For the inspection of the oral cavity to view a mirror image of teeth in locations of the mouth where visibility is difficult or impossible. they are also used for reflecting light into desire surfaces, indirect vision, and for the retraction of soft tissues to improve access or vision.
The reflection layer is at the glass underside and the image is reflected from below the glass surface. More durable as they coated on the back surface, protected by the glass. Regular mirrors reflect light from the top of the glass as well as from the silver layer. This could cause a double image. Simple stem mirror heads have a shank that is straight