The causes of temporomandibular disorder have not been completely elucidated, and most scholars have proposed some factors related to the pathogenesis of this disease based on experimental and clinical studies. Generally speaking, its etiology is related to the following factors: psychosomatic factors, dental disorders and malocclusion, continuous overload of teeth, lateral chewing, anatomical factors, endocrine factors and some bad habits, etc. The most common malocclusion is deep overmandibularity and deep coverage, which means that the upper teeth cover the lower teeth too deeply and too far (the distance between the upper and lower teeth is too large) and too far (the distance between the front and back is too large), and the head of the lower jaw (condyle) is easily in a posterior receding position, and the relative joint disc is easily displaced in an anterior position. Mental factors are common triggers of the disease. Nowadays, society, people are under more and more pressure. Anxiety, depression and other bad emotions will make some people transfer the pressure to the masticatory muscles, causing excessive contraction and hyperactivity of the masticatory muscles, involuntary clenching of teeth and night grinding, which will cause excessive pressure on the joints and lead to chronic joint injury; in addition, the excessive force of the masticatory muscles will excessively pull the articular disc forward and eventually lead to the anterior displacement of the articular disc. In some patients with reversible anterior displacement of the disc, excessive mental stress and tension will aggravate the condition and eventually lead to the occurrence of irreversible anterior displacement of the disc. Preferring to chew harder or tougher foods, chewing on the side, etc., can put more pressure on the joint, which can cause chronic joint damage. Estrogen levels may be associated with female patients, with a relative prevalence of women with the condition and a higher rate of female visits. Bilateral asymmetric development of the condyles due to anatomical factors, or hypertrophy of the condyles, or weakness of the joint capsule articular ligaments can also lead to TMJ disorder. In conclusion, people with the above related etiologies are more likely to develop the disease, but not people with such etiologies will necessarily develop the disease; even after the disease, it is important to maintain a cheerful mood and optimistic attitude, and even some patients may not seek medical consultation, thinking that it is not a disease (indeed, some patients with reversible anterior disc displacement can remain in this state for a long time without further development in clinical practice); while some patients are optimistic when they seek medical consultation and actively cooperate with their doctors and often obtain better treatment results.