Types of retainers Essix Hawley Permanent / Compared / Photos
Advantages and disadvantages of permanent retainers. 1) Fixed retainers work better in some applications. Research suggests that a fixed retainer is better able to hold a patient's lower front teeth (incisors) in position during the first months immediately following the completion of their active orthodontic treatment (Meade 2013, O'Rourke 2016).