The device (1) comprises a support intended to be placed in a patient's perioral area and comprises a generating member (10) of a gaseous fluid flow exerting a barrier effect between an inner area of the patient's mouth and the outside of the mouth； wherein the generating member (10) is formed by at least one duct that includes at one of its ends an aperture (12) which is placed in the exterior of the perioral area in front of said support (11) and is attached to the support (11) in a central portion thereof.
