Mouth Gags

Mouth gags are used for forcible opening of the mouth, during operations in the oral cavity, for opening the mouth of a patient during an epileptic seizure, in trismus (see Tetanus), and during general anesthesia. The original model, still used today, was proposed by Heister and bears his name (figs. 1 and 2). Further improvements were made by Collin (fig. 3). The mouth is opened by slowly turning the screw, which causes the spreading of the levers R, inserted into the mouth (between the teeth). At present, the models shown in figs. 4-6 (models of König, Buchfeld, and O'Droyer-Denhart) are more commonly used, especially the last one, which provides better adaptation to the teeth and gums, thereby eliminating the danger of their injury.

For opening the mouth in post-scar contractions of the lower jaw (after noma or due to inflammatory processes in the joints of the lower jaw), cone-shaped or wedge-shaped R. made of hard wood (ebony) or rubber (figs. 7, 8), provided with screw threads, are used. Pitha proposed small rubber wedges (fig. 9). In the absence of special instruments, they can be replaced by a champagne cork sharpened at the end. In scar contractions of the lower jaw, expansion is performed by methodical repeated sessions. Sometimes only after many months of treatment is it possible to achieve the desired result.