Abstract: Intrabuccal device includes two shells (2, 3) made of thermoformed plastic material, the first of which respectively covers the superior arch, and the second of which covers the inferior arch of the oral cavity. This device is provided with (rings and arms) (4a, 4b, 13a, 13b) that act on the said shells (2, 3) and can generate a mandibular propulsion force oriented in the direction of the mandibular propulsion and in the posteroanterior sense, so as to keep a shift of the mandible to the front of the maxilla, while allowing lateral movements.