Outline:  
Most of the dislocation patients are generally weak with flaccid muscles, especially in old women. The dislocation may occur as one laughs with mouth wide open, or yawns, or opens mouth widely to bite hard food or vomits violently, and so on. All these may cause mandibuar condyloid process to slip forward, exceeding the highest point of articulator eminence and being locked under the zygomatic arch anterior to the eminence, hence the dislocation. The dislocation can be unilateral or bilateral. Habitual dislocation usually happens in weak old people whose masseter and temporomandibular ligaments are extremely loose or work too early after the reduction of initial dislocation.

Major points for diagnosis  
1. The patient has a typical history of opening mouth excessively.
 
2. There is a pain in the lower jaw after the injury; the mouth can not close and saliva dribbles; the lower jaw projects; the patient can neither speak nor swallow foods; even there is dysmimia.

3. The buccal surface is flat; the condyloid process can be felt under the zygomatic arch; there are hollow, depression and slight tenderness in front of the tragus. In the case of a unilateral dislocation, the chin is inclined to the normal side. In the case of a bilateral dislocation, the chin projects directly forward.

Reduction:  
1) Intraoral reduction: The patient takes a low sitting position with his back against a wall. The operator, standing in front of the patient, puts his two thumbs, which have been wrapped up with disinfected gauze, into the patient's mouth simultaneously. Then, he presses the endmost lower teeth of both sides respectively with his two thumbs, at the same time firmly holds the angle of the lower jaw with his forefingers from outside, and firmly holds the lower jaw with the other three fingers. As pressing forcefully down with his thumbs, he tightly holds the lower jaw with the three fingers in combination with the thumbs, and pushes it downwards and backward, thus, the reduction can be achieved.
 
2) Extraoral reduction: This method can be applied to those patients with tense masseters. The operator puts his two thumbs on the patient's acupoint Xiaguan (ST 7) and after a moment of massage, squeezes and presses forcefully the condyloid process upward and backward. At this time the patient may feel sore andnumb in the two sides of lower jaw and relaxed in the masseters. Then the operator, holding up the angles of lower jaw with his thumb, index and middle fingers of both bands and the lower jaw body with his ring and little fingers, elevates the angles of the lower jaw in coordination with all fingers so that the reduction can be done.

Fixation:
Wrap up the lower jaw with a four-headed band with the four ends knotted on the patient's head respectively. The duration of fixation is 2 to 3 days. The patient is asked not to open his mouth forcefully and not to eat hard food during this period.

Functional exercise:
During and after fixation, the patient is asked to frequently practice chewing strongly in the case of closed mouth for masseter exercise.

Herbal therapy
Chinese patient medicines:
In the early stage, Huoxue Zhitong Capsule is used, 4 capsules each time and twice a day; or Yunnan Baiyao is orally given, 0.5 g each time and twice a day. In the late stage, Liuwei Dihuang Pill is orally given, 5 g each time and twice a day.

Extemal therapy:
In the early stage, Jiejing Zhentong Tincture may be externally applied on the diseased jaw; in the late stage, Huoluo Ointment may be externally applied.