The evolution of mouth gags. Presentation of a new modificated denhart mouth gag.

Mouth gags are surgical devices placed between the upper and the lower jaw to prevent the mouth from closing during operative procedures of the mouth or throat. Since the beginning of the use of mouth gags in medicine, a wide variety of different models has been invented and described. Till now, slipping, sliding and dislocation in the mouth are problems observed during use, especially of one-sided mouth gags. These problems were already discussed at the beginning of the ninteenth century. The need for introducing a suitable mouth gag is emphasized since then. A modification of the well known one-sided Denhart mouth gag is presented. The new Denhart-Hoefert mouth gag has pivotal pads, which allow to compensate movements in surgery without dislocation. These pivotal pads give a stable and better fixation to the teeth, to the edentulous jaws and enable also to fixate other instruments like tongue plates. The use of the Denhart-Hoefert mouth gag in practice showed a less frequency of sliding and dislocation, especially during manipulation. Besides the description of these modifications a short historic overview of the mouth gag discussion is presented.