Open but not closed

Introduction Patients with temporomandibular joint dislocation have an abnormal movement of the jaw, which is open and cannot be closed. When the mandibular condyle moves beyond the normal limit, the joint is concave and cannot return to the position by itself, which is the dislocation of the temporomandibular joint. Clinically, it is mostly dislocation in the front and can occur on one side or both sides. The anterior dislocation of the temporomandibular joint is often caused by a sudden opening of the mouth, such as laughing, yawning, or because of a long mouth opening. For oral or pharyngeal examination or surgery, the use of an opener is excessive, so that the condyle is removed from the joint. Located in the joint. Mainly seen in congenital dysplasia, as well as the symptoms caused by acquired trauma and other reasons, it is best to go to the hospital for detailed treatment after active treatment.

Cause

The anterior dislocation of the temporomandibular joint is often caused by a sudden opening of the mouth, such as laughing, yawning, or because of a long mouth opening. For oral or pharyngeal examination or surgery, the use of an opener is excessive, so that the condyle is removed from the joint. Located in the joint.

an examination

Related inspection

Skull flat

First, clinical manifestations

The patient developed an abnormal movement of the jaw, which was open and could not be closed. Unclear language, saliva outflow, chewing, difficulty swallowing. The mandible is extended forward and the forehead is moved downward, and the shape of the face is correspondingly long. The palpable area can be found in front of the tragus during palpation. When the unilateral anterior dislocation, the lower jaw slightly extends forward, and the midline of the ankle is biased to the healthy side.

Second, diagnosis

1, dislocation side

It can be either unilateral or bilateral dislocation.

2, the time characteristics of dislocation

When the patient is in the state of dislocation of the temporomandibular joint, the dislocation time is within two weeks, which is called acute dislocation. Those who have been more than two weeks old are called protracted dislocations. Repeated dislocation is called habitual dislocation.

3, dislocation direction

Because the articular recess forms a bony limitation on the upper and lower sides, anterior dislocation is most common. Dislocation of the other direction occurs only when an external force is applied to the lower jaw and is accompanied by an ankle fracture. The mandible is a whole, and the two joints also function as a whole. The internal displacement limitation of one side joint also helps to prevent the joint on the other side from dislocating outward, so the external dislocation of the joint only occurs when the contralateral side has a condylar neck fracture.

4, dislocation symptoms and physical symptoms

In the anterior dislocation, the condyle is located in front of the joint nodule, in front of the tragus, between the condyle and the lateral condyle of the ankle, showing a triangular depression with obvious visual and palpation. In the case of unilateral dislocation, the mandible is extended forward and deflected to the opposite side, except that the affected side of the posterior teeth may be exposed early, the remaining teeth are opened, and the face is lengthened. Other accompanying symptoms include Zhang, closed mouth, pain in the affected joint area, facial pain, chewing food, swallowing, language, and expression. Therefore, dislocation of the temporomandibular joint should be considered as a dental emergency.

A anterior dislocation without a fracture can be diagnosed by clinical alone. Dislocations in other directions are often accompanied by fractures, which must be confirmed by X-ray examination.

Differential diagnosis

In the anterior dislocation, the condyle is located in front of the joint nodule, in front of the tragus, between the condyle and the lateral condyle of the ankle, showing a triangular depression with obvious visual and palpation. In the case of unilateral dislocation, the mandible is extended forward and deflected to the opposite side, except that the affected side of the posterior teeth may be exposed early, the remaining teeth are opened, and the face is lengthened. Other accompanying symptoms include Zhang, closed mouth, pain in the affected joint area, facial pain, chewing food, swallowing, language, and expression. Therefore, dislocation of the temporomandibular joint should be considered as a dental emergency.

A anterior dislocation without a fracture can be diagnosed by clinical alone. Dislocations in other directions are often accompanied by fractures, which must be confirmed by X-ray examination.

Dislocation occurs before the structure.

Dislocation of the temporomandibular joint due to violence should be differentiated from mandibular neck and neck fractures, the midline of the jaw is biased to the affected side (when unilateral fracture), or the anterior teeth are open jaw (when bilateral fractures), There was obvious tenderness and hematoma in the neck, and the fracture line was seen by X-ray examination.

In addition, it should be noted that some people with unclear consciousness, mental illness, cerebrovascular disease and the elderly, due to joint capsule and ligament tissue and muscle relaxation and mandibular joint dislocation are not uncommon. The disease cannot exist at the same time. Psychotic drug-reactive dementia and temporomandibular joint dislocation are easier to identify, although some symptoms are similar, but the latter is accompanied by mandibular joint dysfunction, occlusion relationship is disordered, X-ray shows that the condyle protrudes out of the joint socket, the diagnosis is not difficult.

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