You have now had orthodontic treatment and your teeth are ‘straight’: where do you go from here? This leaflet is here to tell you how to maintain your newly straightened smile.

Tooth Movement

When a force is applied to a tooth, the bone and supporting structures around the tooth are stimulated into action, leading to re-modelling of bone.

After 1-2 weeks of pressure, the bone undergoes significant changes, and the tooth begins to move slowly but surely.  

As the tooth moves, the bone in front of it is removed, and the space behind it is filled with a gel that will eventually become bone, but this is a slow process taking several months.

There are elastic fibres around teeth, and many of them are pulled tight as the tooth moves, so there is an elastic force pulling the tooth back to where it came from; the gel offers little resistance. This is why teeth take a few weeks to start moving and will readily relapse, i.e return towards their previous positions.

Similarly, if the orthodontic appliance isn’t worn enough each day, the teeth move in the right direction whilst it is in and then relapse when it is out. The critical time seems to be 12-14 hours. More than this and progress is seen, less and the movement is slow. 

When the teeth are in the correct position, then it take 6-9 months for the fibres to remodel and relax, and 9-12 months for the bone to reform; the relapse problem is reduced at 12 months and greatly reduced at 2 years.
Recent research has shown the problem is a tendency over your lifetime for the teeth to drift forwards, causing the crowding to recur.

It is clear from the research that for the teeth to remain in the correct position, then they need to be retained for at least 2 years. As there are tendencies for crowding to reoccur for the rest of your life, ongoing lifetime retention is the safest option to avoid any risk of relapse.

The only way to be sure to keep your teeth straight is to retain forever.

Guidelines for VFR’s (Vacuum Formed Retainers)

From the end of treatment:

  • Full time retention for 3 months
  • Nighttime wear for the balance of a year from treatment finishing
  • Twice weekly wear at night for second year
  • Check retainer every 2-4 weeks thereafter for ‘tightness’. If there is some tightness, then go nightly for 3 months.
  • If teeth persist in relapsing after 12-18 months, then permanent retention might be required.

Retainers generally last 2-3 years, so replacement costs are not insignificant.

Options & Provisos

We provide a fixed and/or vacuum formed retainer (VFR) as routine to all orthodontic patients at the end of treatment (see over). A VFR is a thin (0.75mm) but stiff transparent plastic shell moulded to fit your new teeth.

VFR’s usually last 1-2 years so you will need to have them replaced every few years at your own expense.
The plaster model used to make the VFR is usually not reusable - on request we can take an additional impression so another can easily be constructed, or for an additional fee we can take a 3D scan that can be used to make multiple VFR’s.

If you lose or break the VFR then it would be wise to arrange a replacement quickly, particularly in the first year as it is tricky to reposition teeth that have moved.

We will provide a replacement VFR or repair a fixed retainer for 12 months after treatment is completed.

Permanent retention

Ideally, we would place a formed wire around the back of the front teeth and bond it to each tooth with tooth coloured plastic.

It is not always possible owing to tight or well-worn in bites. In most cases we would also provide a vacuum formed retainer that fits over the wire as a ‘belts & braces backstop’

If a tooth becomes detached from the wire, relapse can occur, but this is rare.

If you feel a tooth is moving or something feels ‘odd’, you should see us or your usual dentist as a matter of moderate urgency.

There seems to be few problems with the wire, and we do not see any greatly increased problems with gum disease or decay. Most patients report that they rapidly become used to the wire.

The survival rate is believed to be 10 years plus, and repair and replacement is usually possible.

Newer developments include a laser cut retainer and a milled resin retainer.

Care of Vacuum Formed Retainers

Brush the retainers with cold water every time you brush your teeth. We sell a product to clean your retainers.

Retainers can easily be broken if they are not in your mouth or in their case. Avoid backpacks, back pockets, table tops and places where the family pet can reach them.

If you break your retainer, do not try to fix it yourself. Call us for an appointment. The odd wear hole is not important.

Retainers do not like heat. Avoid hot water, sunlight, and do not microwave them or place them in hot water (yes, it has been done!)

You may talk funny or salivate more when you first get your retainer. This is normal and will improve rapidly with practice and time. They are usually stiff to start with but loosen after the first few days.

If there is a sharp edge, try trimming with nail scissors or filing with an emery board or nail file.