The acute temporal-mandibular joint dislocations represent a condition capable of instilling great apprehension in the patient who suddenly finds himself “blocked” and unable to close his mouth. As a result, clinical management, i.e., the reduction of dislocation by the dentist, is often very difficult. One can also imagine how such a maneuver could, in turn, frighten, especially the younger clinicians who are called upon to assess the situation quickly and ensure a benefit to the patient in an equally short period of time.
Anterior dislocations of the articular disc, mono or bilateral, may affect 5% of the population over the course of their lives and may occur as a result of prolonged opening (i.e., typically at the margin of dental treatments), traumatic events or, trivially, physiological acts such as yawning. An individual may be predisposed to dislocation of the TMJ due to laxity of the relative ligaments, spasm or muscular incoordination.
Local anesthetic in joint dislocations therapy
Recently, an interesting report, produced by Woodall and colleagues and published in the Journal of Stomatology, Oral, and Maxillofacial Surgery, described a procedure aimed at achieving pain reduction and muscle relaxation through the use of local anesthetic. The rationale is to reduce the motor activity of the pterygoid muscles, which physiologically play the role of initiators of the elevation and protrusion of the mandible. This facilitates the subsequent phase of real reduction, in which the condyles are brought back inferiorly and posteriorly.
The technique involves the administration of local anesthetic, for example, lidocaine 2% with adrenaline 1:80000, in a pit infratemporal, directing the needle laterally to the tuberosity of the maxilla. In this region, both pterygoid muscles are inserted. The bone margins that delimit the infratemporal fossa are represented by the posterolateral maxilla, that is, the lateral pterygoid process, the mandibular branch, and the tympanic part of the temporal bone. The mandibular nerve, which is responsible for the motor innervation of the entire masticatory musculature, and, in addition to it, the internal maxillary artery and the pterygoid venous plexus run through the area. It would, therefore, be subject to an important risk, especially hemorrhagic. The author, however, wanted to present the technique strengthened by decades of expertise, emphasizing how this is useful in approaching the dislocation picture without having to resort to the use of muscle relaxants, sedation or even less general anesthesia.
In truth, Chan had previously described extraoral access, passing directly through the lateral pterygoid muscle. Woodall instead proposes a new and less invasive (and, therefore, considered safe) intraoral approach. In the author’s intention, therefore, there is a reduction in the use of drugs and, even more, in the use of general anesthesia, which is consequently indicated only for cases of greater clinical complexity.