One of the treatments we
occasionally recommend prior to application of
"braces" is the
expansion of the upper arch in cases where it is very narrow and/or crossbites
exist. Crossbites are where the upper teeth fit inside the lower teeth. The analogy of shoes that are the right
size but too narrow works well here. Even though it is the right
size...you cannot get your foot all the way into a shoe that is too narrow.
The same holds true for the upper jaw and the amount of forward growth possible
in the lower jaw. When the upper jaw is narrow the mandible naturally will
stay back somewhat contributing to "overbite" development. (We actually call it
overjet, to
orthodontists overbite is the depth of overlap
of the front teeth... not forward displacement).
This appliance is called a Hyrax
Expander and is used at later developmental stages than the Quad
Helix Expander discussed on this site. It is usually at a
stage when a great deal of the growth is complete and correction rather than
guidance of that growth is needed. These are turned by someone at home
twice daily and are checked in the office at 7 days and again after the full 28
turns are done.
This is a view of a patient showing the completed
expansion and the development a very dramatic space
between the incisors. This is an indication of good palatal separation from this
orthopedic device but in most cases it is not nearly this large.
The space will usually spontaneously close within a few weeks by virtue of the
gum tissue fiber network around the teeth. By the time the braces are
placed at 3 months, it is usually a minimal space. In the most severe
spacings, like this one, we give the patient elastics to wear around the teeth
to aid in its closure.
TM
