Table 3. Analysis of variables related to OIIEARR.
| Orthodontically induced inflammatory external apical root resorption (OIIEARR) | ||||||
|
None
(degree 0) |
Resorption (degree 1-2-3) | P value | None to mild resorption (degree 0-1) |
Severe resorption
(degree 2-3) |
P value | |
| n | 981 | 375 | 1155 | 201 | ||
| Pre-treatment age (years; mean ± SD) | 14.6±2.8 | 14.3±2.5 | 0.437a | 14.4±2.8 | 14.5±2.6 | 0.569a |
| Total treatment duration (months) | 26.7±9.4 | 30.3±9.4 | 0.000b* | 27.5±9.5 | 28.7±9.3 | 0.121b |
| Fixed orthodontic treatment duration (months) | 21.9±8.6 | 25.8±9.6 | 0.000b* | 22.9±0.9 | 23.89.0 | 0.198b |
| (treatment type) Two-phase treatment (n=455) |
n=335 73.6% |
n=120 26.4% |
0.191c |
n=387 85.1% |
n=68 14.9% |
0.372c |
|
(treatment type) One-phase treatment with fixed appliances (n=790) |
n=562 71.1% |
n=228 28.9% |
0.191c |
n=665 84.2% |
n=125 15.8% |
0.372c |
| Extraction (n=387) |
n=229 59.2% |
n=158 40.8% |
0.000c* |
n=329 85% |
n=58 15% |
0.000c* |
|
Non-extraction (n=969) |
n=751 77.5% |
n=218 22.5% |
0.000c* |
n=826 85.2% |
n=143 14.8% |
0.000c* |
aIndependent t test, bOne-way ANOVA, cChi-square test, *P < 0.05.