II. Pathophysiology

  1. Mandibular condylar process displaces from the mandibular fossa of the Temporal Bone

III. Types

  1. Anterior dislocation (most common)
    1. Most often occurs with extreme mouth opening
    2. May occur after laughing, yawning, Vomiting, taking a large bite or Trauma
    3. Also reported to occurr with oral sex, dental extraction, Tonsillectomy or general anesthesia
    4. Patient presents with an open locked jaw
  2. Posterior dislocation
    1. Typically due to direct blow to chin
    2. Associated with injury to external auditory canal
  3. Superior dislocation
    1. Typically due to direct blow to a partially open mouth
    2. Associated with glenoid fossa Fracture, Skull Fracture, CSF leak, as well as CN 7 and CN 8 injury
  4. Lateral dislocation
    1. Associated with MandibleFracture

IV. Preparation: Anterior Relocation

  1. Consider Procedural Sedation and Analgesia
  2. Patient sits upright with head well supported

V. Precautions: Anterior Relocation

  1. Consider imaging (e.g. Panorex XRay or CT maxillofacial) prior to reduction attempt
  2. While attempting reduction, examiner should avoid placing thumbs on molars (risk of bite)
  3. Articular cartilaginous disc anterior dislocation may prevent relocation (may require surgery)

VI. Management: Relocation techniques for anterior dislocation

  1. Self-reduction method
    1. May reduce spontaneously in some cases with patient opening jaw wider
  2. Intra-oral Jaw method
    1. Examiner wraps both their thumbs for protection against biting
      1. Sandwhich each thumb between two halves of a Tongue depressor
      2. Wrap each with kerlix or similar gauze roll
    2. Examiner places one thumb on each of the patient's lower molars
      1. Wrap fingers around the under-side of the Mandible
    3. Apply downward pressure
      1. Dislodge the mandibular condyle from beneath the zygomatic arch
    4. Push the Mandible posteriorly so it relocates into the glenoid fossa
  3. Wrist-pivot method
    1. Examiner places fingers on each side of the patients mouth
      1. Fingers are draped over the teeth from the lateral incisors posteriorly
      2. Thumbs wrap underneath and apply pressure to the underside of the chin
    2. Wrist pivots and applies downward traction on the jaw
    3. Push the jaw posteriorly and superiorly and it shoul re-seat in back in the glenoid fossa
  4. Extraoral method
    1. Examiner applies thumbs to bony prominence over the cheek bone, below the zygomatic arch
      1. This prominence represents the anteriorly displaced mandibular condyle
    2. Examiner wraps fingers behind the angle of the jaw
    3. Examiner pushes the jaw downward with thumbs and pulls forward with fingers to clear the edge of the glenoid fossa

VII. Management: Post-reduction

  1. Avoid extreme mouth opening
  2. Soft diet for first 2 weeks after reduction
  3. Soft Cervical Collar to prevent extreme mouth opening
  4. Follow-up with ENT or orofacial surgery

VIII. References

  1. Wu in Majoewsky (2012) EM:Rap 12(11): 11
  2. Chaudhry in Kulkami (2012) Medscape EMedicine: Mandible Dislocation
    1. http://emedicine.medscape.com/article/823775-overview#showall

Images: Related links to external sites (from Bing)

Related Studies (from Trip Database) Open in New Window