Types of Retainers Retainers are classified into two types as Removable retainers and Permanent retainers. Each type has its advantages and disadvantages. The Orthodontists suggest a suitable one depending on the kind of bite problem you had. The straightened teeth can move back to their places after removing the braces due to the absence of force applied by the orthodontic braces over the teeth. The bone around the aligned teeth has to be rebuilt to hold the teeth in their aligned position. Usually, this process takes an average of 3 to 6 months. Until then, you should protect the teeth from naturally generated forces to keep the teeth from moving. An orthodontic retainer is an appliance that can hold the teeth in their place after wrapping the orthodontic treatment. A detailed not on the different types of retainers are explained here. 1) Removable Retainers As the name suggests, the removable retainers can be easily taken out from the mouth when you want. Fixing this retainer does not need support from dentists. This retainer is fabricated with a metal wire and plastic. If you want the appliance in an exact match of the roof of your mouth, then the plastic will be replaced with acrylic material.