Table 7. Severity of IMTM caries and its association with related influence factors.
| Variables | Severity of IMTM caries | Total | χ2 | p | |||
|---|---|---|---|---|---|---|---|
| No | Mild | Moderate | Severe | (N=1007) | |||
| (N=939) | (N=52) | (N=9) | (N=7) | ||||
| Gender | |||||||
| Male | 430 | 25 | 5 | 6 | 466 | N/A† | 0.188† |
| (92.3%) | (5.4%) | (1.1%) | (1.3%) | (100.0%) | |||
| Female | 509 | 27 | 4 | 1 | 541 | ||
| (94.1%) | (5.0%) | (0.7%) | (0.2%) | (100.0%) | |||
| Age | |||||||
| 18–25 | 220 | 5 | 0 | 0 | 225 | N/A† | 0.007**† |
| (97.8%) | (2.2%) | (0.0%) | (0.0%) | (100.0%) | |||
| 26–35 | 279 | 19 | 3 | 1 | 302 | ||
| (92.4%) | (6.3%) | (1.0%) | (0.3%) | (100.0%) | |||
| 36–45 | 234 | 12 | 2 | 1 | 249 | ||
| (94.0%) | (4.8%) | (0.8%) | (0.4%) | (100.0%) | |||
| 46–55 | 109 | 5 | 2 | 2 | 118 | ||
| (92.4%) | (4.2%) | (1.7%) | (1.7%) | (100.0%) | |||
| ≥56 | 97 | 11 | 2 | 3 | 113 | ||
| (85.8%) | (9.7%) | (1.8%) | (2.7%) | (100.0%) | |||
| Winter’s classification | |||||||
| Vertical impaction | 345 | 24 | 4 | 3 | 376 | N/A† | 0.461† |
| (91.8%) | (6.4%) | (1.1%) | (0.8%) | (100.0%) | |||
| Mesioangular impaction | 270 | 18 | 2 | 3 | 293 | ||
| (92.2%) | (6.1%) | (0.7%) | (1.0%) | (100.0%) | |||
| Horizontal impaction | 232 | 7 | 1 | 1 | 241 | ||
| (96.3%) | (2.9%) | (0.4%) | (0.4%) | (100.0%) | |||
| Distoangular impaction | 60 | 3 | 2 | 0 | 65 | ||
| (92.3%) | (4.6%) | (3.1%) | (0.0%) | (100.0%) | |||
| Other types of impaction | 32 | 0 | 0 | 0 | 32 | ||
| (100.0%) | (0.0%) | (0.0%) | (0.0%) | (100.0%) | |||
| Pell & Gregory’s classification (Ramus) | |||||||
| Class I | 336 | 33 | 7 | 3 | 379 | N/A† | 0.000***† |
| (88.7%) | (8.7%) | (1.8%) | (0.8%) | (100.0%) | |||
| Class II | 428 | 17 | 2 | 3 | 450 | ||
| (95.1%) | (3.8%) | (0.4%) | (0.7%) | (100.0%) | |||
| Class III | 175 | 2 | 0 | 1 | 178 | ||
| (98.3%) | (1.1%) | (0.0%) | (0.6%) | (100.0%) | |||
| Pell & Gregory’s classification (Occlusal) | |||||||
| Position A | 478 | 39 | 8 | 4 | 529 | N/A† | 0.004**† |
| (90.4%) | (7.4%) | (1.5%) | (0.8%) | (100.0%) | |||
| Position B | 322 | 10 | 1 | 1 | 334 | ||
| (96.4%) | (3.0%) | (0.3%) | (0.3%) | (100.0%) | |||
| Position C | 139 | 3 | 0 | 2 | 144 | ||
| (96.5%) | (2.1%) | (0.0%) | (1.4%) | (100.0%) | |||
| Contact status between IMTM and MSM | |||||||
| No contact | 148 | 4 | 0 | 3 | 155 | N/A† | 0.207† |
| (95.5%) | (2.6%) | (0.0%) | (1.9%) | (100.0%) | |||
| Point contact | 35 | 1 | 0 | 0 | 36 | ||
| (97.2%) | (2.8%) | (0.0%) | (0.0%) | (100.0%) | |||
| Surface-to-surface contact | 756 | 47 | 9 | 4 | 816 | ||
| (92.6%) | (5.8%) | (1.1%) | (0.5%) | (100.0%) | |||
| MSM distal alveolar bone condition | |||||||
| Compressive resorption | 866 | 43 | 7 | 6 | 922 | N/A† | 0.026*† |
| (93.9%) | (4.7%) | (0.8%) | (0.7%) | (100.0%) | |||
| Inflammatory resorption | 73 | 9 | 2 | 1 | 85 | ||
| (85.9%) | (10.6%) | (2.4%) | (1.2%) | (100.0%) | |||
*p<0.05, **p<0.01, ***p<0.001
†p-values were calculated using Fisher’s exact test with Monte Carlo simulation (10,000 replications), as the chi-squared test was not applicable due to violations of its assumptions (≥20% of cells had expected counts of 1 < T < 5).