The time zones known as Greenwich Mean Time and the International Date Line are sometimes alternatively used to demark the western from eastern hemispheres, but the would not be true hemispheres as those time zones are not straight longitudes.
The final part of braces are interarch rubber bands, which are used to adjust bite and jaw position. These are connected to the brackets with hooks, often connecting the top tooth bracket with the bottom tooth bracket to help adjust the position of the teeth in the mouth and the position of the jaw.
Bands are cemented and brackets are bonded to the front of your teeth. Every 4 to 8 weeks, adjustments are made to the braces by way of wire-changers, adding springs, elastics or other accessories. Accessories are necessary to make your braces work.