Temporomandibular joint disorder is one of the most common diseases of the oral and maxillofacial region. It occurs in young and middle-aged people, and up to 80% of college students have related symptoms. The cause of the disease is not yet completely clear. It may be related to the following factors: 1, psychosocial factors: mental tension, irritability, anxiety, fatigue, insomnia, etc.; 2, occlusal factors: tooth misalignment, joint interference, etc. (such as ectopic eruption of wisdom teeth); 3, excessive load on the joint (such as night grinding, often eating hard food, clenching teeth during the day, lateral chewing, etc.); 4, other factors (such as cold stimulation of the joint area, long-term poor posture), etc. The clinical manifestations are: abnormal movement of the jaw (e.g. skewed opening), pain in the joint area (mainly around the ear, which needs to be distinguished from otogenic diseases), popping and murmuring (karate-karate-karate when opening the mouth). Treatment: This disease is self-limiting! Most young patients improve on their own or heal on their own! In the early stages of the disease, care should be taken to protect the joint by avoiding chewing hard objects, opening the mouth widely, and avoiding bad habits. Observe for 1 week. If the symptoms continue to worsen, it is recommended to consult a doctor for a clear diagnosis and, if necessary, to take oral medication or use a personalized and symptomatic treatment plan.