Overview: Temporomandibular joint disorder syndrome is the most common disorder of the oral and maxillofacial region, and the pathogenesis is not fully understood. The main clinical manifestations of this disorder are pain in the joint area, joint popping during movement, and jaw movement disorder. Most of them are joint dysfunction and have good prognosis; however, organic changes may occur in very few cases. 1.Psychological factors Psychological factors play a very important role in the occurrence and aggravation of TMJ disorder syndrome. 2, trauma factors Many patients have a history of local trauma. For example, they have suffered acute trauma such as external impact, sudden biting of hard objects, excessive opening of mouth (such as yawning); and frequent chewing of hard food, grinding of teeth at night and unilateral chewing habits. These factors may cause joint contusion or strain, masticatory muscle group dysfunction. 3, occlusal factors Occlusal disorders can also lead to the occurrence or aggravation of temporomandibular joint disorder syndrome. Such as occlusal interference, excessive tooth wear, excessive missing molar teeth, bad restorations, low intermaxillary distance, etc. Disturbance of the occlusal relationship can disrupt the balance of function between the internal structures of the joint and contribute to the occurrence of this syndrome. 4. Systemic and other factors Systemic diseases, such as rheumatoid arthritis, can also cause TMJ disorders. In addition, some medical factors, such as radiation therapy for nasopharyngeal cancer, can lead to structural and functional changes in the masticatory muscles, which can also cause TMJ disorder syndrome. Clinical manifestations: The main clinical manifestations of TMJ disorder include localized joint soreness or pain, joint popping and jaw movement disorders. The pain may be in the joint area or around the joint; it may be accompanied by pressure pain of varying severity. The soreness or pain of the joint is especially obvious when chewing and opening the mouth. The popping occurs during mouth opening activities. The ringing can occur at different stages of jaw movement and can be a crisp single ringing sound or a cracking continuous ringing sound. The common motor obstruction is restricted mouth opening, jaw deviation during mouth opening, and restricted left and right side movement of the jaw. In addition, it can be accompanied by temporal pain, dizziness, tinnitus and other symptoms. Treatment: 1. First of all, the influence of mental factors should be removed, and if necessary, the assistance of a psychiatrist is needed to develop a treatment plan. 2.Correct the occlusal relationship. 3.Correct bad habits, such as over-open mouth, unilateral chewing, etc. 4.Physiotherapy to relieve local symptoms. 5.Treat with medications or perform closure therapy if necessary.