Mean and SD of the angle acquired from the reference lines of the 223 midsagittal brain MR images vs the ACPC line^*

Reference Lines	Angle Difference to the ACPC Line	SD
TS-EOP line	0.0°	±4.0°
TS-IOP line	0.8°	±3.2°
OML	−12.6°	±4.2°

Note:—ACPC indicates anterior/posterior commissure; TS-EOP, tuberculum sellae and external occipital protuberance; TS-IOP, tuberculum sellae and internal occipital protuberance; OML, orbitomeatal line.

^*P value: .236 (TS-EOP line vs TS-IOP line), 0 (TS-EOP line vs OML and TS-IOP line vs OML)