Fig. 2
A Sagittal division of the upper airway; B 3D model of the upper airway and the intraoral space between the tongue and palate: green shown as the nasopharyngeal segment (the area from the roof of the airway to the plane of the posterior nasal spine); yellow shown as the velopharyngeal segment (the area from the plane of the posterior nasal spine to the plane passing through the apex of the soft palate); blue shown as the glossopharyngeal segment (the area from the plane of the apex of the soft palate to the plane passing through the apex of the epiglottis); pink is shown the laryngopharyngeal segment (the area from the apex of the epiglottis to the lowest plane of C4); brown is shown as the intraoral space between the tongue and palat; C Minimum cross-section of glossopharynx before treatment, the sagittal diameter L2 and transverse diameter L2 of the section; D Minimum cross-section of glossopharyngeal after treatment