What is Mandible Dislocation (Jaw dislocation)?
The temporal mandibular joint (TMJ) dislocation, also known as mandibular dislocation, is a condition where the connection – or condyle – between the jawbone and the temporal bone in your skull shifts out of place. This displacement could occur on both sides or just one side of your jaw, and it can move forward, backward, upward, or sideways. To understand and treat this condition, it’s necessary to know the structure of the TMJ.
In a healthy joint, the jawbone fits neatly into a cavity – or glenoid fossa – on the temporal bone. This joint is unique because it has a thick disc of connective tissue that allows it to both swing like a door and slide like a drawer. In keeping your jaw shut, muscles like the masseter, medial pterygoid, and temporalis are used. On the other hand, the lateral pterygoid muscle is responsible for opening your jaw.
Firm bands of tissue, or ligaments, provide support to the joint. These include the temporomandibular, sphenomandibular, and capsular ligaments. Additionally, the joint gets its blood supply from a branch of the external carotid artery known as the superficial temporal branch. Feeling in the joint is supplied by the mandibular branch of the trigeminal nerve, specifically through the masseteric and auriculotemporal nerves.
What Causes Mandible Dislocation (Jaw dislocation)?
Dislocation of the temporal mandibular joint (TMJ), or jaw joint, can happen due to several reasons, some of which aren’t related to any injury or trauma. These non-traumatic causes often involve any action that forces the mouth to open wide, like yawning, having a seizure, or even excessive chewing. Certain underlying anatomical reasons, like loose ligaments, unusual structure, or disorders involving connective tissue, can also contribute.
Activities that we often consider normal, such as laughing, yawning, singing, vomiting, or kissing, can cause this dislocation too. Situations that can cause severe and involuntary muscle contractions, like tetanus, and certain side effects of medicines can also be non-injury related causes. Additionally, there are certain medical procedures, which involve the mouth and throat, such as dental treatments, intubation, bronchoscopy, and laryngoscopy, that can cause jaw dislocation.
Physical trauma to the face, however, remains one of the most common reasons for the dislocation of the TMJ.
Being aware of risk factors for TMJ dislocation can help in identifying the potential causes for the dislocation and the chances of it happening again. These risk factors include having had a dislocation before, structural or anatomic issues, disorders that affect stability (e.g., Marfan syndrome, Ehlers-Danlos syndrome, muscular dystrophy, orofacial dystrophy), neurodegenerative or neurodysfunctional disorders (like Huntington disease, multiple sclerosis or epilepsy), getting older, and changes in a patient’s dentition or arrangement of teeth.
Risk Factors and Frequency for Mandible Dislocation (Jaw dislocation)
Mandibular dislocation, or dislocation of the jaw, doesn’t happen very often. It doesn’t favor any particular age group or gender. However, because men tend to experience more facial injuries, they might have a slightly higher chance of dislocating their jaws due to trauma. The most common type of jaw dislocation is the anterior dislocation, which typically happens due to non-injury related causes. Other types of dislocations, like the posterior, lateral, and superior dislocations, are even less common. It’s also worth noting that it’s more common for both temporomandibular joints (TMJ) of the jaw to be dislocated at the same time than just one side.
Signs and Symptoms of Mandible Dislocation (Jaw dislocation)
Acute dislocation, a painful condition, might show as discomfort in the preauricular area (the area just in front of the ear), struggling to close the mouth, unclear speech, and drooling. The situation might be brought on by a specific event such as trauma, yawning, laughing, vomiting, seizures, or even dental procedures. Some medications are linked to a higher likelihood of jaw dislocation, these include haloperidol, phenothiazines, and thiothixene. People with neurodegenerative or connective tissue disorders like Marfan syndrome, Ehlers-Danlos syndrome, muscular dystrophy, multiple sclerosis, Huntington disease, Parkinson disease, epilepsy may have increased risk of dislocation as well.
When a physical exam is conducted on a person with acute dislocation, there might be tenderness and a palpable indentation at the TMJ location, which is near the ear. Their jaw might be off-kilter, and the mouth may stay slightly open. The health provider will check to see if the dislocation affects one side of the jaw or both. With a dislocation on both sides, the person’s jaw will be middle-positioned, open, and locked. If the dislocation is one-sided, the jaw will lean to that side. With a superior dislocation, there’s usually a noticeable bulge in the preauricular and temple areas of the face. It’s crucial to test the trigeminal nerve (fifth cranial nerve), facial nerve (seventh cranial nerve), and vestibulocochlear nerve (eighth cranial nerve) during a superior dislocation, as these nerves might be impacted.
Testing for Mandible Dislocation (Jaw dislocation)
The diagnosis of a dislocated jaw typically relies on the patient’s history and a physical exam, rather than any imaging. However, in cases where the cause of the dislocation isn’t clear, or there’s a concern of further damage like a fracture, imaging tests can be used. A computed tomography (CT) scan is the ideal imaging test because it can assess the type of dislocation and identify any associated fractures.
X-rays and panoramic jaw radiographs (a type of X-ray that provides a broad view of the entire jaw) can be useful too, but they have some limitations due to overlapping spine views. Imaging should be done before any attempt to realign the jaw is made, to check for fractures. An MRI can also be used to examine the joint capsule and surrounding ligaments, though it’s usually saved for chronic repeated dislocations or complications like bone death, bone infection, or false joint formation.
Adults who experience a dislocation not caused by trauma and who have no signs of fracture during a physical exam, can have their jaw realigned without needing imaging first.
It’s important to note that imaging tests should be done after jaw realignment because a fracture can occur during the forceful manipulation of the jaw needed for realignment.
Usually, there’s no need for initial laboratory testing for an isolated jaw dislocation. However, women of childbearing age should take a pregnancy test before getting any imaging done, to ensure the safety of any potential pregnancy.
Treatment Options for Mandible Dislocation (Jaw dislocation)
Before reaching the hospital, no universal procedures exist for helping someone with a dislocated mandible, or jawbone. The decision to take someone to the hospital hinges on the patient’s stability and other contributing factors to the injury, such as trauma or shock. If the patient’s breathing isn’t affected, they can be transported to the hospital.
In the emergency department, medical professionals should first focus on maintaining the patient’s airway, breathing, and circulation. A comprehensive patient history will be taken, including any risk factors for a jaw dislocation. If physical examination and imaging suggest a fracture or a long-standing dislocation, specialists such as oral and maxillofacial surgeons might be consulted. Severe fractures or dislocations, or patients with multiple injuries may need to have their jaw realigned in an operating room.
To ease the patient’s pain and anxiety, sedatives like midazolam and fentanyl are recommended. Propofol, a short-acting sedative, is also helpful for jaw reduction. Local anesthetics and nerve blocks can be used to lessen pain and muscle spasm, either in conjunction with sedation or on its own.
There are both intraoral (inside the mouth) and extraoral (outside the mouth) techniques to reset a dislocated jaw. For safety, providers’ fingers can be protected during intraoral techniques using rolled gauze, gloves, and tongue depressors.
Several specific techniques include the bimanual method, where the provider pushes the jaw downwards and backwards to guide it back into place; the wrist pivot method, where the provider uses upward pressure beneath the chin and downward pressure on the lower back teeth; the recumbent technique, where the patient lies down and the provider performs similar procedures to the bimanual method; the gag reflex method, which stimulates the depressor and protruding muscles to flex the jaw back into place; the syringe method, where a syringe can be used between the upper and lower teeth to encourage the jaw to return to its correct position gradually; and the external approach, where the provider manipulates the outside of the jaw to guide it back into place.
In certain situations, patients may need to be referred to oral and maxillofacial surgery. These might include instances of chronic dislocation, dislocation with attached fracture, an open dislocation, repeated past dislocations, or dislocations that haven’t been able to be reset with closed reduction techniques.
Other non-surgical treatment options include treatments like injections of botulinum toxin to weaken the muscle and prevent further dislocations, or injections of the patient’s own blood into the joint space to cause beneficial inflammation and scarring. Both can be repeated as needed to help reduce future dislocations.
What else can Mandible Dislocation (Jaw dislocation) be?
If a person has experienced facial trauma, it’s crucial to quickly identify if they have suffered a broken jaw or specifically a fracture in the condylar – the rounded part on the end of the jawbone. Often, these type of injuries can occur together with a dislocated jaw. This means the jawbone has moved out of its normal position. When dealing with a dislocation caused by an injury, doctors will use imaging techniques, such as X-rays, to check for any fractures.
Interestingly, some infections can also show symptoms that look similar to a dislocated jaw. These include conditions like epiglottitis (an inflammation of the flap at the base of the tongue), a retropharyngeal abscess (a deep tissue infection at the back of the throat), or a peritonsillar abscess (a pocket of pus near the tonsils). In these cases, people often experience drooling, difficulty opening the mouth fully (known as trismus), and pain in the throat or neck.
Therefore, it’s key to thoroughly check the patient’s mouth and throat area, and ask about their medical history. This is because the treatment methods for an infection and a dislocation are very different. Other conditions that might be mistaken for a jaw dislocation include TMJ dysfunction and acute closed locking of the TMJ meniscus – conditions that affect the joint connecting the jaw to the skull. Conditions causing muscular spasms, like tetanus, could also make it hard for the patient to open their mouth normally. So, the medical history of the patient, physical examination, and imaging tests are important factors in distinguishing between these different conditions and a dislocated jaw.
What to expect with Mandible Dislocation (Jaw dislocation)
The outlook for isolated dislocations of the lower jaw is generally positive, but it can vary depending on the type of dislocation. Frontward (anterior) dislocations often have the best outcomes, while sideways (lateral) dislocations are usually linked with fractures and need open surgery to fix. Long-term complications are uncommon if a dislocation is appropriately treated right away.
However, even with proper treatment, some acute (sudden and severe) dislocations may be more likely to happen again in the future.
Possible Complications When Diagnosed with Mandible Dislocation (Jaw dislocation)
If you repeatedly dislocate your jaw, this can become a chronic problem and may even damage the ligaments and joint capsule, leading to joint disease. The external ear canal can be damaged if there’s dislocation both towards the back and the top and this could lead to hearing loss. Nerve damage can also happen to the facial nerve (also known as the seventh cranial nerve) and the hearing and balance nerve (also known as the eighth cranial nerve). There’s also a risk of injury to blood vessels which can damage the external carotid artery (the artery that supplies blood to the face and neck) or cause a bruise in the brain.
Complications can also arise after a medical procedure to correct the dislocation. A fracture, ligamentous injury or avulsion fracture (where a piece of bone gets torn off) may occur due to the force applied to the jaw during this procedure.
When botulinum toxin is injected as a treatment, complications such as bleeding, injection into a blood vessel, spreading into nearby tissues, difficulty swallowing or toxin-induced impairment of velopharyngeal function (which is important for speech) may occur. Patients with an allergy to botulinum toxin and a muscle weakness disorder called myasthenia gravis should not undergo this treatment.
Preventing Mandible Dislocation (Jaw dislocation)
After a successful procedure to adjust a misaligned part of the body, patients can usually leave the hospital. To ensure the success of the procedure and prevent it from recurring, it’s advised that patients either wear a head-chin bandage or a sturdy neck brace. For one to three weeks after the procedure, patients should avoid opening their mouth too wide (more than 2 cm).
It’s also recommended to stick to a diet consisting mainly of soft foods for a couple of days up to two weeks. When yawning, they should take care to support their jaw with their hand. Using a cushioned neck brace might provide additional support and help restrict wide mouth opening. To relieve any pain and swelling experienced after the procedure, patients could consider taking non-steroidal anti-inflammatory drugs (NSAIDs).
Finally, the patient should plan a follow-up visit with an ear, nose, and throat specialist (often referred to as an ENT) or a dental surgeon who specialises in jaw and facial surgery (an oral maxillofacial surgeon) within two to three days of their procedure.
