Final answer:
Metal spring separators are inserted in the interdental space between teeth as part of orthodontic treatment to create necessary space for bands.
Step-by-step explanation:
Once inserted, metal spring separators are typically placed in the interdental space, which is the area between two adjacent teeth. These separators are usually part of orthodontic treatment to create space between teeth before the fitting of orthodontic bands. The separators push against the teeth on either side of the interdental space, creating a small gap which ensures that orthodontic bands can be placed without too much pressure on the teeth, potentially averting damage to the teeth or discomfort to the patient.