What is trismus?

Trismus, also sometimes called lockjaw, is a painful condition in which the chewing muscles of the jaw become contracted and sometimes inflamed, preventing the mouth from fully opening.

For most people, fully opening the mouth means opening it beyond 35 millimeters (mm)Trusted Source wide — a little greater than the width of two fingers.

When the mouth’s opening movement is restricted, a number of problems can arise. These include feeding and swallowing problems, oral hygiene issues, and even difficulty speaking.

While trismus is not widespread in the population, it’s sometimes commonly seen in certain groups, particularly in those who:

• have had oral surgery to remove their wisdom teeth
• have had head and neck cancer in a region involving structures that influence mouth movement
• have undergone surgery or radiation treatment to the head and neck

Trismus is not the same condition as tetanus, which is also sometimes called lockjaw. Tetanus is an infection causedTrusted Source by the bacterium Clostridium tetani.

Because there’s a vaccine for preventing tetanus, it’s a rare infection in the United States. However, when tetanus does occur, you may have muscle stiffness and spasms that are painful and could occur anywhere in the body. A notable area where this occurs is in the head and neck region, where it causes trismus.

Treatment Options

Trismus is more commonly temporary than permanent. But the earlier you start treatment, the better the chance for a greater recovery. Some treatment options include:

• Use of a jaw-stretching device. These devices fit between the upper and lower jaw. A physical therapist will tell you which stretches to perform and how often.
• Medication. Your doctor may recommend or prescribe a muscle relaxant, pain reliever, or anti-inflammatory medication. Some research suggestsTrusted Source that combining corticosteroids and nonsteroidal anti-inflammatory drugs may be effective at decreasing post-operative trismus.
• Physical therapy. This typically involves massaging and stretching the jaw to help loosen the muscles and decrease pain.
• Dietary changes. Following a soft food diet and avoiding hard, crunchy foods is often recommended to ease pain until symptoms improve.
• Acupuncture. While more studies are still needed, some research suggestsTrusted Source that acupuncture could be beneficial for muscle relaxation and pain management in disorders affecting the jaw muscle.
• Craniosacral therapy. This gentle, hands-on form of alternative therapy has been shownTrusted Source to help reduce chronic pain. Craniosacral therapy is often performed by chiropractors, massage therapists, and osteopaths.