Jaw joint pain is one of the clinical manifestations of temporomandibular joint dysfunction syndrome, and the temporomandibular joint is the only joint of the face, and its structure and movement are among the most complex joints in the human body. The movements of chewing, speech, swallowing and expression in our daily life all depend on the normal participation of TMJ. TMJ disorder is a common disease in the oral cavity, with a high prevalence in the population, and is one of the most common diseases of the oral and maxillofacial region, besides dental caries, periodontal disease and malocclusion. So what is the pathological cause of jaw joint pain? Let’s introduce it to you below. Many aspects of the etiology of temporomandibular disorders are still unclear. In contrast to dental/incisive causes, evidence for the existence of a biopsychosocial and multifactorial background has been identified, suggesting a complex interplay between biological (e.g., hormonal) mechanisms, psychological states and characteristics, environmental conditions, and trauma, both large and small. In masticatory pain, muscle overload (abnormal function, tooth grinding), (micro)trauma or local inflammation can release neurotransmitters that sensitize the peripheral and central nervous system. In combination with altered pain modulation mechanisms (also influenced by estrogen), this sensitization can lead to a local or more widespread spread of muscle pain. Jaw joint pain can arise from trauma to the TMJ or from internal or external overload (e.g. in teeth grinding) that may exceed the adaptive loading capacity of the joint tissues. In addition, the adaptive loading capacity of the TMJ can be diminished by endogenous factors, such as decreased blood supply and nutrition. Genetics and gender also influence the pathophysiology of osteoarthritis. The production of free radicals, pro-inflammatory and pain receptor neuropeptides, enzymes, bone morphogenetic proteins, and growth factors can lead to inflammation, pain, and progressive tissue changes.