Table 2.
Descriptive and inferential statistics of radicular length changes occurred after maxillary expansion
| T0–T1 (mm) | ||||||||
|---|---|---|---|---|---|---|---|---|
| TB group | BB group | |||||||
| Teeth | n | Mean | SD | p value* | Mean | SD | p value* | p value** |
| P1 | 20 | 0.31 | 0.16 | p < 0.05 | 0.04 | 0.02 | p < 0.05 | p < 0.05 |
| P2 | 20 | 0.23 | 0.12 | 0.07 | 0.03 | p < 0.05 | ||
| M1m (c) | 20 | 0.22 | 0.10 | 0.07 | 0.03 | p < 0.05 | ||
| M1d (d) | 20 | 0.25 | 0.15 | 0.06 | 0.02 | p < 0.05 | ||
| M1p (e) | 20 | 0.33 | 0.19 | 0.11 | 0.04 | p < 0.05 | ||
P1 first premolar; P2 second premolar; M1m first molar mesial root; M1d first molar distal root; M1p first molar palatal root; TB tooth borne; BB bone borne; T0 pre-treatment; T1 post-retention; n number of teeth; SD standard deviation
p value* based on one-way analysis of variance (ANOVA) for intra-group comparison (different teeth) and set at p < 0.05; post hoc assessment performed according to the Bonferroni’s multiple comparisons test
p value** base on independent Student’s t test for inter-group comparisons and set at p < 0.05