In humans, there is a small joint in front of the ear called the temporomandibular joint (TMJ), which connects the skull to the mandible. It is this joint that allows the jaw to move and function, and it is the joint that moves most frequently throughout the body. What is TMJ disorder? Temporomandibular joint disorder (TMD) is one of the most common diseases of the oral and maxillofacial region and is one of the four diseases with the highest clinical incidence in dentistry (caries, periodontal disease, TMJ disorder, and malocclusion). Temporomandibular joint disorder is common in young adults, and it is more common in women, with the highest prevalence in 20-30 years old, and the incidence rate is 28%~88%. TMJ disorders are classified as masticatory muscle disorders, structural disorders, inflammatory diseases and osteoarthrosis. The main features are abnormal jaw movement, pain in the joint area, popping and murmur, etc. Some patients are accompanied by headache, ear symptoms, and even neck and shoulder pain. Through the clinical treatment of 10,000 cases of TMJ disorders, a hospital professor has proposed the treatment plan of “sequential gradient treatment”. ①3M treatment: For patients with headache symptoms at the early stage of clinical development, Modality (physical therapy), Manual (manual therapy) and Movement (exercise therapy) are used. Physical therapy includes reliance on instruments. For TMD, the common physical therapies are wet heat, ultrasound, short wave, low frequency electrotherapy, etc. The purpose of physical therapy is anti-inflammatory and analgesic. Manual therapy is a variety of stretching and loosening techniques mobilization, the main role is to increase the mobility of TMJ, that is, to increase its mobility in all directions, including openness, anterior extension, and left and right lateral deviation. Movement therapy refers to retraining the neuromuscular control by designing movements under professional guidance in an attempt to restore the normal movement of TMJ. (2) Occlusal plate treatment: teeth, joints, muscles and nerves are closely linked together, and when the four do not act in harmony, TMJ disorder may result. There are dozens of types of occlusal plates, but only five or six types are commonly used in the treatment of TMJ disorders, such as the full bite stabilization plate, mandibular anterior extension guide plate, full anatomical bite plate, pivot bite plate and so on. The main purpose is to adjust the occlusal relationship, the position of the muscles, the condyles and the articular disc, so as to gradually establish a stable “condylar disc” relationship. This stabilization will bring about new stress changes, thus treating TMJ disorders. (3) Injection therapy: also called “elasticity supplementation therapy”, both clinical and basic research have confirmed that patients with TMJ disorders have less “joint fluid” in the joint cavity. Therefore, we try to inject the components of joint fluid (medical sodium hyaluronate gel or medical chitosan) into the joint cavity to play the role of “lubrication, repair, antibacterial and balance”, thus reducing friction, inflammatory factor leakage and changing the movement of joint disc to treat TMJ disorders. One is that lavage can loosen small adhesions in the joint cavity, change the intra-articular environment, remove inflammatory substances and pain factors, restore normal intra-articular pressure, and reduce inflammatory fluid leakage. The second is to eliminate the suction cup effect, which refers to abnormal mandibular movements such as night grinding and clenching of teeth that make the joint overloaded and generate excessive negative pressure in the supra-articular cavity. When the load is removed, the middle part of the articular disc and the articular tuberosity are separated, while the circumference of the articular disc is still adsorbed on the surface of the tuberosity and the articular fossa, and the repositioning activity of the articular disc is restricted. Supratrochlear irrigation of the temporomandibular joint is mainly indicated for patients with structural changes in the temporomandibular joint, such as early stage of reducible anterior displacement of the disc with strangulation and irreducible anterior displacement of the disc. For patients presenting with acute pain and difficulty in opening the mouth, the shorter the duration of the disease, the better the treatment effect; the younger the patient, the better the treatment effect. In addition, there is also a clear treatment effect for TMJ synovitis and osteoarthritis. ⑤ Minimally invasive temporomandibular arthroscopy: Temporomandibular arthroscopy has been used for the treatment of temporomandibular joint diseases for more than 20 years, but for various reasons, it is still far from being promoted in China. This is related to the changing philosophy of TMJ disease treatment, and the uncertainty of the efficacy of arthroscopic treatment. TMJ arthroscopy is a less invasive treatment, which allows doctors to diagnose and treat various joint diseases by cutting two “peanut nut” sized or smaller holes (5-10 mm) in the skin and inserting cameras and surgical instruments into the TMJ under monitor surveillance. Through arthroscopy, surgical operations such as joint cavity lavage, anterior joint band adhesion release, joint disc repositioning, and joint capsule tightening can be performed under direct vision. Compared with traditional open surgery, arthroscopic minimally invasive surgery has small incision, less damage to surrounding tissues, shorter operation time, less bleeding, less concealed scar, less complications and can be performed under local anesthesia, which is easier for patients to accept. (6) Open surgery: Surgery is not the main treatment for TMD, and this concept has been accepted by most international TMD specialists. At present, the indications for surgery are limited only to patients who have had poor results from serial conservative treatment, patients with significant organic damage and severe dysfunction of the temporomandibular joint, patients who have developed the disease and are unable to live a normal working life, and patients who urgently request surgery and strongly request surgery even though they are told that it may not be effective. The cost and risk of surgical treatment is always greater for patients than for those treated conservatively. Any treatment has a cost to the patient in terms of time, money, pain and stress, side effects, complications, sequelae, tissue or organ damage and loss, and accidents. As a result, only about 10% of our tens of thousands of TMD patients actually undergo open surgery. No matter which treatment modality the attending physician chooses, he or she always wants his or her patients to improve, get better, be cured or even cured. Therefore, a highly skilled surgeon must choose to make the patient’s payment as minimal as possible and the treatment effect the patient receives as maximum as possible. The greater the ratio, the better the choice. The principle of maximizing efficacy is the principle that any “good doctor” should consider, and it is also the golden rule of TMJ disorder treatment selection.