The present invention provides a mouthpiece assembly for establishing a protected airway for a patient. The mouthpiece assembly comprises a generally elliptical tubular bite block having a generally elliptical passageway formed therethrough. The mouthpiece assembly further comprises a generally elliptical front shield attached to the front end of the tubular bite block portion. The front shield has a central opening in communication with the passageway for receiving medical instruments therethrough and a strap opening adjacent each of the opposing edge portions. At least a portion of the front shield is curved rearward and is flexible to allow the at least a portion of the front shield to conform to the patient's facial structure. The mouthpiece assembly also comprises a tongue depressing member extending rearwardly and downwardly from the rearward end of the bottom wall of the tubular bite block, and a resilient cushioning sleeve formed around at least a portion of the tubular bite block. A headstrap has an elongate belt member adapted for insertion through the strap openings to connect the belt ends to the front shield.