II. Pathophysiology
- Mandibular condylar process displaces from the mandibular fossa of the Temporal Bone
- Spasm of lateral pterygoid Muscle, masseter Muscle and temporalis Muscle prevents the jaw from relocating
III. Types
- Anterior dislocation (most common)
- Most often occurs with extreme mouth opening
- May occur after laughing, Yawning, Vomiting, taking a large bite or Trauma
- Also reported to occur with oral sex, dental extraction, Tonsillectomy or general Anesthesia
- Patient presents with an open locked jaw
- Posterior dislocation
- Typically due to direct blow to chin
- Associated with injury to external auditory canal
- Superior dislocation
- Typically due to direct blow to a partially open mouth
- Associated with glenoid fossa Fracture, Skull Fracture, CSF Leak, as well as CN 7 and CN 8 injury
- Lateral dislocation
IV. Preparation: Anterior Relocation
- Consider Procedural Sedation and Analgesia
- Consider adjunctive Local Anesthetic injection toward the lateral pterygoid Muscle and into the joint space
- Patient sits upright with head well supported
V. Precautions: Anterior Relocation
- Consider imaging (e.g. Panorex XRay or CT maxillofacial) prior to reduction attempt
- Consult maxillofacial surgery or otolaryngology if there is extensive associated facial Trauma
- While attempting reduction, examiner should avoid placing thumbs on molars (risk of bite)
- Articular cartilaginous disc anterior dislocation may prevent relocation (may require surgery)
VI. Management: Relocation techniques for Anterior Jaw Dislocation
- Self-reduction method
- May reduce spontaneously in some cases with patient opening jaw wider
- Intra-oral Jaw method
- Examiner wraps both their thumbs for protection against biting
- Sandwhich each thumb between two halves of a Tongue depressor
- Wrap each with kerlix or similar gauze roll
- Examiner places one thumb on each of the patient's lower molars
- Wrap fingers around the under-side of the Mandible
- Apply downward pressure
- Dislodge the mandibular condyle from beneath the zygomatic arch
- Push the Mandible posteriorly so it relocates into the glenoid fossa
- Examiner wraps both their thumbs for protection against biting
-
Wrist-pivot method
- Examiner places fingers on each side of the patients mouth
- Fingers are draped over the teeth from the lateral incisors posteriorly
- Thumbs wrap underneath and apply pressure to the underside of the chin
- Wrist pivots and applies downward traction on the jaw
- Push the jaw posteriorly and superiorly and it should re-seat in back in the glenoid fossa
- Examiner places fingers on each side of the patients mouth
- Extraoral method
- Examiner applies thumbs to bony prominence over the cheek bone, below the zygomatic arch
- Examiner wraps fingers behind the angle of the jaw
- Ipsilateral side
- Examiner applies posterior/downward force with thumb against the anteriorly displaced manibular condyle
- Contralateral side
- Examiner applies posterior force with thumb against the normal mandibular condyle to stabilize it
- Examiner pulls the contralateral jaw angle forward with curled fingers
- Rotates the opposite displaced Mandible into position
VII. Management: Post-reduction
- Avoid extreme mouth opening (e.g. Yawning)
- Soft diet for first 2 weeks after reduction
- NSAIDs for pain
- Anticipate healing over following 1-2 weeks
- Consider soft Cervical Collar to prevent extreme mouth opening
- Follow-up with ENT or orofacial surgery
VIII. Complications
- Failed reduction (e.g. interfering articular cartilaginous disc)
- Surgical intervention may be needed in some cases
- Human Bite to examiner
- Injury to loose Dentition or dental hardware
IX. References
- Gibbons (2018) Crit Dec Emerg Med 32(8): 13
- Ramos and Schmidt (2020) Crit Dec Emerg Med 34(3): 16-7
- Wu in Majoewsky (2012) EM:Rap 12(11): 11
- Chaudhry in Kulkami (2012) Medscape EMedicine: Mandible Dislocation