Fact Checked

Lockjaw is defined as difficulty opening the mouth due to the spasms affecting the muscles for chewing.

Generally, the mouth can be opened between 1.5 – 2.3 inches. If an individual has lockjaw, he/she can only open the mouth less than 1.4 inches.

An ideal way to check for limited mouth opening is to perform the three-finger test:

  • Position the index, middle and ring fingers together
  • Turn the 3 fingers so that they are vertical
  • Place the fingers between the front teeth

If the fingers fit amidst the front teeth easily, the individual should not be worried about lockjaw.

Is it common?

A delay in treatment can lead to contractures which are stiff and deformed joints that could not function properly.

With the availability of vaccinations, the cases of tetanus have reduced. Even though rare, lockjaw is a common symptom present if diagnosed with tetanus.

Nevertheless, if the individual has undergone treatment for cancer of the head and neck, there is a possibility of ending up with lockjaw.

The improvement in the techniques for both surgical and radiation therapies helped lower the cases of lockjaw. In addition, temporomandibular joint (TMJ) conditions can also lead to lockjaw.

Are there any associated symptoms?

Even though the usual symptom linked to lockjaw is difficulty opening the mouth fully, other symptoms are present such as:

  • Headache
  • Jaw pain
  • Dry mouth
  • Mucositis
  • Difficulty hearing
  • Ear pain
  • Difficulty swallowing
  • Speech difficulty
  • Dental issues linked to hygiene
  • Malnourishment linked to difficulty eating

Management for lockjaw

Prompt care is vital if an individual is experiencing lockjaw. A delay in treatment can lead to contractures which are stiff and deformed joints that could not function properly.

The commonly used treatment options include physical therapy, dental treatments and devices or tools to assist with range-of-motion. If the individual has issues with swallowing or talking, speech therapy is necessary.

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