Mandibular dislocation

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Background

Anterior Dislocation

  • Most common
  • Mandibular condyle is forced in front of the articular eminence
  • Risk factors: Prior dislocation, weak capsule, torn ligaments
  • Often occurs spontaneously while patient is yawning, "popping" ears, or laughing

Posterior Dislocation

  • Follows a blow to the mandible that may or may not break the condylar neck
  • Condylar head may prolapse into the external auditory canal

Lateral Dislocation

  • Often associated with mandibular fracture

Superior Dislocation

  • Occur from blow to the partially opened mouth
  • Associated with cerebral contusions, facial nerve palsy, deafness

Clinical Features

Anterior Dislocation

  • Difficulty speaking or swallowing
  • Malocclusion
  • Pain localized anterior to the tragus
  • Prominent-appearing lower jaw
  • Preauricular depression

Posterior Dislocation

  • Must examine the external auditory canal

Lateral Dislocation

  • Condylar head is palpable in the temporal space

Differential Diagnosis

Jaw Spasms

Evaluation

Always examine the cranial nerves to rule out concomitant injury.

Spontaneous

  • Likely an atraumatic anterior dislocation
    • Clinical diagnosis (no imaging required)

Traumatic Dislocation

  • Obtain a CT scan to evaluate

Management

Wrist Pivot Method[1]

Wrist-pivot-method.jpg
  • Place patient in seated position
  • While facing the patient, grasp the mandible with your thumbs at the apex of the mentum and fingers on the occlusal surface of the inferior molars.
  • Apply cephalad force with the thumbs and caudad pressure with the fingers
  • Then pivot your wrists.

Note: This is a more physiologic reduction technique for the provider, allowing greater and more sustained force to be exerted.

Older "Traditional" Technique

Posterior position
  • Place patient in seated position (anterior approach) or supine (posterior approach)
    • Advisable to wrap thumbs in gauze to guard against accidental bite
  • Placed gloved thumbs in patient's mouth over the occlusal surfaces of the molars, or lateral to patient's molars in buccal fold (to avoid being bitten)
  • Apply pressure downward (toward the feet) and then backward (posteriorly)

Tips

  • Massage the TMJ externally prior to beginning the reduction attempt.
  • Don't Forget the Analgesia!
    • Consider IV benzodiazepines, opioids, or procedural sedation.
    • Inject local anesthetic into the preauricular depression just anterior to the tragus.
  • If dislocation is bilateral it may be easier to relocate one side at a time.

Disposition

Admit

  • Open dislocation
  • Superior dislocation
  • Associated with fracture
  • Nerve injury
  • Inability to reduce

Discharge

Spontaneous, successfully reduced anterior dislocation with:

  • Soft diet
  • Tell patient not to open mouth wider than 2cm x 2wks
  • Tell patient to support the mandible with a hand when they yawn

References

  1. Lowery LE, Beeson MS, Lum KK. The wrist pivot method, a novel technique for temporomandibular joint reduction. J Emerg Med. 2004 Aug;27(2):167-70. http://www.ncbi.nlm.nih.gov/pubmed/15261360