Background

Acute nontraumatic temporomandibular joint (TMJ) dislocations are uncommon presentations in the ED that occur after excessive mouth opening. Common circumstances include laughing, yawning and dental extraction. The most common TMJ dislocation is the anterior form and reduction can be labor intensive, protracted and typically requires procedural sedation.

Clinical Question

Can a novel, hands-free technique (described below) result in a high rate of mandible reduction after non-traumatic dislocation?

Population

Adult subjects (> 18 years of age) with atraumatic TMJ dislocation

Intervention

Hands-free, “Syringe technique"

Outcomes

Primary: Successful reduction
Secondary: Reduction < 1 minute

Design

Prospective, observational study using a convenience sample of patients

Excluded

Traumatic injuries

Primary Results

  • Screen Shot 2016-04-21 at 4.48.29 PM

    The “Syringe Technique”

    31 patients with anterior dislocations recruited (20 women and 11 men)

  • Dislocation mechanism
    • Chewing n=19
    • Yawning n = 8
    • Talking/laughing n = 3
    • Dental visit n = 1
  • 9 patients with repeat dislocation

Critical Findings:

  • Successful reduction: 97% (30/31)
  • Successful reduction < 1 min: 77% (24/31)
  • Unsuccessful reduction in edentulous woman who was unable to effectively grasp the syringe with her gums

Limitations

  • Non-consecutive patient recruitment (convenience sample)
  • Single-center study decreasing external validity
  • Originally, traumatic TMJ dislocations were included but the study group found a very high failure rate in this group and post-data collection excluded this group
  • All of the patients in this series had anterior dislocations. This technique may not be successful in lateral or posterior dislocations

Author's Conclusions

“We describe a novel technique for the reduction of the acutely nontraumatic TMJ dislocation in the ED. It is simple, fast, safe, and effective.”

Our Conclusions

The “syringe technique" for TMJ dislocation reduction is cheap and simple. The data here shows high efficacy in a short period of time for atraumatic, anterior dislocations. Additional investigation in other centers would be useful in demonstrating reproducability of these results.

Potential Impact To Current Practice

This approach represents an additional option for TMJ dislocation reduction in the ED. Because it is simple and does not require sedation or parenteral medications, it is and excellent option for resource limited environments.

Bottom Line

The “syringe technique" appears to result in rapid reduction of TMJ dislocations in the majority of patients without requiring parenteral medications in this small observational study.

Read More

EM Lit of Note: TMJ Dislocations: A Better Mousetrap?

Core EM: Podcast 47.0 – TMJ Reduction