A surgical mask for use in dental procedures, and oral or facial surgery, formed of a continuous sheet of flexible material comprising a nose-conforming shell incorporating adhesive material for sealing and for maintaining position on the patient during the dental or surgical procedure. The mask forms an encasement for input/output manifolds, and terminates in flexible flange at the columella-labial junction； the mask includes a manifold for receiving and directing N2O/O2 into the nasal vault of the patient, and for the removal of exhalant and the scavenging of gases from the work area.
