Mean values by sex.
| Variable | Female | Male | P Value |
| Age | 114 | 108 | 0.56 |
| BDI | 6.7 | 7.4 | 0.06 |
| ADI | 2.3 | 3.1 | <0.001 |
| PADI | 17.8 | 19.1 | 0.003 |
| B-C1 | 28.2 | 29.8 | 0.008 |
| Op-C1 | 39.0 | 41.7 | 0.001 |
| Powers ratio | 0.72 | 0.71 | 0.46 |
| CCI-r | 2.5 | 3.0 | 0.002 |
| CCI-l | 2.4 | 3.1 | <0.001 |
| LMI-r | 2.9 | 3.4 | <0.001 |
| LMI-l | 3.1 | 3.4 | 0.002 |
Statistically significant findings appear in boldface.
ADI, atlanto-dens interval; B-C1, basion-to-C1 distance; BDI, basion-dens interval; CCI, condylar-to-cervical spine interval; l, left; LMI, lateral mass interval; Op-C1, opisthion-to-C1 distance; PADI, posterior atlanto-dens interval; r, right.