The performance of pain in the left cheek when the mouth is wide open is commonly associated with temporomandibular joint disorders, a group of diseases in which the temporomandibular joint and masticatory muscles appear to be functionally, structurally and organically altered due to multiple factors such as mental factors, microtrauma, infection, immunity, etc. In addition, it needs to be differentiated from mumps, trigeminal neuralgia and other diseases: 1. Temporomandibular joint disorders: can be divided into masticatory muscle disorders diseases, inflammatory diseases, structural disorders diseases and degenerative joint diseases, which can be manifested as pain in the temporal and occlusal muscles during jaw movement, sometimes radiating to the periphery, clinically based on conservative treatment, patients try to reduce jaw activity, and can relieve pain through heat, acupuncture, taking non-steroidal anti-inflammatory drugs or closed treatment; 2, mumps: infectious mumps is the most common, the causative agent is mostly bacteria or viruses, the parotid gland is located on both cheeks near the earlobe area. When inflammation exists, the mouth activity can pull the local tissue causing cheek pain. Bacterial infections can be treated with antibiotics, while viral infections are treated symptomatically, drinking more water, keeping the mouth clean, and using antiviral drugs as appropriate. 3. Secondary trigeminal neuralgia needs to be treated for the cause. Primary trigeminal neuralgia can be treated by medication, such as carbamazepine and phenytoin sodium, etc. Radiofrequency temperature-controlled thermocoagulation of the semilunar ganglion as well as acupuncture therapy and closure therapy also have certain efficacy.