Fergusson's Mouth Gag This is a Fergusson or Ackland type mouth gag. It is made of stainless steel, as indicated by the marking on one jaw, and has an overall X-shape. The instrument is equipped with serrated tooth plates and a plier-style handle that features a spring system and ratcheted stems. Mouth gags are typically used to keep a patient’s mouth open during surgery. If anaesthetics are administered through a tube inserted into the trachea, the mouth gag assist into avoid the chance of obstructing the flow of anaesthetic. The gag might also have been used to keep the mouth open during specific surgeries, such as tonsil removal. 1925-1975