Mandibular dislocations can be extremely difficult to reduce at times.
The classic method of reducing a mandible dislocation is for the provider to wrap his thumbs in guaze (to prevent them from being bitten), and while placing his thumbs bilateraly as far posterior on the mandible as possible, he applies downward, and then posterior pressure to reduce the dislocation.
Significant muscle spasms can result from the dislocation, requiring procedural sedation, but even with sedation it can be very difficult if not impossible to reduce the mandible.
Dr. Cheng's article, referenced below, describes a new technique, where the provider use both of his thumbs to press down on a single side of the mandible posterior until the side reduces.
For a bilateral dislocation, the technique would be to reduce one side and then the other.
Some authors also recommend using rolled guaze to hold the patient's mouth shut so that they do not inadvertantly dislocate their jaw a second time if they happen to yawn while awakening from their sedation.
References
Cheng D. Unified hands technique for mandibular dislocation. J Emerg Med. Mar 19 2009.
