X-ray photography: how to set the position of zygomatic arch and maxilla?

The dislocation of temporomandibular joint is that the mandibular condyle slips out of the joint and cannot be reset by itself. It can happen unilaterally or bilaterally. Acute anterior dislocation and recurrent anterior dislocation are very common in clinic. Acute anterior dislocation of mandibular joint is generally due to large opening, such as yawning, singing, biting a large hard object or nausea and vomiting. The lateral pterygoid muscle continues to contract, pulling the condyle through the joint meridians, and at the same time, the maxillary muscle reflexively contracts, which leads to the condyle breakthrough being blocked in front of the joint tubercle and unable to reset itself. In addition, when the passive opening force is too large and too strong, such as using the mouth opener, bronchoscope, esophagoscope, gastroscope, direct laryngoscope, etc. for general anesthesia tracheal intubation, the joint can be dislocated. If acute joint dislocation is not treated correctly in time, it may be complicated with joint disc injury, joint capsule and joint ligament tissue relaxation, leading to the recurrence of joint dislocation. 1. Clinical manifestations: The patient is in a state of mouth opening, unable to open his mouth, drooling, eating and speaking difficulties, and shows extreme pain. The examination showed that the mandibular movement was limited and the front teeth were opened and closed reversely. The dislocated pleura is depressed in front and bulged under the zygomatic arch. X-ray shows that condyle is located in front of articular tubercle. Second, the treatment of acute joint dislocation should be reset in time, and the activity of mandible should be limited after reset. The most commonly used method is intraoral manual reduction. Before reduction, you can massage the bilateral masticatory muscles by hand to relax the muscles. Generally, anesthesia is not needed. When restoring, the patient sits on a dental chair or a low stool with his head resting on the back wall, and the occlusal surface of mandibular teeth is lower than the level of the doctor's elbow joint. The doctor stood in front of the patient, his hands and thumb were wrapped with gauze to avoid being bitten. Then put it into the patient's mouth, put it on the occlusal surface of the mandibular molar, and hold the lower edge of the mandible with the other four fingers. During reduction, the thumb presses the mandible downwards, and the other four points push the chin upwards, so that the condyle in front of the articular tubercle moves below the level of the articular tubercle, and then pushes it backwards and upwards, sending the condyle into the articular recess. If it is bilateral joint dislocation, one side can be reset first and then the other side. When the condyle is restored, the normal occlusal relationship has been restored. Bind and fix the mandible with elastic bandage or ordinary bandage for 2 ~ 3 weeks to limit the movement of mandible and avoid dislocation again. If it is not fixed or fixed for a short time after reduction and the torn tissue is not fully recovered, joint dislocation and temporomandibular joint disorder syndrome can occur again.