A long-term stable retention is one of the most important links of orthodontic treatment. Most methods are flexible, and doctors should appropriate methods according to the type of malocclusion. Hawley retainer, vacuum-formed retainer, lingual fixed retainer, and its modified version are commonly used in clinics. This paper summarizes four aspects that maintain the effect, influence on periodontal health, compliance, and comfort level of the retainers to provide reference for clinical reasonable selection.
