What is lockjaw?
Lockjaw is a painful condition that makes it difficult to speak, eat and maintain oral hygiene. Lockjaw is most often temporary but if it becomes permanent, it can be life-threatening. Severe lockjaw can even affect swallowing and alter the appearance of the face.
Lockjaw, also known as trismus, is a condition in which a person is unable to open their jaws fully. Spasm in jaw muscles make the jaws rigid and prevent movement of the temporomandibular joint (TMJ), the hinge-like joint in the jaw that enables jaw movement.
Lockjaw is a painful condition that makes it difficult to speak, eat and maintain oral hygiene. Lockjaw is most often temporary but if it becomes permanent, it can be life-threatening. Severe lockjaw can even affect swallowing and alter the appearance of the face.
What causes lockjaw?
Lockjaw can be caused by many conditions which include the following:
Tetanus
Tetanus is a major cause of lockjaw. Tetanus is an infection from anaerobic bacteria known as Clostridium tetani. Anaerobic bacteria grow in an environment that lacks oxygen. C. tetani are commonly found in the soil, house dust, animal intestines, and human feces.
Tetanus does not spread from person to person. The C. tetani bacterial spores enter the body through puncture wounds or open sores; stepping on a nail is often a cause for exposure to tetanus. The C. tetani spores germinate in tissue that has low oxygen because of a wound or infection.
When the spores germinate or sprout, they release a toxin known as tetanospasmin which affects nerve cells that control muscles (motor neurons). As a result, the motor neurons get hyperactive, keep the muscles in a continuous state of contraction, and do not allow them to relax.
Tetanus may initially affect the area near the infected wound, but it can spread to other parts of the body. Tetanus symptoms most often start with lockjaw, and neck and facial muscle stiffness. Reflex spasms lasting from seconds to several minutes can occur with external stimuli such as light, sound, or touch.
Other causes of lockjaw include:
- Infections in the mouth, inner ear, throat, or jaw, such as:
- Mumps
- Tonsillitis
- Abscesses
- Traumatic injury to the jaw or jaw muscles
- Inflammation of soft tissue in the mouth and jaw caused by medical conditions such as:
- Pericoronitis (inflammation in the tissue around a tooth)
- Arthritis in the jawbone
- Scleroderma, an autoimmune disease
- Dental surgery that requires keeping the jaw wide open for a long time
- Head and neck cancers and their treatments
- Certain medications that affect motor neuron function
What are the symptoms of lockjaw?
In addition to spasming of the jaw muscles, other symptoms of lockjaw may include:
- Jaw pain
- Difficulty in biting and chewing
- Difficulty swallowing
- Headache
- Earache
- Dryness and soreness in the mouth
In the case of lockjaw from tetanus, the progression of the disease can result in complications such as:
- Breathing difficulty
- Dislocations and fractures
- High temperature
- High blood pressure and heart rate
- Rhabdomyolysis, a life-threatening condition in which muscle cells break down
How do you treat lockjaw?
The primary lockjaw treatment focuses on the appropriate treatment for the underlying medical condition and can vary widely. Treatment for lockjaw is usually to provide symptom relief.
Following is the treatment for tetanus, a major cause of lockjaw:
Tetanus
Vaccination is extremely effective in preventing tetanus. Children in the US are administered a series of five doses of tetanus vaccine (DtaP, in combination with diphtheria and pertussis vaccines) from age two months to six years. Adults are recommended to take a booster dose every 10 years (Td or Tdap).
Tetanus treatment after exposure involves:
- Cleansing the wound thoroughly
- Taking antibiotics such as metronidazole, to kill the bacteria in the infected site
- Taking tetanus immune globulin (TIG) to neutralize the tetanus toxin
Tetanus immune globulin can, however, neutralize only the toxin that is not bound to neurons. Damage to motor neurons from the toxin is irreversible and muscle recovery can occur only with the sprouting of new nerve endings. People who contract tetanus may require several weeks of intensive care.
Tetanus exposure does not result in immunity to tetanus, and the patient will still require tetanus vaccination, in addition to treatment. Ultimately, the best protection from tetanus is not to miss the scheduled vaccinations for yourself and for your children.
Symptom relief
The treatments for symptom relief from lockjaw are mostly simple remedies that include the following:
- Medications such as:
- Use of jaw stretching devices
- Physical therapy with jaw stretching exercises
- Use of warm compresses to loosen the jaw muscles
- Cold packs to reduce jaw pain
- Eating soft foods that are easier to eat with a locked jaw
- Including calcium and magnesium-rich foods in your diet
- Staying well-hydrated