Many people choose to have their teeth straightened because they can become aesthetically pleasing. The best age for orthodontics is before adulthood, orthodontics is less difficult and less time consuming, and there will be no rebound. 30 years old orthodontics is also possible to correct teeth, but it will bring some harm. The structure of the alveolar bone is not yet mature and can be easily changed when orthodontic treatment is performed by a minor, while the structure of the alveolar bone is already stable and cannot be easily changed at the age of thirty, which may cause damage to the roots of the teeth. Thirty years old orthodontic teeth is likely to have loose teeth, this is because the teeth have formed the inherent physiological curvature, this curvature is to relieve the pressure in eating and chewing, to prevent tooth injury, has formed the curvature, in the orthodontic process will change, it is easy to cause tooth damage, in addition in the reconstruction process, older, the reconstruction ability is poor, it is easy to have loose teeth. Thirty years old orthodontic teeth will also affect the height of the alveolar bone, because when wearing orthodontic appliances will be prone to oral cleaning is not enough, gum inflammation, affecting the alveolar bone. There are many risks associated with orthodontic treatment at the age of thirty, and adequate examination should be done before orthodontic treatment. However, it does not mean that orthodontics cannot be performed at the age of thirty.