Difficulty in opening mouth is a common complication after radiotherapy for nasopharyngeal cancer and oral cancer, which is initially manifested as tightness and pain in temporomandibular joints when opening mouth, and if it continues to develop, the activities of temporomandibular joints will be restricted, the distance between open mouth and incisors will be narrowed day by day, and in serious cases, even the teeth will be tightened, which will cause difficulty in eating. There is no treatment for the difficulty of opening the mouth after radiotherapy, patients can only strengthen the exercise after radiotherapy to prevent the occurrence of this disease, the specific methods are as follows: 1, diligent exercise, that is, the oral cavity quickly open the mouth, and then closed, the amplitude of the range of their own tolerable. 2, diligent exercise, local self-massage, local self-massage. 2, diligent massage local self-massage, mainly in the temporomandibular joints to do gentle massage. 3, often smile and smile practice to exercise local muscles. 4, traditional Chinese medicine treatment of mouth opening difficulties due to the temporomandibular joint and its surrounding masticatory muscles, after radiation degenerative changes, muscle atrophy and fibrosis. It is characterized by temporomandibular joint movement disorder and temporomandibular joint pain when opening the mouth. There is no satisfactory solution for this. It has been reported that the Chinese medicine frankincense, myrrh, Tianqi, whole scorpion, Wei Ling Xian and other minced, added to the hot melted white wax and mixed well to make medicinal wax, every day will be soaked in hot water to the medicinal wax can be molded when the temporomandibular joints, and at the same time for the movement of opening and closing the mouth, and fingers rubbing the temporomandibular joints, the difficulty of opening the mouth has a certain effect of alleviation. This kind of radiotherapy injury is best to be able to prevent there is no particularly good treatment.