Sometimes the orthodontist will use bands on the back molar teeth to provide additional support and to allow for different attachments. The bands are essentially metal rings that completely surround the teeth. Since most people's teeth do not have spaces between them, it would be nearly impossible or very difficult to place bands without spaces. It would also likely be painful for the patient. Therefore, one of the first steps in the process of placing bands is a short appointment to place separators or spacers. The appointment is needed a week prior to placing bands in order to provide room between the teeth.
Separators are small elastics (rubber bands) that are first stretched out with a special separator instrument. Then, they are simply flossed or pushed into the contact where space is needed. While the separator is being placed, the patient may feel slight pressure or a "pushing" sensation - this is due to the pressure needed to allow the rubber band to squeeze through the contact of the teeth.
Once the separators are in place, the patient will notice that they feel as though a piece of food is caught between their teeth. Usually within a few hours after placement, the soreness from tooth pressure/movement will begin but this dull achy feeling will normally soon subside.