This topic is related to extractions for orthodontics. If there is a moderate amount of crowding that is not enough to warrant extractions but too much to safely align the teeth then IPR may be indicated. A small amount of enamel from between the teeth is removed to reduce their width. This is also known as reproximation, slenderizing, stripping, enamel reduction or selective reduction. The x-rays are examined to determine if there is sufficient enamel thickness. A very thin diamond disc or strip is slid between the teeth to remove a fraction of a millimeter. The reduction is normally carried out over several teeth until enough space is gained to allow alignment. This may be accomplished over several appointments and may also be used to gain space for realignment so that retainers fit better.