The invention relates to a functional dentofacial orthopedic apparatus (1) made of a flexible material and comprising two grooves, the general outer shape of each of which is a flared U when viewed horizontally, the two grooves being separated by a substantially horizontal partition (6). Each groove defines an alveolar canal (4, 5) encompassing the superior and inferior alveolodental arches, respectively, said canal (4, 5) consisting of a labial bar (2) and a lingual plate (3), as well as the horizontal partition (6), the inner surface of each canal being smooth. According to the invention, the apparatus includes: a continuous angled lingual ramp (10) which is intended for supporting and guiding the tongue toward the palate and the upper portion of which consists of a reinforced inner raised portion (9), the general shape of which is flared U and which extends over the inner circumference of the grooves. The cross-section of said raised portion gradually increases from a minimum value at the end of said raised portion to a maximum value in the central portion of the latter.
