Retention devices are used to prevent recurrence that may follow orthodontic treatment. For this purpose, the devices hold the teeth in the desired position and ensure a stable relationship between the two maxillae. Also dentists must make sure to choose the proper retention device for the treatment. Finally, a recurrence could occur between the moment of the impression and that of the manufacture of the device. That is why it is better to leave the orthodontic cases and the rings with the molars to remove them only at the time of the setting in mouth. Obviously, our technicians will grind them on the models before making the device.