Table 2: Pretreatment characteristics of the extraction group and the non-extraction group.
| Measurements | Extraction group(n = 30) Mean ± SD | Non-extraction group(n = 30) Mean ± SD | Significant difference between extraction and non-extraction groups P Value |
| Skeletal | |||
| SNA (deg) | 84.0 ± 3.6 | 83.9 ± 2.9 | 0.889 |
| SNB (deg) | 79.6 ± 3.4 | 77.7 ± 3.0 | 0.02* |
| ANB (deg) | 4.5 ± 2.2 | 6.3 ± 1.7 | 0.001** |
| SN-MP (deg) | 32.7 ± 4.6 | 32.3 ± 6.1 | 0.758 |
| SNPog (deg) | 78.7 ± 3.3 | 77.9 ± 3.6 | 0.362 |
| Pog to Y axis (mm) | 47.9 ± 9.5 | 44.5 ± 8.1 | 0.14 |
| Dental | |||
| U1-NA (deg) | 33.0 ± 6.5 | 27.3 ± 7.9 | 0.003** |
| U1-NA (mm) | 9.2 ± 2.3 | 5.9 ± 2.6 | 0.000** |
| L1-NB (deg) | 33.6 ± 5.0 | 30.5 ± 4.9 | 0.019* |
| L1-NB (mm) | 8.6 ± 2.4 | 7.5 ± 1.8 | 0.041* |
| Pharyngeal airway | |||
| PM-UPW (mm) | 19.2 ± 4.7 | 17.5 ± 4.7 | 0.172 |
| U-MPW (mm) | 10.7 ± 2.2 | 8.5 ± 2.6 | 0.001** |
| PASmin (mm) | 11.6 ± 3.5 | 8.9 ± 2.2 | 0.001** |
| V-LPW (mm) | 15.9 ± 2.4 | 14.5 ± 2.8 | 0.046* |
| Soft palate | |||
| NL/PM-U (deg) | 131.9 ± 6.1 | 132.1 ± 7.0 | 0.891 |
| PM-U (mm) | 32.0 ± 3.0 | 34.0 ± 3.8 | 0.029* |
| SP-T (mm) | 8.8 ± 1.2 | 9.4 ± 1.5 | 0.130 |
| Tongue position | |||
| H-VT (mm) | 34.1 ± 3.4 | 34.7 ± 3.7 | 0.526 |
| VT (mm) | 70.3 ± 5.9 | 69.0 ± 6.1 | 0.401 |
| V-CV (mm) | 19.4 ± 2.5 | 17.6 ± 2.7 | 0.01* |
| V-FH (mm) | 78.1 ± 6.2 | 80.9 ± 8.3 | 0.148 |
| Hyoid position | |||
| AH-CV (mm) | 31.6 ± 2.6 | 30.7 ± 3.1 | 0.251 |
| AH-FH (mm) | 80.8 ± 6.6 | 83.2 ± 7.5 | 0.187 |
*P ≤ 0.05; **P ≤ 0.01.