Orthodontic treatment needs to be maintained after orthodontic treatment is completed. Fixed retention is popular among doctors and patients for its convenience and effectiveness. But most clinicians for how to choose to keep the arch wire size or method there are misunderstandings, the orthodontic guru from Oslo, Norway in the American Journal of Orthodontics (AJODO) centennial special article column (CENTENNIALSPECIAL ARTICLE) for us to talk about his application of fixed retainers experience, with a view to clinical selection of fixed retainers to play a useful help. 1. In the mid-1970s, the idea of fixed retention germinated. 2. In 1975, the author started to use composite resin to fix the adjacent points of teeth together, but it usually broke and failed after a few weeks. After many failures, the authors came up with the idea of adding stainless steel wires to the composite resin as a fixed retention, similar to adding steel reinforcement to cement. 4. The next clinical study found that 0.0215-inch 5-strand twisted wire was the most suitable for use as a fixed retention archwire. Stainless steel garden wire, square wire and glass fiber reinforced resin are not suitable for retention. 5. It is recommended to use a short arch for retention. 8 teeth in a row are more likely to fail. In the upper jaw 2 to 2 retention is recommended, and the lower jaw can be 3 to 3 retention. In order to prevent the reappearance of the extraction gap, a labial 2-tooth retention can be considered. 6, the authors commonly used retention methods are as follows: maxillary 2-2 retention: labial retention: 7, the choice of retainer to consider the patient’s initial misalignment characteristics, diagnostic records, oral habits, cooperativeness, growth pattern and age.