Landmarks for Positioning and Local Anesthesia to Improve Success and Experience in Reduction of the Dislocated Temporomandibular Joint

Background

Anterior dislocation of the temporomandibular joint (TMJ) occurs when the condylar head slips out of the glenoid fossa and is locked anterior to the articular eminence. Dislocation typically occurs in the setting of wide mouth opening and increased ligament flexibility, but trauma or anatomical variations of the condyle and articular eminence may contribute as well. In cases of muscle spasm following dislocation, local anesthetic, or sedation can be used to relieve muscle tension and reduce pain, thus facilitating successful TMJ reduction.

Discussion

An overview of commonly used reduction techniques is presented, including anterior, posterior, and alternative approaches. This paper additionally describes an algorithm for positioning of the provider, the patient, and the room to optimize the vectors of force application during reduction of the anteriorly dislocated TMJ. Previously undescribed detail when using an intraoral, posterior approach is highlighted, with special attention paid to aligning the provider's elbows with the patient's maxillary molars. For adjunctive use of local anesthetic, providers can locate the joint space by first indentifying the root of the zygomatic arch and then redirecting the needle inferiorly to a depth of roughly 25 mm from the skin. Additionally, one can inject directly into the masseter and temporalis muscles. Procedural sedation may also be used, with an anecdotal preference for midazolam, fentanyl, and propofol.

Conclusion

Multiple reduction techniques are compared, discussing the advantages and disadvantages of each. A novel decision-making algorithm is offered, detailing positioning, approach selection, use of local anesthesia, sedation, and aftercare instructions.