Many people who want to have orthodontic treatment have some doubts: Is it true that teeth can move? How do teeth move when they are growing in the bone? Will it hurt the nerves? Here is a clarification: teeth can be moved and have their own unique mechanism. The teeth grow in the alveolar bone and there is a membrane structure called periodontal membrane between the teeth and the bone. When the teeth are moved by the force, the periodontal membrane changes and the alveolar bone is deformed, thus driving the teeth to move. 1, the source of orthodontic force Orthodontic force generally has two sources, one is the return force of the archwires, orthodontists in the patient’s teeth bonded brackets, followed by the placement of different archwires in the groove, using its deformation to obtain orthodontic force; the other, relying on the rubber band or rubber chain hanging in the brackets generated. Some small patients also have to carry out functional orthodontic treatment, in this case, the orthodontic force will mainly rely on the contraction force of the perioral muscles. 2, orthodontic force on the periodontal membrane and the mechanism of action of the alveolar bone During the orthodontic process, the periodontal membrane, as the first effect tissue on the teeth, will be compressed and stretched by the orthodontic force. Subsequently, the periodontal tissue produces a signal molecule that is involved in the tooth remodeling process. After the tooth is stressed, the bone at one end of the alveolar bone will undergo resorption due to compression and new bone will be formed at the other end in stretching. In the process of this change, the tooth will also move accordingly. 3.Will it hurt the nerve? The thickness of periodontal membrane is about 0.25mm, which is used to cushion and absorb the external force. In this way, when the tooth is moved by the force, it will not directly contact with the bone and cause trauma. The periodontal membrane is rich in nerves and blood vessels, which cause pain and swelling when they are compressed, but the compression of the nerves and blood vessels will gradually disappear as the alveolar bone completes its osteotomy and osteogenesis and the teeth gradually move towards the target position. The entire orthodontic process is a repetition of this change. The amount of force and timing of the treatment should be precise so that the nerves are not injured, which is a great test of the doctor’s skill. In conclusion, the movement of teeth in orthodontics is a series of complex physiological changes that occur after the periodontal membrane, alveolar bone, dental bone and other periodontal tissues are subjected to external forces, with its scientific movement mechanism, but also in line with the physiological basis, there is no exaggerated risk as legendary, as long as the regular institutions and professional experts under the guidance of the safe and effective.