Table 4.
Treatment duration segregated by severity of malocclusion and appliance.
| Severity of malocclusion | Appliance (group) | N (%) | Treatment duration (month), Mean [SD] | Min | Max | Median | P-value |
|---|---|---|---|---|---|---|---|
| S1 | A | 364 (92.62%) | 20.64 [7.12] | 3.68 | 40.48 | 19.84 | 0.001 |
| B | 181 (76.37%) | 22.75 [7.33] | 3.25 | 41.89 | 22.14 | ||
| S2 | A | 29 (7.38%) | 26.09 [7.93] | 11.97 | 41.40 | 25.99 | 0.003 |
| B | 56 (23.63%) | 31.06 [6.65] | 16.01 | 44.39 | 31.93 | ||
| All groups | 630 | 22.42 [7.77] | 3.25 | 44.39 | 21.38 |
A chi-square-test indicates significantly (P < 0.0001) higher proportions of treatment complexities judged as ‘severe’ (S2) for Incognito. Therefore, the factor‚ ‘severity of malocclusion’ was included in the ANOVA as a main factor. Accordingly, there was a significant difference in treatment duration between the appliance types (A, WIN; B, Incognito), in both classifications S1 and S2, independent of the classification of treatment complexities.