The Mystery of Orthodontic Retainers

How many times have you heard about someone who had braces years ago, and now their teeth are right back where they started. The story usually includes something about not wearing a retainer for very long for various reasons … lost it, dog ate it or I was told that I didn’t need to wear it anymore. In this article, I will attempt to set the story straight on retainer wear, why it’s important and how long you need to wear your retainers.

First of all, allow me to briefly describe what happens when teeth move from point A to point B. Essentially, teeth have roots that are surrounded by bone, but there is a little space between the roots and surrounding bone that has little elastic-type fibres. That’s why you can wiggle any tooth in your mouth and it moves a little bit. When pressure is applied to a tooth, some fibres get stretched and others compressed, the root pushes against the bone and there is remodelling of the fibres and bone. This remodelling is how a tooth moves. Once a tooth is in its new position, it generally takes many months for the bone to completely remodel around a tooth, and for that tooth to be stable. The further a tooth moves, the longer it takes for it to stabilize.

There are other factors at play that tend to pull teeth back from whence they came! These include other fibres surrounding teeth that are attached to the gums. Don’t forget about the lips, cheeks and tongue that push on teeth and, oh yes, biting forces that are constantly in play that can influence the position of the newly positioned teeth. It’s because of all these variables that retainer wear is crucial whenever teeth are repositioned. In order for a tooth to stabilize, it needs to be held in its new position and not allowed to settle or shift. If someone just had their braces removed or just completed clear aligner wear (ie. Invisalign), and only wears their retainers a few nights a week, they will notice that some teeth may move a little and then the retainer pushes them back into position over night. In this example, that tooth is constantly moving back and forth almost daily. You can imagine that this poor tooth will never stabilize.

So the secret with retention is to wear your retainers enough so that you never notice any teeth moving, and when you place your retainer back in after it’s been out for a period of time, it is not tight. Another way to say it is that as long as your retainer goes in fully and without much pressure on your teeth, you will be fine. How much and how long do I have to wear my retainers? Well … I’m sorry to say there is no good answer to that question because everyone is different. Your orthodontist will follow up with periodic retainer checks to offer guidance to your retainer wear and offer recommendations to improve stability if needed. If you generally follow these instructions, your new smile will last a lifetime.