Figure 2. The MAD projects the mandible: A) without projection, B) with projection. Airway space volume (AS) increases (arrows) and/or an improvement in pharyngeal wall tone occurs. This is due to the advancement of the tongue (T) and other para-mandibular soft tissues; even the collapse of the soft palate (SP) undergoes improvement. The overjet (C, in red) decreases over the years (D), by projection of the lower teeth and retraction of the upper ones (arrows).