Jaw Dislocation: Understanding Luxation, Subluxation, Causes, Symptoms, and Treatment

Will jaw relocate itself?

A truly dislocated jaw, known as a luxation, generally will not relocate itself due to biomechanical factors and muscle spasms, requiring immediate medical intervention. However, a partial dislocation, or subluxation, may occasionally reduce spontaneously.

Understanding Jaw Dislocation (Luxation) vs. Subluxation

To understand whether a jaw can relocate itself, it's crucial to differentiate between a complete dislocation (luxation) and a partial dislocation (subluxation) of the temporomandibular joint (TMJ).

• Luxation (Complete Dislocation): This occurs when the condyle (the rounded end of the mandible, or lower jawbone) completely displaces from its normal position within the glenoid fossa (a socket in the temporal bone) and moves beyond the articular eminence. In this state, the jaw is "locked" open, and the individual cannot close their mouth.
• Subluxation (Partial Dislocation): This is a less severe form where the condyle moves out of its normal position but then spontaneously returns. It might involve the condyle momentarily slipping over the articular eminence without becoming fully trapped. Individuals might experience a "popping" or "clicking" sensation, and the jaw may feel momentarily "stuck" before returning to normal function.

Anatomy of the Temporomandibular Joint (TMJ)

The TMJ is a complex synovial joint that connects the mandible to the skull. Key structures include:

• Mandibular Condyle: The part of the lower jaw that articulates with the skull.
• Glenoid Fossa: The concave depression in the temporal bone where the condyle rests.
• Articular Eminence: A bony protrusion anterior to the glenoid fossa, which the condyle must pass over during wide jaw opening.
• Articular Disc: A small, oval-shaped piece of cartilage that acts as a shock absorber and facilitates smooth movement between the condyle and fossa.
• Joint Capsule and Ligaments: These fibrous tissues surround and stabilize the joint, limiting excessive movement.
• Masticatory Muscles: Muscles such as the masseter, temporalis, and pterygoids are responsible for jaw movement.

Why a Dislocated Jaw Doesn't Self-Relocate

When a true luxation occurs, the mandibular condyle typically moves forward (anteriorly) and superiorly, getting caught in front of the articular eminence. Several factors prevent spontaneous relocation:

• Anatomical Obstruction: The condyle becomes trapped anterior to the articular eminence, making it physically difficult to slide back into the glenoid fossa without external manipulation.
• Muscle Spasm: The powerful masticatory muscles, particularly the masseter and temporalis, immediately go into protective spasm. This involuntary contraction pulls the jaw upwards and forwards, further locking the condyle in its displaced position and resisting any attempt at self-reduction. The more the individual tries to close their mouth, the more these muscles spasm, exacerbating the problem.
• Joint Capsule and Ligament Tension: The stretched joint capsule and ligaments become taut, creating additional resistance to the condyle returning to its anatomical position.

When Self-Relocation Might Occur (Subluxation)

While a true luxation rarely self-relocates, a subluxation can and often does. This is because:

• The condyle does not fully bypass or become trapped anterior to the articular eminence.
• Muscle spasms are typically less severe or transient, allowing the condyle to slide back into the fossa.
• The individual may have hypermobility of their TMJ, meaning their ligaments are more lax, allowing for greater range of motion but also a propensity for subluxation.

Causes of Jaw Dislocation

Jaw dislocations can be caused by a variety of actions that involve excessive or prolonged mouth opening:

• Wide Yawning: The most common cause, especially in individuals with hypermobile joints.
• Trauma: A direct blow to the jaw or face.
• Dental Procedures: Prolonged mouth opening during dental work (e.g., extractions, root canals).
• Vomiting: Forceful emesis can sometimes lead to dislocation.
• Eating: Taking a large bite of food.
• Medical Procedures: Intubation or laryngoscopy.

Symptoms of Jaw Dislocation

Recognizing the symptoms of a dislocated jaw is crucial for prompt action:

• Inability to Close the Mouth: The most prominent symptom, with the jaw fixed in an open position.
• Severe Pain: Intense pain in the TMJ region, often radiating to the ear or temple.
• Malocclusion: The teeth do not align properly.
• Speech Difficulty: Trouble speaking clearly.
• Drooling: Due to inability to close the mouth and swallow saliva.
• Facial Asymmetry: The jaw may appear shifted to one side.
• Protrusion of the Jaw: The lower jaw may appear to stick out.

Immediate Actions and Medical Intervention

If you suspect a true jaw dislocation, do not attempt to self-relocate it. Attempting to force the jaw back into place without proper training can cause further injury, including damage to the joint structures, nerves, or blood vessels.

• Seek Immediate Medical Attention: A dislocated jaw is a medical emergency. Go to an emergency room or urgent care clinic as soon as possible.
• Support the Jaw: While awaiting medical help, gently support the jaw with your hands to minimize movement and discomfort. Avoid any forceful movements.
• Avoid Eating or Drinking: Do not try to consume anything as it can worsen the situation.

Professional Relocation Techniques

Healthcare professionals, typically physicians or oral and maxillofacial surgeons, use specific techniques to manually reduce a dislocated jaw. These often involve:

• Patient Positioning: The patient is typically seated, with their head supported.
• Manual Reduction: The clinician places their thumbs on the occlusal surfaces of the lower molars and their fingers under the chin, then applies downward and backward pressure to disengage the condyle from the articular eminence, followed by a gentle upward and forward motion to guide it back into the glenoid fossa.
• Pain Management: Sedation or local anesthesia may be used to relax the muscles and minimize pain during the procedure.

Prevention and Management

For individuals prone to jaw dislocations or subluxations, preventative measures are important:

• Avoid Extreme Mouth Opening: Be mindful when yawning, eating large foods, or during dental procedures.
• Support the Jaw During Yawning: Place a fist under your chin to limit the extent of opening.
• TMJ Exercises: A physical therapist or kinesiologist can recommend specific exercises to strengthen the muscles around the TMJ and improve joint stability.
• Night Guards/Splints: For individuals with bruxism (teeth grinding) or clenching, a custom-fitted oral appliance can help reduce stress on the TMJ.
• Address Underlying Issues: If hypermobility or other TMJ disorders are present, work with a healthcare professional to manage these conditions.

Complications of Untreated Dislocation

Leaving a true jaw dislocation untreated can lead to serious complications:

• Chronic Pain: Persistent pain in the jaw, face, and head.
• Recurrent Dislocation: Increased likelihood of future dislocations due to stretched ligaments and weakened joint structures.
• TMJ Dysfunction: Long-term problems with jaw movement, clicking, popping, and locking.
• Osteoarthritis: Accelerated wear and tear on the joint cartilage.
• Ankylosis: In rare, severe cases, the joint may fuse, leading to permanent immobility.

In conclusion, while a jaw subluxation might spontaneously resolve, a true luxation requires prompt medical attention. Understanding the anatomy and biomechanics of the TMJ underscores why professional intervention is critical for safe and effective relocation, preventing further injury and long-term complications.