Table 4 Distribution of the root length reduction during orthodontic treatment of the individual teeth (upper and lower incisors, canines, first molars) (each n = 100, overall n = 1600): post-treatment RCR relative to pre-treatment RCR (rRCR), absolute (n) and relative (%) frequencies
From: Apical root resorption during orthodontic treatment with aligners? A retrospective radiometric study
| Â | Tooth | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
rRCR | 16 | 13 | 12 | 11 | 21 | 22 | 23 | 26 | 46 | 43 | 42 | 41 | 31 | 32 | 33 | 36 |
rRCR < 80 | 7 | 12 | 6 | 10 | 7 | 2 | 7 | 8 | 1 | 2 | 1 | 10 | 14 | 5 | 6 | 3 |
7.0 | 12.0 | 6.0 | 10.0 | 7.0 | 2.0 | 7.0 | 8.0 | 1.0 | 2.0 | 1.0 | 10.0 | 14.0 | 5.0 | 6.0 | 3.0 | |
80 ≤ rRCR < 90 | 11 | 11 | 15 | 11 | 12 | 11 | 16 | 8 | 9 | 9 | 18 | 15 | 12 | 11 | 7 | 14 |
11.0 | 11.0 | 15.0 | 11.0 | 12.0 | 11.0 | 16.0 | 8.0 | 9.0 | 9.0 | 18.0 | 15.0 | 12.0 | 11.0 | 7.0 | 14.0 | |
90 ≤ rRCR < 100 | 22 | 24 | 28 | 22 | 22 | 29 | 27 | 36 | 38 | 31 | 25 | 27 | 25 | 32 | 24 | 33 |
22.0 | 24.0 | 28.0 | 22.0 | 22.0 | 29.0 | 27.0 | 36.0 | 38.0 | 31.0 | 25.0 | 27.0 | 25.0 | 32.0 | 24.0 | 33.0 | |
rRCR ≥ 100 | 60 | 53 | 51 | 57 | 59 | 58 | 50 | 48 | 52 | 58 | 56 | 48 | 49 | 52 | 63 | 50 |
60.0 | 53.0 | 51.0 | 57.0 | 59.0 | 58.0 | 50.0 | 48.0 | 52.0 | 58.0 | 56.0 | 48.0 | 49.0 | 52.0 | 63.0 | 50.0 | |
Total (n) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |