Table 3.
Descriptive statistics of skeletal variables according to intervention groups at different timepoints
| Variables | Timepoint | RPE (N = 17) | MARPE (N = 19) | P value |
|---|---|---|---|---|
| FZS (mm) | T1-T0 | 0.36 ± 0.52 | 0.05 ± 0.38 | 0.076 |
| T2-T1 | − 0.21 ± 0.62 | 0.10 ± 0.48 | 0.100 | |
| T2-T0 | 0.14 ± 0.52 | 0.15 ± 0.58 | 0.962 | |
| ZMS (mm) | T1-T0 | 1.04 ± 1.01† | 1.49 ± 0.83† | 0.157 |
| T2-T1 | − 0.14 ± 0.80 | − 0.07 ± 0.61 | 0.697 | |
| T2-T0 | 0.89 ± 0.83† | 1.41 ± 0.87† | 0.080 | |
| PM-NW (mm) | T1-T0 | 2.18 ± 0.99† | 2.66 ± 0.63† | 0.098 |
| T2-T1 | − 0.63 ± 0.43†† | − 0.47 ± 0.40†† | 0.285 | |
| T2-T0 | 1.55 ± 1.02† | 2.19 ± 0.84† | 0.045* | |
| M-NW (mm) | T1-T0 | 1.95 ± 0.81† | 2.88 ± 0.82† | 0.002* |
| T2-T1 | − 0.70 ± 1.26†† | − 0.40 ± 0.34 †† | 0.827 | |
| T2-T0 | 1.23 ± 1.66 | 2.48 ± 0.84†† | 0.003** | |
| NPF (mm) | T1-T0 | 2.85 ± 1.95† | 3.22 ± 1.20† | 0.495 |
| T2-T1 | − 1.42 ± 1.28†† | − 1.15 ± 1.42†† | 0.346 | |
| T2-T0 | 1.43 ± 1.50† | 2.07 ± 1.37† | 0.199 | |
| GPF(mm) | T1-T0 | 1.84 ± 1.31† | 2.70 ± 1.18† | 0.048* |
| T2-T1 | 0.31 ± 1.05 | − 0.30 ± 0.75 | 0.639 | |
| T2-T0 | 1.52 ± 0.85† | 2.40 ± 0.96† | 0.008* |
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