Abstract: A dental mouth prop for maintaining the jaws of a dental patient in an opened condition includes a body for isolating a posterior tooth to be worked upon and for facilitating the evacuation of saliva and other fluids from the region of the mouth around the isolated tooth. The body includes a sidewalls positionable on opposite sides of the tooth to be worked upon and which are joined together so as to form a workspace-defining cavity between the sidewalls. The body also includes hollow portions positionable adjacent the gum tissue of the mandibular arch for collecting and extracting fluids which migrate to the region adjacent the isolated tooth. The prop also includes a bite flap member engageable by the teeth of the mandibular or maxillary arch opposite the tooth to be worked upon and which is pivotally attached to the prop body to accommodate pivotal movement of the flap member to a position corresponding to the occlusal bite plane of the engaging teeth.