At the age of 30, of course, teeth can still be corrected. In terms of current orthodontic theory, orthodontics can be performed on adults as long as they are in healthy periodontal condition and have no systemic diseases. In Europe and the United States, and even in China, many people in their 40s and even 50s are currently undergoing orthodontic treatment in the pursuit of beauty, so technically there is no problem at all. The older you are, the greater the risk of orthodontics, which may cause various problems in the periodontium. Therefore, you should consult with a professional orthodontist before having orthodontics, and have a full body checkup and laboratory tests to see if your body can tolerate orthodontics before deciding whether to have orthodontics.