In the context of surgery or dental surgery, a gag is a device used to hold the patient's mouth open when working in the oral cavity, or to force the mouth open when it cannot open naturally because of forward dislocation of the jaw joint's intraarticular cartilage pad. Applications for medical gags include oral surgery and airway management. Gag designs, like other medical instrument designs, are often named after their inventors. Common examples of medical gags include the Jennings, Whitehead, and Hallam gags.
These type of gags are also used in sexual fetish or bondage play. See Gag (BDSM)#Medical.