Dislocated Jaw: Causes And Symptoms

Overview

A dislocation is defined as the loss of the articular relationship between two bones, which, in the case of temporomandibular joint (TMJ) dislocation, affects the articular fossa of the temporal bone and the condyle-disk complex.¹ The dislocation of the jaw is a relatively common injury that affects 5% of the population (thus 1 out of 20 people) at some point in their lives.¹ Therefore, it is likely that either you know someone who has had a dislocated jaw or suffer from it yourself. If you want to know more about its causes or to learn what the symptoms are to identify it, keep reading!

Jaw dislocation can be both unilateral (one side) or bilateral (both sides). It can be displaced forwards, backwards, or to the sides.² Anterior (forward) dislocations are the most common type and are associated with the highest risk of recurrence. 

Causes of a dislocated jaw²

A dislocated jaw is usually due to facial trauma, which can be because of a blow (e.g., in a car accident) which is the most common cause of posterior (backwards) TMJ dislocation.

TMJ dislocation can also be caused by simply over-opening your mouth excessively while, for example, yawning, singing, laughing, or during medical procedures like dental surgery (e.g., for getting a dental implant or removing your wisdom teeth) or a laryngoscopy. In fact, this is the main cause of anterior TMJ dislocation. Apart from the mentioned examples, this excessive opening can also be triggered by muscle spasms due to epileptic seizures, dystonic reactions, which are characterised by involuntary contractions of muscles (e.g., due to tetanus), and drug-induced movement disorders. Specifically, in the case of anterior and posterior. TMJ dislocation can also have underlying anatomic causes such as generalised ligamentous laxity, which is characterised by an increased range of TMJ joint motion,³ connective tissue disorders (e.g., Ehlers Danlos syndrome),⁴ and abnormal facial features (e.g., misaligned jaw, diminished articular eminence, and uneven jaw growth).

Signs and symptoms of a dislocated jaw²

The symptoms and signs of dislocated jaw that have been reported include:

• Inability to close the mouth (referred to as “open lock of the jaw” or locked jaw)⁵
• Drooling
• Difficulty with speech and chewing
• Pain: severe preauricular (TMJ pain) and local facial pain caused by the stretch of the ligaments and jaw muscles. This can cause neck pain and ear pain too
• Signs such as a palpable preauricular depression and garbled speech

Management and treatment for a dislocated jaw

Usually, patients are able to reduce the dislocation by themselves. In this case, it is referred to as a subluxation. If an interventional reduction is required, it is known as luxation.⁵ Interventional reduction is usually carried out in Accident & Emergency under anaesthesia or sedation and is based on pushing the jaw downward and backwards to its normal position.⁶ These nonsurgical reductional methods include:^1,2 

• The traditional or hippocratic method: the most common technique used for TMJ reduction. For this method, doctors place their thumbs over the patient’s lower molar teeth and apply pressure on them to push the mandible downward and backwards
• The wrist-pivot technique: similar to the traditional method. The doctor places the thumbs under the chin and the fingers on the lower molars and then applies both upward and downward pressure. After this, the wrist is pivoted forward so that the mandible is moved downward and posterior
• The combined ipsilateral staggering technique⁸ which involves a combination of the above
• The Awang’s gag reflex method: mainly used in chronic recurrent dislocations, which last longer than 72 hours. In this technique, doctors stimulate the gag reflex by touching the pharynx and the soft palate. This triggers different muscles that help to reduce the dislocation 
• The use of autologous blood transfusions: the TMJ joint space is drained and then the patient’s blood is injected. This triggers an inflammatory response decreasing compliance of the jaw joint
• Botulinum toxin A: the injection of this toxin weakens some facial muscles and prevents recurrent dislocation

The problem with these techniques is first of all, that those implying the use of force might lead to damage of the mandible, and secondly, that it has been suggested that nonsurgical approaches such as these are not effective enough as after performing this interventional reduction, many patients have their jaw dislocated again. In contrast, open and arthroscopic interventions do reduce significantly the rate of reoccurrence.⁶

Diagnosis

First of all, a physical examination is conducted. For this, doctors examine the preauricular area, which in jaw dislocation is depressed, and palpate different jaw muscles searching for tenderness and sustained contraction and over the jaw joint while the patient opens and closes the mandible.⁷  This physical examination will be useful to determine whether the jaw is dislocated or not and to evaluate if there is a concern for jaw fracture or not. Imaging tests such as X-rays or CT scans, which are basically X-ray studies that create more detailed images than X-rays do, are sometimes used when there is a concern for fracture, the diagnosis is unclear, or there has been a traumatic event to diagnose a broken jaw. However, it is not always used and can be unnecessary for diagnosing jaw dislocation. Nevertheless, it is useful for determining the associated fractures, if any, and the type of dislocation. If there is no concern for fracture after the physical exam, reduction can be performed without using any imaging test. After reduction, imaging tests must be used to ensure that an iatrogenic fracture has not occurred.

Risk factors²

Risk factors for a jaw dislocation include:

• Having a previous dislocation, as jaw dislocation is likely to be recurrent (especially if the dislocation is reduced by nonsurgical methods)
• Structural or anatomical problems
• Suffering from neurodegenerative disorders (e.g. epilepsy or Huntington’s disease) or disorders that affect stability (e.g. Ehlers-Danlos syndrome)
• Age: the older a person is, the higher the risk of suffering from a dislocation
• Changes in dentition

FAQs

How can I prevent dislocated jaw?

The main way of preventing dislocated jaw is using safety equipment (e.g., mouth guard, helmet) to protect yourself while doing activities or sports that can have a certain risk of trauma.

How common is dislocated jaw?

As mentioned, dislocated jaw affects 5% of the population (thus 1 out of 20 people) at some point in their lives.¹ In this way, dislocated jaw is a quite common injury.

When should I see a doctor?

As soon as you think that you might have a dislocated jaw, go straight to the doctor. The sooner the injury is confirmed, the sooner the dislocation will be reduced and the lower the chance of suffering from complications (e.g., recurrent and chronic mandible dislocation, nerve damage, deafness). Before arriving or on the way to the hospital, it is important to try to hold the jaw in place either with the hand or a bandage so that the damage is reduced.

Summary

A dislocated jaw is a common injury that although often caused by a blow, can also occur just by over-opening your mouth while yawning or laughing. The main symptoms are the inability to close the mouth, preauricular depression, jaw pain, and drooling. In some cases, the dislocation can be reduced by the patient themself but sometimes medical help is needed. To manage and reduce dislocation, doctors can carry out either nonsurgical or surgical procedures. There is a chance of reoccurrence, especially if previously managed nonsurgically.