The jaw is protruding forward, may be caused by bad habits, may also be caused by uneven teeth alignment, may also be due to genetics, as follows: 1, bad habits caused by: common in infants and young children have bad habits of jaw forward, this time through the wearing of functional movable orthodontic appliances can correct the habit of jaw forward. 2, the teeth are not aligned: a part of the jaw protrusion is caused by uneven teeth alignment, the part The orthodontic correction of teeth alone can change the face shape. 3, genetic causes: there is also a part of the jaw protrusion is caused by genetics, that is, bony jaw protrusion, such as the parents jaw protrusion face is very obvious, the children’s chin to the front of the face will often be very large. In this case, orthodontic treatment alone is usually not ideal to change the face shape, and orthognathic surgery is needed when necessary.