A protruding mouth and retracted jaw may be caused by anterior protrusion of teeth, anterior protrusion of the maxilla, or retraction of the mandible, which can be improved by orthodontic treatment, orthognathic treatment, and so on. 1. Anterior protrusion of teeth: If the protrusion of teeth is the cause of mouth convexity and jaw retraction, it can be improved by orthodontic treatment. It is the use of orthodontic appliances inside or outside the mouth to apply biological forces on the teeth, alveolar bone and jawbone to make them move, so as to improve the protruding mouth and retracting jaw. 2. Maxillary protrusion and mandibular retrusion: The protrusion of the maxilla and mandibular retrusion can also be caused by the protrusion of the maxilla and mandibular retrusion, which can be improved by orthognathic treatment. This is a surgical procedure that amputates the maxilla and mandible and moves the maxilla and mandible to the desired position, thus improving the condition of a protruding mouth and receding chin. There are many reasons for the retrusion of the mouth and jaw, so it is recommended to go to a regular hospital for examination to clarify the cause and choose the appropriate improvement method under the doctor’s guidance. During the treatment period, it is recommended to eat less hard food, so as not to cause the burden of the oral cavity, affecting the treatment effect. At the same time, we should keep the mouth clean, rinse and brush teeth diligently, which can reduce the appearance of gingivitis and other complications.