| Group | Mean (mm) | Std. deviation (mm) | p-value |
| U6-U6 affected | 34.2 | 1.9 | 0.05 |
| Control | 36.3 | 2.9 |
|
| U5-U5 affected | 31.2 | 1.7 | 0.003 |
| Control | 34.3 | 2.5 |
|
| U4-U4 affected | 24.6 | 2.4 | 0.000 |
| Control | 28.9 | 2.5 |
|
| U3-U3 affected | 23.9 | 4.1 | 0.25 |
| Control | 25.3 | 2.0 |
|