Retention
After active orthodontic treatment when the teeth are straight, the
fixed appliances are removed. If nothing is done at this stage the teeth
have a tendency to return towards their initial position. In addition,
if you are young and your teeth and jaws are still growing, the teeth
may move and re-crowd.
Retainers
 To
prevent the teeth moving it is usual to wear retainers - retaining
braces until the teeth reduce their tendency to move. In reality, teeth
tend to move throughout life and re-crowding of the front teeth,
especially the lowers, is a natural ageing process.
Faithful wearing of retainers can minimise unwanted changes in the
position of teeth but it is important to follow the instructions you are
given.
Conventional
removable retainers, known as Hawley retainers after their original
designer, are made of wire and acrylic. They are reasonably robust but
can fracture is mishandled or abused. However, if the damage is not too
great, they are relatively easy to repair. |
Although
this retainer looks flimsy, in practice it is more robust than the wire
and acrylic retainer. It is also more comfortable to wear and nearly
invisible. As an added bonus, because it is such a good fit, it is
usually worn for fewer hours during the day than the conventional
retainer. 
Sometimes
it is preferable to fit a fixed retainer, which is a thin wire glued to
the inside of the teeth. These perform well for the lower front teeth
but are more prone to damage behind the upper front teeth. They may be
left in place indefinitely provided that good oral hygiene can be
maintained.