– Jaw dislocation: role of the temporomandibular joint
– Causes of jaw dislocation
– Symptoms of jaw dislocation
– Dislocation of the jaw: treatment
Jaw dislocation, or temporomandibular joint (TMJ) dislocation, is a fairly common trauma. Let’s see how this powerful joint can dislocate, discover what the symptoms of a jaw dislocation are, and what treatment is available.
Jaw dislocation: role of the temporomandibular joint
The temporomandibular joint (TMJ), located 1.25 cm in front of the earlobe, is one of the most complex joints in the body. Indeed, it performs a precise movement when it is mobilized. In addition, it is subjected to enormous pressure every day since it allows chewing.
In order to understand the phenomenon of dislocation, it is important to know that the temporomandibular joint (TMJ) is the joint between the ascending branch of the mandible (or lower jaw) at the condyle and the temporal bone that belongs to the skull at the glenoid.
A meniscus (or disc) exists between these two articular surfaces (like in the knee). It prevents the bones from rubbing directly against each other and distributes the pressure exerted during chewing. In addition, the powerful muscles that open and close the mouth stabilize the TMJ.
Normally, when the mouth is opened, the condyle tilts into the glenoid and then slides forward. In this case, we speak of physiological subluxation (which is normal). On the other hand, a total dislocation occurs if the condyle leaves its housing and remains blocked in front.
Causes of jaw dislocation
The leading cause of jaw dislocation is opening the mouth a little too much. This is, for example, the case during:
– dental care;
– an attempt to eat a huge sandwich…
Very often, excessive muscular tension is the cause. They can indeed keep the meniscus blocked forward, and these tensions can be due to stress and bruxism. It can also be due to trauma (fall, punch, etc.).
However, generally speaking, for this to lead to a real dislocation, the person must have significant muscle spasms (Sadam syndrome, for example) or abnormalities such as ligament hyperlaxity (the ligaments that are supposed to hold the condyle in place are in this case too loose, too distended), which is common in young women.
Good to know: the TMJ can be a victim of osteoarthritis and even be affected in case of rheumatoid arthritis.
Symptoms of a dislocated jaw
Jaw dislocation is not necessarily painful when it occurs. However, it does cause a locking of the lower jaw (mandible). It is essential to distinguish true jaw dislocations from meniscal dislocations.
Generally, in the first instance, a dislocation results in a popping sound due to the condyle and the meniscus returning to its normal position (reducible disc displacement). This is a simple, painless meniscal dislocation, which is the most common.
A true dislocation of the jaw is a much rarer phenomenon:
– The person with a TMJ dislocation finds it impossible to close the mouth (irreducible disc displacement, i.e., the meniscus does not spontaneously replace itself).
– No clicking is heard, and an intense pain in the jaw will appear.
– The pain is mainly due to the significant muscular tensions (remember that the muscles involved are powerful).
This lock of the jaw leads to many inconveniences: difficulties in speaking, the impossibility of eating, a tendency to drool (since it is impossible to close the mouth), etc. These characteristic symptoms are enough to bring the patient to an emergency consultation.
Good to know: an untreated dislocation of the jaw will prematurely wear out the articular surfaces and favor the occurrence of temporomandibular osteoarthritis.
Jaw dislocation: treatment
The treatment of jaw dislocation is to reduce the dislocation with the help of manipulation. The sooner this procedure is performed after the dislocation, the easier it is to perform (mainly because the muscles are not tense and spasmed, which would complicate the maneuver considerably).
The principle is simple. The practitioner will:
– place his thumb in the patient’s mouth to have support on the lower molars;
– grasp the angle of the mandible and the ascending ramus with his index and middle fingers;
– Apply downward and forward pressure to release the condyle;
– replace the condyle in its seat by bringing it back and up.
This manipulation takes only a few seconds and is performed without anesthesia because it is generally not very painful. It can be performed by a doctor who knows how to do it, by a physical therapist, or even by an experienced dentist or orthodontist. It is also possible to call upon an osteopath who can bring forward a more global action by treating the muscular tensions at the cervical level and performing cranial osteopathy.
Some doctors may want to place a bandage to prevent the patient from opening his mouth too much. Set for 5 days, it allows the joint capsule of the TMJ to heal by limiting its movements. The patient is also advised to prefer liquid food and not to open the mouth too wide for a short week.
The origin of any excessive muscle tension must also be taken into account, and solutions must sometimes be implemented to learn how to manage stress.
It is also possible to correct jaw dislocations with the help of an occlusal device made by an orthodontist. This consists of wearing an occlusal elevation tray at night and a mouth guard over the upper teeth.
This device can reduce muscle tension and allow the TMJ to reposition itself properly. However, it takes two to four weeks for the treatment to be effective and a few more months for lasting results.
On the other hand, if the pain is not of muscular origin but purely articular, this treatment is ineffective.
If the origin of the problem is articular, or if the joints are too damaged, surgical intervention is recommended:
– either a temporomandibular arthroscopy in order to perform a joint lavage to “free” the meniscus;
– or a temporomandibular arthrotomy which consists in surgically opening the joint and, depending on the case:
◦ to put the meniscus back in place,
◦ to remove the disc and replace it with a prosthesis (if it is too worn),
◦ to eliminate irregularities in the joint surfaces.