Landmarks used in this study. (1) N: nasion; (2) S: sella; (3) Or: orbitale; (4) P: porion; (5) Ar: articulare; (6) Ba: basion; (7) PNS: posterior nasal spine; (8) ANS: anterior nasal spine; (9) A: A point; (10) B: B point; (11) Go: gonion; (12) RGn: most protrusive point of retrognathion; (13) Me: menton; (14) C3: most anterior and inferior point of the third cervical vertebra; and (15) Hy: most anterior and superior point on the body of the hyoid bone.