The main causes of buck teeth in children are genetic factors, bad habits, oral and maxillofacial diseases. Buck teeth is a common dental and maxillofacial deformity. The factors that cause buck teeth are mainly genetic, but also can be caused by bad habits such as open mouth breathing, finger sucking, biting the lower lip, etc. It may also be related to diseases such as overgrowth of the teeth and jaws, abnormalities of the dentition, missing milk teeth, and supernumerary teeth. Buck teeth are categorized into dental buck teeth and bony buck teeth. Buck teeth in children may appear as open lips, lips can not be closed in the natural state, or the upper front teeth are often tilted to the side of the lips, the middle of the face is obviously protruding and the lower part of the nose shows a convex surface and other manifestations. Children with dental buck teeth can be improved by wearing orthodontic appliances, while bony buck teeth require surgical methods, such as surgical osteotomy, grinding teeth with restorations and so on. Parents should pay attention to their children’s buck teeth and bring them to the hospital in time, and the doctor should make a suitable and effective treatment plan, so as not to affect the aesthetics. In addition, children should correct bad habits, such as pencil biting, lip biting, finger sucking, unilateral chewing and so on.