Bad oral habits are mainly for children, if oral habits are not corrected in a timely manner, it will cause the appearance of dental and maxillofacial deformities, children’s oral habits are mainly mouth breathing, finger biting, biting hard objects, lip biting, bad tongue habits and lateral chewing, etc., as follows: 1, open-mouth breathing is mostly due to the respiratory airway is not open, sinusitis, rhinitis, adenoid hypertrophy of the disease, will lead to respiratory The airway is not open, which leads to open-mouth breathing, mouth breathing habits will cause the upper dental arch narrowing, the upper teeth protrusion and jaw recession of the jaw facial deformity; 2, wrapped fingers and the habit of biting hard objects, will make some of the front teeth form a small local open and close, but also easy to cause ulcers of the oral mucosa; 3, habitual lip biting and lip licking will lead to the occurrence of labyrinthitis; 4, lateral chewing refers to long-term chewing food with only one side of the teeth, which will make the occlusal function, temporal and inferior temporal chewing. It will make the occlusal function, temporomandibular joint and chewing muscles change.