Table 5. Influencing factors on decreases of the mandibular intercanine, inter first and second premolar, and inter first and second molar distances over the five-year post-treatment period.
Influencing factors (age, sex, maxillary expansion before bone grafting, space closure of the missing maxillary lateral incisor, absence of mandibular premolars, and GOSLON score after treatment (T0) on decreases of mandibular intercanine (D33), inter first-premolar (D44), inter second-premolar (D55), inter first-molar (D66), inter second-molar (D77) distances during the first two years after treatment (T0-T2), from two to five years after treatment (T2-T5), and for the whole five-year period after treatment(T0-T5) (Linear regression test).
| Decreases of mandibular distances | T0 –T2 | T2 –T5 | T0 –T5 | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| D33 | D44 | D55 | D66 | D77 | D33 | D44 | D55 | D66 | D77 | D33 | D44 | D55 | D66 | D77 | ||
| (R2) | 0.21 | 0.15 | 0.07 | 0.07 | 0.15 | 0.06 | 0.06 | 0.09 | 0.14 | 0.25 | 0.13 | 0.08 | 0.05 | 0.08 | 0.14 | |
| Age | – | – | ||||||||||||||
| Sex (girl=0, boy=1) | − | |||||||||||||||
| Maxillary expansion (yes=0, no=1) | + | |||||||||||||||
| Maxillary expansion (yes=0, unknown=1) | + | |||||||||||||||
| Space closure (no=0, yes=1) |
+ | + | – | + | ||||||||||||
| Premolar absence (no=0, yes=1) | – | + | ||||||||||||||
| GOSLON at T0 | + | |
|
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− | – | |
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Notes.
+ : 0.05 ≤p ≤ 0.2 with positive effect; + : p < 0.05 with positive effect.
- : 0.05 ≤p ≤ 0.2 with negative effect; − : p < 0.05 with negative effect.