It usually takes 5~7 days to recover from inability to open the mouth after tooth extraction, if the symptoms are serious, it may take longer, hot compresses and physical therapy can help to restore the normal degree of opening, as follows. The inability to open the mouth after tooth extraction may be caused by accidental injury to the nerve during the extraction process, or traumatic inflammatory provocation, resulting in reflexive muscle spasm. It can be promoted by local cold compresses within 24 hours after the operation, and hot compresses, physiotherapy or hot gargles for local muscles after 48 hours to restore the normal degree of opening. There may be other reasons why you can’t open your mouth after tooth extraction, if accompanied by other discomforts or maintained for a long time, it is recommended that you go to the hospital in time to receive regular treatment as soon as possible after clarifying the cause of the disease.