Mean (SD) values for the outer diameter (OD) and inner diameter (ID).
| Cohort | OD Right (mm) | OD Left (mm) | ID Right (mm) | ID Left (mm) |
| Combined | 6.6 (1.3) | 6.8 (1.3) | 3.5 (1.2) | 3.8 (1.3) |
| New Zealand European | 6.5 (1.3) | 6.7 (1.3) | 3.4 (1.3) | 3.7 (1.2) |
| Māori | 6.8 (1.2) | 7.0 (1.2) | 3.7 (1.2) | 4.0 (1.2) |
| P value | 0.09 | 0.16 | 0.16 | 0.12 |
Note: Statistical analysis by Student t test.