The development of temporomandibular joint anterior displacement is a progressive disorder, and the development of the disease mainly includes the following three processes: the phase of reversible joint anterior displacement, the main clinical characteristics of this phase are, when the jaw makes opening and closing movements, there is a round-trip joint popping sound in the affected joint area; the phase of reversible joint anterior displacement with locking in the jaw movement, that is, the phase of locking, the duration of this phase varies, the main clinical manifestations of this phase are When the patient opens the mouth by himself, the affected temporomandibular joint has a locking sensation, after several adjustments of the lateral jaw movement, the affected joint has a single popping sound, then the patient can open the mouth, the affected joint usually has no spontaneous pain, most patients have a locking sensation especially in the morning when they get up, and the patient mostly has an abnormal opening type; irreducible anterior displacement of the joint disc stage, with the further development of the locking stage, if not treated in time, that is, irreducible The main manifestation of anterior displacement of the joint disc is painful opening of the mouth and restriction of opening of the mouth. Hyaluronic acid, a polymeric polysaccharide, is widely found in the intercellular matrix of connective tissues and is actually present in the form of sodium salts. Since the discovery of hyaluronic acid by Meyer in 1934, exogenous sodium hyaluronate has been used as a biomaterial in the fields of ophthalmology and surgery. Studies have confirmed that hyaluronic acid has a lubricating effect on joints in the joint cavity, plays an important protective role on cartilage surfaces and soft tissue surfaces, and also stimulates the synthesis of endogenous hyaluronic acid. Hyaluronic acid has a large negative charge and has a repulsive effect on negatively charged fibroblasts, plays an important role in the extracellular regulation of inflammatory cell exudation, inhibits the exudation of lymphocytes, macrophages and granulocytes, has an anti-inflammatory effect, and can reduce the formation of postoperative scars without affecting wound healing. Hyaluronic acid can also prevent joint stiffness, tendon adhesions and abdominal adhesions. In view of the pharmacological properties of sodium hyaluronate, TMJ clinics have applied this drug in the treatment of temporomandibular joint disorders and anterior displacement of the joint disc. The application of sodium hyaluronate improves the internal environment of the joint cavity, changes the pressure in the joint cavity, and increases the lubrication of the joint fluid, thus increasing the lubrication between the joint disc and the joint fossa. The alteration of the intra-articular environment and the increase in joint lubrication are the most important factors leading to significant improvement in the symptoms of joint locking. A large number of clinical patient follow-ups have confirmed that supra-articular cavity injection of sodium hyaluronate, which is simple to perform, minimally invasive, and repeatable, is an effective treatment for TMJ disc displacement.