4.02 Jaw Dislocation
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agk's Library of Common Simple Emergencies

Presentation
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The patient's jaw is "out" and will not close, 
usually following a yawn, or perhaps after 
laughing, a dental extraction, jaw trauma or a 
dystonic drug reaction. The patient has 
difficulty speaking ans may have severe pain 
anterior to the ear. A depression can be seen 
or felt in the preauricular area and the jaw 
may appear prominent.

What to do:
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- If there was no trauma (and especially if the 
   patient is a chronic dislocator) proceed 
   directly to attempt reduction. If there is 
   any possibility of an associated fracture, 
   obtain x-rays first.
- Have the patient sit on a low stool, his back 
   and head braced against something firm-- 
   either against the wall, facing you, or with 
   the back of his head braced against your 
   body, facing away from you.
- With gloved hands, wrap your thumbs in gauze, 
   seat them upon the lower molars, grasp both 
   sides of the mandible, lock your elbows, 
   and, bending from the waist, exert slow, 
   steady pressure down and posteriorly. The 
   mandible should be at or below the level of 
   your forearm.
- In a bilateral dislocation, attempt to reduce 
   one side at a time.
- If the jaw does not relocate easily or 
   convincingly, you may want to reassess the 
   dislocation with x-rays, and try again using 
   intravenous midazolam to overcome the muscle 
   spasm and 1-2ml of intraarticular 1% 
   lidocaine to overcome the pain. Inject 
   directly into the palpable depression left 
   by the displaced condyle.
- After reducing the dislocation it will be 
   comforting to apply a soft cervical collar 
   to reduce the range of motion at the 
   temperomandibular joint (TMJ). Recommend a 
   soft diet and instruct the patient to refrain 
   from opening his mouth too widely. Prescribe 
   analgesics if needed.
- If reduction cannot be obtained using the 
   above techniques, then consider admission 
   for reduction under general anesthesia.

What not to do:
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- Try not to get your thumbs bitten when the 
   jaw snaps back into position. Maintain firm, 
   steady traction and protect your thumbs with 
   gauze.
- Do not put pressure on oral prostheses that 
   could cause them to break.
- Do not attempt to reduce a TMJ dislocation 
   with the patient's jaw at the height of your 
   shoulders or above. You will need the 
   leverage you get from having the patient in 
   a lower position.
- Do not try to force the patient's jaw shut.

Discussion
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The mandible usually dislocates anteriorly, and 
subluxes when the jaw is opened wide. Other 
dislocations imply the presence of a fracture 
and require referral to a surgeon. Dislocation 
is often a chronic problem (avoided by limiting 
motion) and associated with temporomandibular 
joint dysfunction. If dislocation is not 
obvious, then consider other conditions, such 
as fracture, hemarthrosis, closed lock of the 
joint meniscus, and myofascial pain.

References 
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- Luyk NH, Larsen PE: The diagnosis and 
   treatment of the dislocated mandible. *Am J 
   Emerg Med* 1989;7:329-335.

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