The simple answer to this is to make sure that you wear your retainers!
The first person that we know who wrote about teeth moving after brace treatment was Dr Horowitz in 1926. He didn’t just talk about teeth moving after treatment but also about natural changes that happen after brace treatment. He called these “physiological movements” which are quite normal.
Some people ask if they should have their wisdom teeth removed. The problem with this is that the removal of these teeth can sometimes lead to tongue or lip numbness. As well as this we know that, on average, only 1mm of crowding is caused by wisdom teeth. This means that normal wear of retainers is better than having wisdom teeth removed and also is more comfortable.
When to Wear Retainers
We suggest for most people, who have had braces to wear removable, night-time retainers if possible. This should be enough to keep teeth straight in most cases. There are some situations where teeth are more likely to move after treatment. Rotated teeth and spacing in between teeth are two well known situations. If bone levels are lacking or if there are muscle attachments (called fraenal attachments) running between the teeth, then tooth movements are more likely.
Some treatments are carried out where stability is less easy to achieve because the orthodontist is trying to find the balance between aligning crowded teeth while also respecting the person’s face. In these situations and where teeth are trying to move, a bonded retainer, stuck to the teeth is more likely to hold the teeth in the long term. They work best when attached to the front 4-6 teeth. The failure rate of bonded retainers increases when taking them further back. There are two reasons for this; firstly there are more attachments that can fail and secondly the back teeth are used for crushing foods and are more likely to shear the retainer off.
When wearing a bonded retainer it is still worth wearing a night-time removable retainer as well. This helps to protect the bonded retainer but also gives an earlier sign if teeth are moving. Sometimes bonded retainers can fail and if you don’t notice, the first sign will be tooth movement.
How will I know if movements are starting to happen?
If you are wearing your removable retainer at night, there are a number of things you can look out for:
Does my retainer fit right up against my teeth? If this is the case, it is extremely unlikely that there is a problem. If it is not seating fully, this is a sign that the teeth are moving. Sometimes the teeth will ache if they are moving. Another sign is that the retainer feels tight when you are putting it back in at night. This is a sign that some movements are occurring during the daytime. The retainer will usually feel tighter before you can see tooth movements. If you find that this is happening, then wearing the retainers 24 hours a day ie full time except for cleaning the retainers and your teeth, can help to bring the teeth back into an improved position.
If this keeps happening and you are wearing retainers every night then bonded retainers may be the only alternative. We try to avoid bonded retainers if possible because they are more difficult to clean around.
If you miss a night of removable retainer wear and your teeth feel tighter when you put the retainer back in, or there is aching, this is a fairly sure sign that your teeth are on the move.
Not all movements are bad movements. After brace treatment the teeth are placed into a position where the front teeth are aligned but there are very small changes in the position of the back teeth as the bite finds its place following treatment. This causes some settling that is very minor and some and more significant in others. If this is happening the back of the retainer may start to drop down a little. This just means that the removable retainers will need replacing earlier, but then they should last for a much longer period because the bite settling has occurred.
Sometimes a series of unfortunate events can lead to loss of retainers. We have heard so often: “I put my retainers in a tissue when eating my food on the plane and when my tray was taken away, the retainers were taken away too!” Putting your retainers in tissue is a bad idea because it makes them look like rubbish. They are so light that another person will not know they are hidden amongst the layers of tissue.
When your retainers are not in your mouth, they should be put in a sturdy retainer box. Just ask us for one. You can also put your contact details on the box, just in case they are lost.
We have also seen the melting retainer: see our previous blog here. Removable retainers are heat formed and so they are thermoplastic. If they heat up, they will become warped. If they are left in a hot place even just for one day, they can start to melt. Always store them in a cool place, not on a window-sill in direct sunlight or near a radiator.
Pets, particularly dogs, love the smell of your retainers, so always keep them out of reach of pets. A dog will sniff them out, find them and chew them up!
It is important to have retainer reviews. This means that your orthodontist can pick up any early signs of problems that you may have missed.