Retention plays an important part during orthodontic treatment. Orthodontic treatment can be divided into 2 phases: an active phase in which treatment is carried out with orthodontic appliances and a second, passive phase with retention, with which an attempt is made to prevent a return to the original or another position. In practice, fixed retainers with a retention wire are usually chosen because of the many advantages of such wires. Even though fixed retention is now the gold standard in orthodontic follow-up, it does fail fairly often. In particular, because the procedures for manufacturing and placing are technically sensitive. A number of studies report that on average 34.9% (range of 10.3-47%) of the bonded retention wires come loose after an average of 2 years. A number of factors play a part in this. Based on the literature, it is possible to make some practical recommendations on the lifespan of a retainer.