An orthodontic retainer is a custom-made appliance designed to maintain the new, straight alignment of your teeth after active treatment with braces or aligners is complete. This device acts as a necessary safeguard for the results of your treatment. Orthodontic professionals strongly discourage wearing only the top or only the bottom retainer. Wearing only one retainer can lead to unintended shifting and complications that may be worse than wearing no retainer at all.
Why Retainers Are Necessary After Treatment
Retainers are required because teeth are not set rigidly in the jawbone; instead, they are held in place by a complex network of fibers known as the periodontal ligaments. During orthodontic treatment, these ligaments are stretched, compressed, and reorganized as the teeth move into new positions. These fibers have a “memory” and a natural tendency to pull the teeth back toward their original misalignment, a process called orthodontic relapse.
It takes significant time for the surrounding bone and periodontal ligaments to fully stabilize and adjust to the new alignment. The first three to six months following the removal of braces are the most sensitive period for relapse to occur. Furthermore, the jaw and bite continue to settle and change throughout life due to natural growth, aging, and pressures from the tongue and lips. Retainers hold the teeth firmly in place during this extended stabilization period, ensuring the long-term stability of the corrected bite.
The Consequences of Retaining Only One Arch
Wearing a retainer on only one arch introduces a significant imbalance that can compromise the entire bite. The retained arch remains stable, but the non-retained arch, such as the bottom teeth, will inevitably begin to shift. The lower teeth, which are prone to age-related crowding, may quickly revert toward their former positions.
This differential movement creates a mismatch, leading to a condition called malocclusion, or a bad bite. When you bite down, the teeth will no longer meet correctly, potentially causing functional issues. The stable, retained arch can exert pressure against the shifting teeth, resulting in uneven wear patterns or greater misalignment. Correcting this new bite misalignment often requires a second round of orthodontic treatment, negating the results of the initial treatment.
Troubleshooting Common Retainer Issues
Compliance often falters when issues arise with the retainer, but most problems require immediate attention from your orthodontist. If a removable retainer feels loose or does not snap fully into place, it indicates that your teeth have already shifted slightly from inconsistent wear. Never try to force a retainer that does not fit, as this can damage the appliance or your teeth; instead, contact your orthodontist for an assessment or adjustment.
If a retainer is lost or broken, stop wearing the damaged appliance immediately and schedule a replacement appointment, as delays allow significant tooth movement. Keep removable retainers clean using a soft-bristled brush and mild soap, avoiding abrasive toothpaste or hot water, which can warp the material. Always store the retainer in its protective case when it is not in your mouth to prevent damage or loss.