Adult's face is mainly composed of palatine bone and mandible, plus facial muscles; Maxillary arch expansion only affects dental arch, but has little effect on adult facial shape; If the child is at the peak of development, arch expansion can expand the width of maxilla and mandible, which may affect the face shape; It is suggested that after comprehensive examination, we should discuss with the attending physician whether to correct by expanding the arch, and at the same time, expanding the arch is easy to recur. from/question/3805 16573 . html