When you open your mouth, there will be a thumping sound, which indicates that the temporomandibular joint disease, you need to go to the hospital to check the severity of the disease, and then do the hot compress physiotherapy or medication, surgical treatment. 1. Thumping when opening the mouth is common in temporomandibular joint dysfunction or structural disorder, thumping or bone friction sound occurs when opening and closing the mouth, and in serious cases, it can be painful when opening the mouth and pressing on it. 2. For functional disorders, wet and hot compresses, local physiotherapy or wearing bite plates can be applied according to the situation. In case of structural changes in the joints, hyaluronic acid can be injected into the joint cavity or arthroplasty can be performed under the operation of a doctor according to the severity. The popping sound is common in adults between 20 and 40 years of age and requires immediate treatment to prevent worsening of the condition and organic changes in the joints.