Authors: Jonathan Kobles, MD and Matthew Generoso, MD

Case: A 25-year-old female with no significant past medical history presents to the Emergency Department with right jaw pain and inability to close her mouth. She reports an episode of nausea and stomach cramping and a sensation that she was about to vomit. After running to the bathroom and attempting to vomit, she felt a clicking sensation in her jaw (worse on the right side) and afterward was unable to close her mouth. She states this has never happened to her before, and she denied any direct trauma to her face, jaw, or mouth. * On exam, her mouth is held open and she is unable to fully close her mouth. She has no significant facial swelling, and no evidence of intraoral trauma. She has mild tenderness to her right temporomandibular joint (TMJ), where she is suspected to have an anterior TMJ dislocation. * She is given 30 mg of intramuscular ketorolac and 5 mg of intramuscular diazepam. * Reduction of her anterior TMJ dislocation is attempted with both extra-oral and intra-oral manipulation, without success and with significant discomfort from the patient. Background: Temporomandibular joint (TMJ) dislocation occurs when the mandibular condyle becomes trapped anterior to the articular eminence, preventing spontaneous reduction and leaving the patient unable to close their mouth. * Most ED presentations involve acute anterior dislocations following routine activities that require excessive mouth opening, including yawning, laughing, vomiting, singing, dental procedures, or endoscopy. * Traditional reduction methods rely on provider-applied force and may require procedural sedation. The syringe technique offers a patient-driven alternative that can often be performed without sedation and may be particularly useful in patients with recurrent atraumatic dislocations. Epidemiology*** Anterior dislocations account for the overwhelming majority of TMJ dislocations encountered in clinical practice. Bilateral dislocations occur more commonly than unilateral dislocations and are frequently associated with atraumatic mechanisms. * Patients at highest risk for recurrence include those with prior dislocations, generalized ligamentous laxity, connective tissue disorders, abnormal joint anatomy, and neuromuscular conditions that alter normal jaw mechanics. * Recurrent dislocators represent the population most likely to benefit from learning the syringe technique as a future self-reduction maneuver.

Clinical Presentation: Patients typically present with an inability to close their mouth accompanied by preauricular pain, difficulty speaking, excessive salivation, and inability to chew normally. * On examination, the jaw is fixed in an open position. Bilateral dislocations generally produce a symmetric appearance, whereas unilateral dislocations often cause deviation of the mandible toward the unaffected side. * The diagnosis is usually clinical. Imaging should be reserved for patients with significant trauma, concern for fracture, atypical findings, or failed reduction attempts. Differential Diagnosis: Mandibular fractures, particularly condylar fractures, should be considered in patients with traumatic mechanisms, persistent malocclusion, facial deformity, or focal bony tenderness. * Deep neck space infections, peritonsillar abscesses, and epiglottitis may mimic TMJ dislocation by causing drooling, muffled speech, and difficulty handling secretions, though associated infectious symptoms are typically present. * TMJ internal derangement, acute dystonic reactions, and tetanus can all produce abnormal jaw positioning or restricted jaw movement and should be considered when the clinical presentation is atypical. The Syringe Technique:*Patient Selection Ideal candidates are awake, cooperative patients with an acute atraumatic anterior dislocation and no evidence of associated fracture. * The technique should generally be avoided in patients with significant facial trauma, altered mental status, inability to cooperate, or concern for mandibular fracture.

Procedure1. Place a 5- or 10-mL syringe between the upper and lower posterior molars on the affected side. 2. Instruct the patient to bite gently and slowly roll the syringe back and forth. 3. Continue until reduction occurs. 4. If the initial attempt is unsuccessful, repeat the maneuver on the contralateral side.

Mechanism* Rolling the syringe creates gradual rotational movement of the mandible while promoting relaxation of the muscles of mastication. As muscular tension decreases, the condyle...