Table 1.
Summary data for each of the grades of periodontal ligament visibility (PLV). f = female, m = male UK Caucasian data
| n-tds | -tds | sd-tds | min-tds | 25th%ile | 50th%ile | 75th%ile | max-tds | 18-year threshold | p < 18 | p > 18 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Females | |||||||||||
| PLV-Af | 8 | 19.57 | 1.83 | 16.33 | 18.23 | 20.28 | 20.60 | 22.06 | 14.20 % | 0.142 | 0.858 |
| PLV-Bf | 202 | 21.25 | 2.16 | 16.17 | 19.80 | 21.21 | 22.61 | 25.83 | 5.90 % | 0.059 | 0.941 |
| PLV-Cf | 277 | 22.96 | 1.95 | 18.08 | 21.43 | 23.36 | 24.47 | 25.95 | 0.00 % | 0.000 | 1.000 |
| PLV-Df | 54 | 23.86 | 1.79 | 18.58 | 22.66 | 24.33 | 25.39 | 25.99 | 0.00 % | 0.000 | 1.000 |
| Males | |||||||||||
| PLV-Am | 12 | 20.32 | 1.61 | 17.69 | 19.58 | 20.27 | 21.48 | 22.80 | 9.00 % | 0.090 | 0.910 |
| PLV-Bm | 151 | 21.17 | 2.13 | 17.62 | 19.48 | 20.85 | 22.68 | 25.43 | 2.60 % | 0.026 | 0.974 |
| PLV-Cm | 308 | 22.49 | 2.11 | 18.10 | 20.86 | 22.63 | 24.22 | 25.43 | 0.00 % | 0.000 | 1.000 |
| PLV-Dm | 87 | 23.37 | 1.85 | 18.67 | 22.29 | 23.61 | 24.94 | 25.93 | 0.00 % | 0.000 | 1.000 |
n-tds indicates the tooth development stages for the subgroup (PLV-A etc.) as distinct from N which refers to the full sample of 1000 females and 1000 males. The numbers in italics indicate a probability of being under or over 18-years as 0.000 [0%] and 1.000 [100% certainty]