Table 4.
Descriptive statistics of dentoalveolar variables according to intervention groups at different timepoints
| Variables | Timepoint | RPE (N = 17) | MARPE (N = 19) | P value |
|---|---|---|---|---|
| PM-MW (mm) | T1-T0 | 3.48 ± 1.77†† | 4.40 ± 2.25†† | 0.175 |
| T2-T1 | − 1.31 ± 1.01†† | − 0.41 ± 0.51 | 0.002** | |
| T2-T0 | 2.16 ± 2.00 | 3.99 ± 2.46†† | 0.019** | |
| PM-IDW (mm) | T1-T0 | 6.17 ± 1.52†† | 6.33 ± 1.41†† | 0.594 |
| T2-T1 | − 0.25 ± 0.50 | − 0.66 ± 0.64†† | 0.071 | |
| T2-T0 | 5.92 ± 1.47† | 5.67 ± 1.43† | 0.602 | |
| M-MW (mm) | T1-T0 | 2.59 ± 1.17† | 3.31 ± 0.82† | 0.038* |
| T2-T1 | − 0.94 ± 0.61† | − 0.48 ± 0.70 | 0.043* | |
| T2-T0 | 1.65 ± 1.34† | 2.85 ± 0.98† | 0.004* | |
| M-IDW (mm) | T1-T0 | 6.11 ± 1.29† | 6.70 ± 1.10† | 0.150 |
| T2-T1 | − 0.58 ± 0.55 | − 0.53 ± 0.49 | 0.851 | |
| T2-T0 | 5.53 ± 1.47† | 6.18 ± 1.23† | 0.159 | |
| M-DI (°) | T1-T0 | 3.40 ± 2.47†† | 3.94 ± 1.61†† | 0.219 |
| T2-T1 | − 0.98 ± 1.25 | − 1.92 ± 1.61†† | 0.208 | |
| T2-T0 | 2.41 ± 2.55†† | 2.02 ± 1.11†† | 0.975 |
Descriptive statistics represented as mean ± standard deviation
†Indicate statistical significance with repeated measures analysis of variance with Bonferroni correction (α = 0.016)
†† Indicate statistical significance with Friedman’s analysis of variance by ranks (α = 0.05)
*Indicate statistical significance with independent t-test at each time point (P < 0.05)
**Indicate statistical significance with Mann–Whitney U test at each time point (P < 0.05)
Abbreviations: RPE, rapid palatal expansion; MARPE, mini-screw assisted rapid palatal expansion; T0, before treatment; T1, immediately after expansion; T2, after a 3-month consolidation period