Fix that jaw drop: mandible dislocation management

Posted on by Kyle Remy

Let’s talk about mandible dislocations & how we can reduce them. First, we need to take a look at the mandible anatomy – can refer back to this as we discuss mandible dislocation:

So how does the mandible dislocate (also called temporomandibular joint dislocation)?

Causes:

Lateral dislocation
Anterior dislocation
  • Often due to trauma – direct blow
    • Can break condylar neck w/ dislocation
    • Lateral dislocations often w/ fracture
    • Check for loose or missing teeth!
  • Iatrogenic: ex. dental extraction, tonsillectomy, general anesthesia (the case I saw had happened during endoscopy)
  • Seizure
  • Spontaneous ex. with laughing, yawning, vomiting, even taking large bite of food!
  • Prior mandible dislocation = increased risk for recurrence
  • Dislocation Location:
    • Usually bilateral but can be one side
    • Anterior = most common: mandible condyle forced out
    • Posterior, superior, & lateral: severe trauma
    • Posterior = rare
    • Superior = bad: blow to partially open mouth > condylar head upward > badness – can have associated cerebral contusions, facial nerve palsy, deafness
  • How does the mandible get stuck there?
    • Muscle spasm traps mandible out of position- strong & mighty temporalis & lateral pterygoid muscles make reduction difficult
  • Symptoms: severe pain, difficulty speaking or swallowing
    • Anterior pain often right in front of tragus
    • Can have sensation loss part of chin or mouth
  • Signs:
    • Prominent lower jaw (in anterior), difficulty moving jaw
    • Palpable depression preauricular from displaced mandible condyle
    • If unilateral: jaw deviates away from dislocation
    • In posterior: condylar head can prolapse into auditory canal: examine external auditory canal & confirm hearing baseline
  • Diagnosis:
    • Clinical for the cooperative patient w/ spontaneous (atraumatic) anterior dislocation
    • Any trauma: CT max/face first – eval for fracture

Now that we know mandible is out, can we reduce it? There are several different techniques we can use:

Mandible reduction techniques

For closed anterior dislocation without fracture: reduce in ED ourselves
Superior or open dislocations or associated fracture: do not reduce it. consult ENT (or max-face surgeon depending on who is covering).

Setup:

  • Airway & hemodynamic monitoring
  • Can give short-active IV muscle relaxant like Versed: reduce muscle spasms
  • Full procedural sedation might be required to overcome muscle spasms
    • propofol = great choice – muscle relaxant effect
  • Alternative: local anesthesia: small-gage needle into preuauricular depression just anterior to tragus – inject 2 cc’s of 2% lidocaine

Anterior dislocation reduction: A few different techniques:

Syringe technique= the lazy way: patient gently bites down & rolls 5 or 10 cc syringe back & forth using top & bottom molars on affected side > gliding motion, mandible slides posteriorly

  • Can always try this one first but may need to move on to more forceful technique

Conventional method = most common technique:

  • Patient seated w/ head against wall or seat back
  • Cushion: tongue depressor on each side or layers of gauze
  • Your elbows at mandible level
  • Facing patient place gloved thumbs in mouth over lower molars as far back as possible
  • Curve fingers beneath angle & body of mandible
  • Apply thumb pressure downward & backward (toward the patient)
    • Slightly opening the jaw may help disengage it
    • Use STRONG pressure – jaw muscles are VERY strong! & you will have to overcome them
    • Sometimes easier to relocate one side at a time if bilateral

Alternate methods:

Wrist pivot method
  • Patient supine, stand at head of bed & thumbs on molars, downward & backward pressure (toward stretcher)
  • Wrist pivot method: patient & provider sit. Instead of thumbs on molars, fingers on molars & thumbs on chin, thumbs push up on chin while fingers push down on lower molars, wrist flexes, & mandible rotates into position
    • One randomized controlled trial found wrist pivot method w/ highest success rate
  • Extraoral method: patient seated, you in front of patient, thumb on cheek – ramus & coronoid process of dislocated side, then apply persistent posterior pressure. Fingers placed behind angle of mandible to stabilize grip. At same time on opposite side: fingers of other hand on angle of mandible & pulls towards you. Note that this causes further anterior dislocation on that side, rotates the jaw, & allows other side to be reduced.
    • Once one side reduced, other side often goes back spontaneously. If not, repeat on opposite side w/ minimal force to reduce 2nd side.
    • Another option: posterior force on both coronoid processes at the same time if above doesn’t work.
Extraoral reduction method

Unable to reduce? Get ENT involved.
Able to reduce – That jaw drop is fixed! Now what?

  • Know it’s successful when: patient able to easily close mouth

Post-reduction care:

  • No need for post-reduction imaging unless: reduction difficult or traumatic, or significant pain after
  • Complications = rare. Include fracture or articular cartilage avulsion
  • Disposition: after successful reduction can discharge home

Discharge instructions:

  • Soft diet
  • Don’t open mouth >2 cm x2 weeks
  • Support mandible w/ hand when yawning
  • NSAIDs for pain
  • Outpatient elective referral to oral max-face surgeon; severe cases may need intermaxillary fixation to control jaw motion during healing
  • Chronic dislocations may need operative intervention

Now you know how to diagnose & manage mandible dislocation! Jaw drop fixed!

Teaching Resident