Contemporary orthodontic treatment should be thought of as a two-step process: active treatment and retention. Active treatment involves modification of tooth position with fixed (braces) or removable thermoplastic appliances. Retention refers to the period of supervised maintenance of the teeth in their corrected positions with retainers after active appliances are removed. Studies have demonstrated that wearing a removable retainer full-time after braces removal is essential for maintaining tooth position. Patients who do not comply with wearing their retainers during this initial period of orthodontic retention will experience some form of relapse.

Orthodontic retainers are absolutely necessary for three principal reasons: 1) the gingival and periodontal tissues surrounding the teeth are affected by orthodontic tooth movement and require time for reorganization when the active appliances are removed; 2) the teeth may be in an inherently unstable position after active treatment, so that soft tissue pressures from the lips and cheeks constantly produce a relapse tendency; and 3) changes produced by facial growth may alter the orthodontic treatment result in growing patients. Reorganization of the periodontal ligament (PDL) occurs over a 3 to 4 month period after active appliance removal. Reorganization of the collagenous and elastic fibers in the gingiva occurs more slowly than that of the PDL. The collagenous fiber networks within the gingiva complete their reorganization by 4 to 6 months after active appliance removal. The elastic supracrestal fibers remodel very slowly and can still exert forces capable of tooth movement 1 year after active appliance removal.

What can I do to preserve my smile?

There is general agreement among orthodontists that patients must have some type of retention following active treatment in order to maintain the treatment result in the short and long term. Although the data in scientific journals is limited, some authors have suggested that retention appliances be placed shortly after the active appliances are removed, worn full-time except during meals for the first 3 to 4 months and then worn part-time until one to two years after active appliance removal. In practice, most orthodontists develop their own patient-specific retention protocols that are based on what they have seen clinically after years of practice. So, it is essential that you understand your individualized retainer prescription and that you adhere to the schedule recommended by your orthodontist.