This oral ventilation mask (1) comprises an elongate body (10) for channeling the respiratory exchanges of a patient carrying the mask, which body defines a first geometric axis (Z) and is provided, at one of its axial ends. opposed, intended in use to be turned towards the patient wearing the mask, a peripheral collar (15) covering the patient's mouth, which collar is provided with a sealing lip (16) adapted to be supported on the areas around the mouth, which are respectively between the nose and the upper lip of the patient, located to the right of the right commissure of the patient's lips, between the lower lip and the patient's chin, and located to the left of the left commissure of the patient's lips. In order to improve the sealing and the comfort of the mask, the collar has, on its side intended for use to be turned towards the patient, a rear face which carries the sealing lip so that, when the mask is not not worn, this rear face is substantially cylindrical, being centered on a second geometric axis, which is substantially perpendicular to the first axis, and the sealing lip runs on this rear face along a substantially elliptical path (E), the large axis (X16) is substantially perpendicular to the first axis and whose minor axis (Y16) is substantially parallel to the second axis. Ce masque buccal de ventilation (1) comporte un corps allongé (10) de canalisation des échanges respiratoires d'un patient porteur du masque, lequel corps définit un premier axe géométrique (Z) et est pourvu, à l'une de ses extrémités axiales opposées, destinée en service à être tournée vers le patient porteur du masque, d'une collerette périphérique (15) de recouvrement de la bouche du patient, laquelle collerette est munie d'une lèvre d'étanchéité (16) adaptée pour être appuyée sur les zones autour de la bouche, qui sont respectivement comprise entre le nez et la lèvre supérieure du patient, située à droite de la commissure droite des lèvres du patient, comprise entre
