How de we insert spacers?
Take 2 pieces of dental floss and a spacer.
Pass the dental floss in the center of the spacer (shapes like a donut) hold steadily between your fingers.
Pull both ends of the floss , the spacer will flatten and create a tension.
The spacer will be inserted the same way dental floss is used. Once inserted between the teeth. the floss with be slided out and the spacer will stay in place.
Spacers in place; see video here: