Fixed
braces, by definition, cannot be removed by the patient. They consist
of a series of small attachments cemented to the teeth. These are
known as brackets. It is simplest to think of each bracket as a
handle with which it is possible to control each tooth individually.The
brackets are highly sophisticated as every tooth has its own bracket
design engineered to achieve correct position and angle of axis.
How
are brackets controlled?
In the early part of treatment, a flexible but springy wire is
fitted to link up all the brackets. Because the teeth are irregular,
the wire has to bend up and down or in and out between the teeth.
This is the clever bit: the wire, a bi-product of NASA research,
has perfect shape memory and will gradually return to its original
shape, bringing the teeth with it. As treatment progresses, stiffer
wires are fitted and these act as a monorail. At this time, the
teeth are guided by tiny springs and elastics.
What
are the advantages of fixed appliances?
-
There is no plastic in the roof of the mouth. This means speech
is unaffected and the flavour of food can be enjoyed fully.
- The
temptation of not wearing the appliance does not arise.
- Fixed
braces are very good at fine tuning the way the teeth line
up and bite together.
What
are the disadvantages of fixed appliances?
-
Fixed braces are not very good at major alterations to the
bite. For this, other appliances are used either before or
at the same time as the fixed braces. Examples include upper
jaw widening or correcting the bite with a functional (orthopaedic)
appliance or a headgear.
- Fixed
braces are more noticeable. However, if this is a concern,
tooth coloured upper ceramic brackets make the appliance socially
very acceptable. For technical reasons, ceramic brackets are
not usually possible for the lower front teeth, but these
are not so noticeable anyway.
-
Cleaning the teeth takes more time, but has to be done.
- Certain
foods cannot be eaten (mainly foods you shouldn't be eating
anyway!) but this applies to al types of braces.
What
about playing sport or musical wind instruments?
-
It
is essential to wear a mouthguard when playing contact sports
such as rugby or potentially dangerous sports such as hockey,
whether wearing a brace or not. Ask your orthodontist about
the various mouthguards that we recommend in the Exeter Orthodontic
Practice.
-
The
problem area for players of wind instruments is the inner
surface of the lower lip. We provide low contour brackets
for the lower front teeth in such cases with good success.
2.
REMOVABLE APPLIANCES
Removable appliances are simple orthodontic appliances that can
be taken out of the mouth by the patient. They are constructed
of plastic and are held in place with small wire clips. These
days it is fair to say that removable braces are rarely the only
orthodontic appliance used during a course of treatment. They
can still be useful in patients with deep bites and for early
interceptive treatment.
An example of interceptive treatment is the forward guidance of
an upper incisor that has become trapped behind the lower teeth
when closing together. Crossbites such as this can also occur
at the back of the mouth and this can also be corrected by removable
appliance treatment.
Before
removable appliance therapy |
…..and
two visits later |
|
|
What
are the advantages of removable appliances?
-
They are relatively easy to keep clean
-
Appointments tend to be short
-
Removable appliances are still useful for tipping teeth and
for reducing overbites
What
are the disadvantages of removable appliances?
-
Limited range of tooth movements possible
-
The orthodontist has to rely on the patient wearing it correctly
or will not work
-
Affect speech and may cause lisping
-
For most malocclusions fixed appliances are better
3.
FUNCTIONAL APPLIANCES
There
are many types of functional appliances, mainly to treat underdeveloped
lower jaws. The one most frequently used in the Exeter Orthodontic
Practice is called the “Twin Block” appliance. These
braces work by holding the lower jaw in a forward position for
between 6 to 12 months.
These braces, if worn correctly, can be very effective at changing
the way the teeth bite together. But they do not necessarily stimulate
much extra growth in the jawbone. Many studies have been carried
out that show that the long-term change in the bite is mainly
due to a backward movement of the upper teeth and a forward movement
of the lower teeth in relation to the jawbone. A smaller proportion
of the change in the bite can be due to an effect on the growth
of the bones of the face.
| Before
treatment with twin blocks |
after
twin blocks and fixed appliances |
|
|
|
|
