Lower lip ectropion can be caused by soft tissue morphology abnormality or oral malocclusion, according to the severity of the situation, need to take soft tissue repair or orthodontic orthognathic treatment. 1. Abnormal soft tissue morphology. Normal lower lip and upper lip are coordinated and don’t turn out. Lower lip turning out may be caused by congenital deformity of soft tissues, which requires plastic surgery to restore the normal lip shape, or it may be caused by allergy-causing drugs, which requires stopping the contact with allergens and taking anti-allergy drugs such as loratadine immediately. 2. Oral malocclusion. Dental malocclusion or abnormal development of the jawbone can cause lower lip protrusion, dental malocclusion needs orthodontic treatment to align the teeth, jawbone overdevelopment caused by the need for orthognathic surgery to repair the jawbone. Lower lip protrusion, it is recommended to go to the hospital to check the specific situation after targeted treatment.