Table 1.

Landmarks selected for airway analysis

Ba	Basion, the anterior margin of the foramen magnum
N	Nasion, the intersection of the internasal and frontonasal sutures in the midsagittal plane
Or L	Orbitale left, the most inferior anterior point on left orbit’s margin
Or R	Orbitale right, the most inferior anterior point on right orbit’s margin
PoL	Porion left, the most upper point on left bony external auditory meatus
PoR	Porion right, the most upper point on right bony external auditory meatus
S	Sella turcica, the centroid of Sella turcica
So	Midpoint of the Sella-Basion line
H	Hyoid bone, upper most point of the hyoid bone
E	Epiglottis, tip of epiglottis
D100	Point located at the 100% of the distance between E and Airway superior border plane, measured on the presurgical scan
D90	Point located at the 90% of the distance between D100 and Airway superior border plane