retractor
1. an instrument for maintaining operative exposure by separating the edges of a wound and holding back underlying organs and tissues; many shapes, sizes, and styles are available. See accompanying table.
2. any retractile muscle.
Emmet retractor, a self-retaining vaginal speculum.
Moorehead retractor, one for retracting the lips, cheeks, or margins of a surgical wound. It fits over the crown of the head and is provided with metal buttons, to which shields (or retractors) of desired shapes or sizes may be attached.