Table 3: Treatment effects of the extraction group and the non-extraction group.
| Measurements | Extraction group (n = 30) | Non-extraction group (n = 30) | ||||
| Pre-treatment (mean ± SD) | Post-treatment (mean ± SD) | P | Pre-treatment (mean ± SD) | Post-treatment (mean ± SD) | P | |
| Skeletal | ||||||
| SNA (deg) | 84.0 ± 3.6 | 83.8 ± 3.3 | 0.275 | 83.9 ± 2.9 | 83.0 ± 2.8 | 0.012* |
| SNB (deg) | 79.6 ± 3.4 | 79.7 ± 3.5 | 0.924 | 77.7 ± 3.0 | 77.6 ± 3.2 | 0.799 |
| ANB (deg) | 4.5 ± 2.2 | 4.1 ± 2.4 | 0.073 | 6.3 ± 1.7 | 5.4 ± 2.0 | 0.001** |
| SN-MP (deg) | 32.7 ± 4.6 | 33.4 ± 4.8 | 0.003** | 32.3 ± 6.1 | 33.3 ± 6.7 | 0.002** |
| SNPog (deg) | 78.7 ± 3.3 | 79.6 ± 3.4 | 0.000** | 77.9 ± 3.6 | 78.1 ± 3.7 | 0.539 |
| Pog to Y axis (mm) | 47.9 ± 9.5 | 49.9 ± 10.5 | 0.000** | 44.5 ± 8.1 | 45.3 ± 9.1 | 0.210 |
| Dental | ||||||
| U1-NA (deg) | 33.0 ± 6.5 | 17.5 ± 6.4 | 0.000** | 27.3 ± 7.9 | 22.3 ± 5.6 | 0.000** |
| U1-NA (mm) | 9.2 ± 2.3 | 3.4 ± 2.1 | 0.000** | 5.9 ± 2.6 | 4.7 ± 2.3 | 0.004** |
| L1-NB (deg) | 33.6 ± 5.0 | 26.4 ± 8.4 | 0.000** | 30.5 ± 4.9 | 40.1 ± 6.4 | 0.000** |
| L1-NB (mm) | 8.6 ± 2.4 | 6.1 ± 2.8 | 0.000** | 7.5 ± 1.8 | 10.0 ± 2.3 | 0.000** |
| Pharyngeal airway | ||||||
| PM-UPW (mm) | 19.2 ± 4.7 | 19.6 ± 4.3 | 0.068 | 17.5 ± 4.7 | 18.6 ± 4.7 | 0.012* |
| U-MPW (mm) | 10.7 ± 2.2 | 10.5 ± 2.3 | 0.525 | 8.5 ± 2.6 | 9.2 ± 2.4 | 0.079 |
| PASmin (mm) | 11.6 ± 3.5 | 10.8 ± 2.8 | 0.141 | 8.9 ± 2.2 | 8.7 ± 2.1 | 0.768 |
| V-LPW (mm) | 15.9 ± 2.4 | 16.7 ± 2.5 | 0.103 | 14.5 ± 2.8 | 15.9 ± 2.6 | 0.032* |
| Soft palate | ||||||
| NL/PM-U (deg) | 131.9 ± 6.1 | 131.5 ± 5.9 | 0.667 | 132.1 ± 7.0 | 130.8 ± 6.2 | 0.070 |
| PM-U (mm) | 32.0 ± 3.0 | 32.3 ± 2.8 | 0.084 | 34.0 ± 3.8 | 34.6 ± 3.8 | 0.025* |
| SP-T (mm) | 8.8 ± 1.2 | 8.9 ± 1.2 | 0.668 | 9.4 ± 1.5 | 9.7 ± 1.7 | 0.017* |
| Tongue position | ||||||
| H-VT (mm) | 34.1 ± 3.4 | 35.7 ± 3.1 | 0.004** | 34.7 ± 3.7 | 37.4 ± 3.0 | 0.002** |
| VT (mm) | 70.3 ± 5.9 | 70.8 ± 6.2 | 0.592 | 69.0 ± 6.1 | 72.7 ± 6.1 | 0.001** |
| V-CV (mm) | 19.4 ± 2.5 | 19.9 ± 2.7 | 0.174 | 17.6 ± 2.7 | 19.4 ± 2.5 | 0.007** |
| V-FH (mm) | 78.1 ± 6.2 | 86.3 ± 7.4 | 0.000** | 80.9 ± 8.3 | 87.8 ± 10.6 | 0.000** |
| Hyoid position | ||||||
| AH-CV (mm) | 31.6 ± 2.6 | 33.4 ± 3.8 | 0.001** | 30.7 ± 3.1 | 32.0 ± 2.9 | 0.007** |
| AH-FH (mm) | 80.8 ± 6.6 | 88.0 ± 8.1 | 0.000** | 83.2 ± 7.5 | 89.4 ± 11.0 | 0.000** |
*P ≤ 0.05; **P ≤ 0.01.