| Curvature of NPC | Total | p value | |||||
| Slanted | Slanted Curved | Vertical | Vertical Curved | ||||
| Gender | Male | 74 | 23 | 4 | 3 | 104 | 0.779 |
| Female | 72 | 19 | 4 | 1 | 96 | ||
| Total | 146 | 42 | 8 | 4 | 200 | ||
| Percentage distribution | 73% | 21% | 4% | 2% | 100% | ||