| Fixed
braces, by definition, cannot be removed by the patient. They
consist of a series of small square 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. |