Table 2.
Various linear parameters and ratio used to determine the normal vertical positions of S and N points.
| Variables | Gender | Values mean ± SD | Significance (P value) Males vs females |
|---|---|---|---|
| S-Ba distance (mm) | Males | 45.69 ± 3.13 | 0.000∗∗∗ |
| Females | 42.75 ± 2.96 | ||
| Total | 44.10 ± 3.36 | ||
|
| |||
| S-Ar distance (mm) | Males | 35.46 ± 2.89 | 0.000∗∗∗ |
| Females | 32.37 ± 2.70 | ||
| Total | 33.79 ± 3.18 | ||
|
| |||
| S-Ptm distance (mm) | Males | 35.98 ± 3.04 | 0.000∗∗∗ |
| Females | 33.27 ± 2.44 | ||
| Total | 34.52 ± 3.04 | ||
|
| |||
| S-PNS distance (mm) | Males | 46.44 ± 3.38 | 0.000∗∗∗ |
| Females | 43.33 ± 2.68 | ||
| Total | 44.77 ± 3.38 | ||
|
| |||
| Ar-Ptm distance (mm) | Males | 35.26 ± 3.01 | 0.000∗∗∗ |
| Females | 32.78 ± 2.21 | ||
| Total | 33.92 ± 2.88 | ||
|
| |||
| Ar-PNS distance (mm) | Males | 38.78 ± 3.23 | 0.000∗∗∗ |
| Females | 36.22 ± 2.55 | ||
| Total | 37.40 ± 3.14 | ||
|
| |||
| Ba-Ptm distance (mm) | Males | 43.80 ± 3.39 | 0.000∗∗∗ |
| Females | 41.54 ± 2.81 | ||
| Total | 42.58 ± 3.25 | ||
|
| |||
| Ba-PNS distance (mm) | Males | 44.70 ± 6.66 | 0.060∗ |
| Females | 42.94 ± 2.96 | ||
| Total | 43.75 ± 5.07 | ||
|
| |||
| S-FH distance (mm) | Males | 18.28 ± 2.26 | 0.000∗∗∗ |
| Females | 16.70 ± 1.93 | ||
| Total | 17.43 ± 2.23 | ||
|
| |||
| N-FH distance (mm) | Males | 26.33 ± 2.41 | 0.053NS |
| Females | 25.51 ± 2.16 | ||
| Total | 25.89 ± 2.30 | ||
|
| |||
| S-FH:N-FH ratio (%) | Males | 0.69 ± 0.07 | 0.002∗∗ |
| Females | 0.65 ± 0.06 | ||
| Total | 0.67 ± 0.06 | ||
Ba, basion; Ar, articulare; S, sella; Ptm, pterygomaxillary fissure; PNS, posterior nasal spine; FH, Frankfort horizontal plane. SD = standard deviation, NS = nonsignificant, ∗ = P < 0.05,∗∗ = P < 0.01, ∗∗∗ = P < 0.001.