Jaw Dislocation

Aka: Jaw Dislocation, Mandible Dislocation, Temporomandibular Joint Dislocation, TMJ Dislocation, Reduction of Anterior Jaw Dislocation, Temporomandibular Joint Reduction

1. Pathophysiology
   1. Mandibular condylar process displaces from the mandibular fossa of the Temporal Bone
   2. Spasm of lateral pterygoid Muscle, masseter Muscle and temporalis Muscle prevents the jaw from relocating
2. 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 occur 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
3. Preparation: Anterior Relocation
   1. Consider Procedural Sedation and Analgesia
   2. Consider adjunctive local Anesthetic injection toward the lateral pterygoid Muscle and into the joint space
   3. Patient sits upright with head well supported
4. Precautions: Anterior Relocation
   1. Consider imaging (e.g. Panorex XRay or CT maxillofacial) prior to reduction attempt
   2. Consult maxillofacial surgery or otolaryngology if there is extensive associated facial Trauma
   3. While attempting reduction, examiner should avoid placing thumbs on molars (risk of bite)
   4. Articular cartilaginous disc anterior dislocation may prevent relocation (may require surgery)
5. Management: Relocation techniques for Anterior Jaw 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 should 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 massages over the dislocated condyle and Muscles to relax the Muscle spasm
      2. Examiner wraps fingers behind the angle of the jaw
      3. Ipsilateral side
         1. Examiner applies posterior/downward force with thumb against the anteriorly displaced manibular condyle
      4. Contralateral side
         1. Examiner applies posterior force with thumb against the normal mandibular condyle to stabilize it
         2. Examiner pulls the contralateral jaw angle forward with curled fingers
            1. Rotates the opposite displaced Mandible into position
6. Management: Post-reduction
   1. Avoid extreme mouth opening (e.g. yawning)
   2. Soft diet for first 2 weeks after reduction
   3. NSAIDs for pain
   4. Anticipate healing over following 1-2 weeks
   5. Consider soft Cervical Collar to prevent extreme mouth opening
   6. Follow-up with ENT or orofacial surgery
7. Complications
   1. Failed reduction (e.g. interfering articular cartilaginous disc)
      1. Surgical intervention may be needed in some cases
   2. Human Bite to examiner
   3. Injury to loose Dentition or dental hardware
8. References
   1. Gibbons (2018) Crit Dec Emerg Med 32(8): 13
   2. Ramos and Schmidt (2020) Crit Dec Emerg Med 34(3): 16-7
   3. Wu in Majoewsky (2012) EM:Rap 12(11): 11
   4. Chaudhry in Kulkami (2012) Medscape EMedicine: Mandible Dislocation
      1. http://emedicine.medscape.com/article/823775-overview#showall