There are many reasons why your mouth is a little crooked. Congenital dysplasia refers to the abnormal development of the mouth or corners of the mouth before or after birth, resulting in a bit crooked mouth. This situation will not have much impact on health, but if it is seriously skewed, it will affect the beauty and chewing function and need plastic surgery. Facial paralysis is a common nervous system disease. Because the facial nerve is damaged, it leads to facial muscle movement disorder, which leads to a slightly crooked mouth. There are many reasons for facial paralysis, such as infection, stroke and craniocerebral injury. The treatment of facial paralysis includes acupuncture, physical therapy and other comprehensive treatments to promote the recovery of facial nerve and relieve the symptoms of mouth deviation. A little crooked mouth is also caused by some diseases or accidental injuries. For example, when suffering from oral cancer, lip cancer and other diseases, tumor invasion or surgery will lead to mouth skew. When encountering accidents such as car accidents and falls, it will cause oral soft tissue or bone damage, resulting in a slightly crooked mouth.