Separators are a small rounded shaped elastics, placed between your teeth before applying orthodontic bands. They create space between teeth so that silver bands will fit easily on the back teeth. These are placed approximately a week before or some time at the same visit when braces are placed. They can come out if they made enough space or if you play with them. Sticky foods and chewing gum may also cause a separator to come out. If you lose a separator you should go back to your doctor to place them again.