With the increasing awareness of people’s living standards and oral health care, more and more patients with malocclusion are going to dental hospitals for treatment by orthodontic specialists. Current orthodontic techniques can perfectly correct almost any complex malocclusion. For a variety of reasons about half of all patients require orthodontic extraction. Many patients and parents ask the question: Will orthodontically treated teeth loosen more easily in old age? Will they fall out earlier? The basic principle of orthodontic treatment for malocclusion is to apply force to the misaligned teeth or malformed jaws to produce histological alterations that will result in a new morphological and functional balance and normal development of the dental and jaw system, which is a biomechanical movement with complex biological content. After the teeth are moved by the force in the orthodontic process, the bone tissue around the roots is re-modeled, including two processes of proliferation and resorption, with bone destruction and new bone formation at the same time, both of which are skillfully coordinated and adjusted to achieve a new balance without damaging the teeth or the alveolar bone, so it is a physiological movement. There will be a certain degree of looseness of teeth during orthodontic treatment, but at the end of the treatment, with the cessation of bone reconstruction, the periodontal membrane, periodontal muscle tissue and alveolar bone will also reach a new balance, and the looseness of teeth will gradually recover until the teeth are completely stable in their new state. Therefore, there is no scientific basis to say that teeth will fall out early after orthodontic treatment, and there is no need for people to worry about this at all.