy

While they are not life-threatening, TMJ disorders and jaw lock can be very painful and disruptive to your quality of life. Without treatment, they can worsen and begin to degrade your oral health and your overall health.

Dr. Katherine S. Phillips of REstore TMJ & Sleep Therapy has dedicated her career and her practice to treating TMJ and sleep disorders, helping hundreds of patients over more than a decade find relief from their TMD symptoms like jaw lock.

If you or a loved one have experienced frequent jaw lock, or suffer from jaw pain and discomfort more generally, call REstore TMJ & Sleep Therapy at 281-296-6797 to schedule a no-obligation consultation. Dr. Phillips will be able to identify the source of your pain and develop a comprehensive treatment plan to help you get back to living a normal life without jaw lock or jaw discomfort.

You can also take our self-guided TMJ quiz and fill out a convenient appointment request form. 

Don’t spend another day in pain, worrying about your jaw lock or other TMD symptoms. Contact us today!