Jaw is hit and open mouth pain may be related to jaw joint injury, local soft tissue injury, temporomandibular joint dislocation and other factors, you can medication to relieve pain, with life care, such as dislocation of the jaw needs to be reset. 1. Jaw joint injury: the jaw is hit by the pain of opening the mouth may be jaw joint injury, at this time you can use acetaminophen, aspirin and other drugs to reduce inflammation, pain. Usually less talking, less chewing, reduce jaw activities. 2. Local soft tissue damage: the chin was hit by the local soft tissue damage, there will be symptoms of pain when opening the mouth, you can apply cold compresses to relieve pain, pain is obvious when oral ibuprofen and other drugs to relieve the pain, daily diet, eat more fluids, semi-fluids and other foods that do not need to be chewed. 3. Temporomandibular joint dislocation: when the jaw is hit, resulting in temporomandibular joint dislocation, there will be obvious pain when you open your mouth. For temporomandibular joint dislocation, it is necessary to reset in time, and after resetting, it is necessary to limit the movement of the jaw. When the jaw is hit and it hurts to open the mouth, the patient can first go to the regular hospital, and the doctor will determine the cause of the disease and then targeted treatment and medication.