[Problem] To make it possible to practice the perfect smile by simply wearing this mouthpiece. Also, to make it possible, with just this mouthpiece, for people with reduced oral function (primarily, the mouth muscles and/or tongue function required for eating, swallowing, and articulation) due to intractable neurological disorders, complications from brain disorders, or age, people who tongue thrust, and people for whom mouth/tongue calisthenics are recommended to learn correct mouth/tongue movements efficiently and easily without receiving continuous instruction from a specialist such as a physician or dentist. [Solution] This mouthpiece (1) has an upper-teeth contact part (2), an upper-lip contact part (3), and an upper-jaw contact part (4). The upper-teeth contact part (2) comprises a wall surface (2a) and a bottom surface (2b). A through-hole (5) is formed in said wall surface (2a). The upper-lip contact part (3) is provided on top of the wall surface (2a) so as to form a single unit therewith, and the top of said upper-lip contact part is concave. The upper-jaw contact part (4) is a member provided so as to form a single unit with the aforementioned bottom surface (2b), and a tip section (4a) of said upper-jaw contact part protrudes towards the upper rear of the mouthpiece (1).La présente invention a pour objectif de permettre lentraînement à un sourire parfait en portant tout simplement lembout buccal selon linvention. Elle permettra également, en utilisant tout simplement cet embout buccal, aux personnes atteintes dune fonction orale réduite (principalement, la fonction des muscles de la bouche et/ou de la langue nécessaire pour manger, déglutir, et articuler) due à des troubles neurologiques réfractaires, des complications de troubles cérébraux, ou à lâge, aux personnes présentant des poussées de la langue, et aux personnes pour lesquelles est recommandée une callisthénie de la bouche/langue, dapprendre des mouvements corrects de la bouche/langue de manière
