Cephalometric landmarks and linear measurements. Landmarks: nasion (N); sella (S); anterior nasal spine (ANS); point A; posterior nasal spine (PNS); point B; tip of uvula (U); inferoanterior point on the fourth cervical (C4); inferoanterior point on the second cervical (C2); most superior and anterior point on the hyoid bone (H); most superior point on the epiglottis (E); and Pogonion (Pog). The X-axis was constructed by drawing a line through the N, 7° above the SN line; the Y-axis was constructed by drawing a line through S, perpendicular to the X-axis. Linear distances: 1: NOP; 2: UOP, 3: TOP, 4: EOP, 5: SPL, 6: SPW. Angle measurement: 7: palatal angle, 8: C2C4-SN angle, ANB angle.