Protruding mouth in boys may be caused by protruding teeth, protruding jaws or receding jaws. 1. Protruding teeth: If the patient has protruding teeth due to heredity or bad habits, it may lead to protruding lips. It can be corrected by wearing braces, which can gradually bring the protruding teeth back to normal. 2. Jaw protrusion: Jaw protrusion may be caused by genetic factors, and there may also be developmental abnormalities, which will make the lips wrapped around the jawbone become protruding, if it is caused by protruding jawbone protruding lips, it can be improved by the way of intra-oral orthodontics orthognathic combined treatment. Boys with protruding mouths should go to the hospital in time, determine the cause under the doctor’s diagnosis, and choose the appropriate way to improve the treatment.