Children occasionally crooked mouth may be due to children like to imitate caused by, may also be some disease symptoms such as facial nerve paralysis, brain tumors, etc., need to go to the hospital in time to find out the cause of the disease. 1. Bad habits: Because children are in the rapid growth and development period, curiosity is more vigorous, most children like to imitate the adults around them. Children will imitate the crooked mouth of their family members, close friends or certain characters in videos, thus they will have the phenomenon of crooked mouth occasionally. 2. Facial nerve palsy: Facial nerve palsy refers to the damage to the facial nerve, resulting in facial muscle activity disorders, which can be divided into central and peripheral facial nerve palsy. 3. Brain tumor: Due to the different locations, sizes and degrees of invasion of brain tumors, the corresponding clinical symptoms are also different. If the brain tumor is adjacent to the optic nerve, it may lead to visual field defect; if it is adjacent to the functional area, it may affect the facial nerve and lead to crooked mouth. There may be other reasons for children to have crooked mouth occasionally. It is recommended to go to the hospital in time, complete the examination to clarify the cause of the disease, and then give targeted treatment or therapy under the guidance of the doctor.