4. What are Orthodontic Spacers? Your orthodontist may have told you that you need to have spacers before your braces go on. What does this mean? Some of your teeth may need brackets that are attached to metal bands that go all the way around the tooth. * Usually, the bands are used only on molars. If the space between your molars is very tight, it will be difficult for the orthodontist to put the bands on the teeth. Therefore, space must be opened up to fit the bands in. This is where spacers come in.