Museum and Archive | Collection | Fixed Appliances | Twin wire

Twin wire

Twin wire
Joseph E. Johnson developed the twin wire technique in 1929. It was based on the principle that two light (.010 inch) wires would work more physiologically that one heavy wire. Both wires were inserted into the same channel, which was fastened with a ligature wire or a cap. The twin wire had the advantage of being more comfortable than other techniques but it lacked control of the canines and premolars and was unsuitable for extraction cases.

Upper model showing Johnson Twin Wire arch appliance on plaster base, c. 1950