Dislocation may occur in association with yawning or dental examination, for example.
The dislocation is usually unilateral but may be bilateral.
In some patients, the dislocation may recur.
If the dislocation is caused by an injury, for example a blow in the face or falling over, a fracture should always be suspected first, and the patient should be referred as an emergency case to a specialist in oral and maxillofacial surgery for an assessment.
The earlier reposition is attempted, the better it usually succeeds.
Symptoms
The patient cannot shut the mouth normally.
Maxillary and mandibular teeth do not align with each other, like earlier.
The mandibular condyle is usually displaced to lie anterior to the articular eminence of the temporal bone, leading to an abnormally anteriorly positioned mandible.
The tip of the jaw deviates to the opposite side in unilateral dislocation.
For differential diagnosis, it is important to distinguish between a possible fracture and problems related to the temporomandibular joint disk. In case of an injury, facial swelling and pain are often present, in which case a fracture is possible. In problems related to the disk, the mouth can be closed, but dental occlusion feels different and the patient has pain in the area of the temporomandibular joint.
Treatment
Place the patient in a sitting position with back straight. An assisting person, if available, stands behind the patient supporting his/her head. The assistant may try to relax the masticatory muscles of the patient by gently massaging his/her cheeks.
Press your both thumbs as deep as possible behind the last molars inside the mouth of the patient. Support the mandible with the rest of the fingers from the outside. Press the jaw gently straight downwards and, as the patient relaxes, attempt to lift the tip of the chin upwards while still pressing the posterior teeth downwards.
If repositioning is successful, instruct the patient to limit opening of the mouth to 2 cm during the following 2 weeks, in order to avoid recurrence of the dislocation.
If repositioning is unsuccessful, refer the patient as an emergency case to an oral and maxillofacial surgery unit.
If the dislocation recurs frequently consult an oral and maxillofacial surgeon.
If a fracture is suspected, repositioning must not be performed.