Table 3. Severity of MSM distal caries and its association with related influence factors.
| Variables | Severity of MSM distal caries | Total | χ2 | p | |||
|---|---|---|---|---|---|---|---|
| No | Mild | Moderate | Severe | (N=1007) | |||
| (N=903) | (N=69) | (N=25) | (N=10) | ||||
| Gender | |||||||
| Male | 410 | 36 | 13 | 7 | 466 | 3.835 | 0.280 |
| (88.0%) | (7.7%) | (2.8%) | (1.5%) | (100.0%) | |||
| Female | 493 | 33 | 12 | 3 | 541 | ||
| (91.1%) | (6.1%) | (2.2%) | (0.6%) | (100.0%) | |||
| Age | |||||||
| 18–25 | 207 | 15 | 3 | 0 | 225 | N/A† | 0.160† |
| (92.0%) | (6.7%) | (1.3%) | (0.0%) | (100.0%) | |||
| 26–35 | 265 | 24 | 11 | 2 | 302 | ||
| (87.7%) | (7.9%) | (3.6%) | (0.7%) | (100.0%) | |||
| 36–45 | 219 | 19 | 8 | 3 | 249 | ||
| (88.0%) | (7.6%) | (3.2%) | (1.2%) | (100.0%) | |||
| 46–55 | 111 | 3 | 1 | 3 | 118 | ||
| (94.1%) | (2.5%) | (0.8%) | (2.5%) | (100.0%) | |||
| ≥56 | 101 | 8 | 2 | 2 | 113 | ||
| (89.4%) | (7.1%) | (1.8%) | (1.8%) | (100.0%) | |||
| Winter’s classification | |||||||
| Vertical impaction | 351 | 21 | 2 | 2 | 376 | N/A† | 0.000***† |
| (93.4%) | (5.6%) | (0.5%) | (0.5%) | (100.0%) | |||
| Mesioangular impaction | 231 | 37 | 18 | 7 | 293 | ||
| (78.8%) | (12.6%) | (6.1%) | (2.4%) | (100.0%) | |||
| Horizontal impaction | 228 | 7 | 5 | 1 | 241 | ||
| (94.6%) | (2.9%) | (2.1%) | (0.4%) | (100.0%) | |||
| Distoangular impaction | 61 | 4 | 0 | 0 | 65 | ||
| (93.8%) | (6.2%) | (0.0%) | (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 | 331 | 32 | 12 | 4 | 379 | N/A† | 0.071† |
| (87.3%) | (8.4%) | (3.2%) | (1.1%) | (100.0%) | |||
| Class II | 401 | 32 | 11 | 6 | 450 | ||
| (89.1%) | (7.1%) | (2.4%) | (1.3%) | (100.0%) | |||
| Class III | 171 | 5 | 2 | 0 | 178 | ||
| (96.1%) | (2.8%) | (1.1%) | (0.0%) | (100.0%) | |||
| Pell & Gregory’s classification (Occlusal) | |||||||
| Position A | 444 | 56 | 20 | 9 | 529 | N/A† | 0.000***† |
| (83.9%) | (10.6%) | (3.8%) | (1.7%) | (100.0%) | |||
| Position B | 317 | 12 | 4 | 1 | 334 | ||
| (94.9%) | (3.6%) | (1.2%) | (0.3%) | (100.0%) | |||
| Position C | 142 | 1 | 1 | 0 | 144 | ||
| (98.6%) | (0.7%) | (0.7%) | (0.0%) | (100.0%) | |||
| Contact status between IMTM and MSM | |||||||
| No contact | 154 | 1 | 0 | 0 | 155 | N/A† | 0.000***† |
| (99.4%) | (0.6%) | (0.0%) | (0.0%) | (100.0%) | |||
| Point contact | 35 | 1 | 0 | 0 | 36 | ||
| (97.2%) | (2.8%) | (0.0%) | (0.0%) | (100.0%) | |||
| Surface-to-surface contact | 714 | 67 | 25 | 10 | 816 | ||
| (87.5%) | (8.2%) | (3.1%) | (1.2%) | (100.0%) | |||
| MSM distal alveolar bone condition | |||||||
| Compressive resorption | 858 | 47 | 12 | 5 | 922 | N/A† | 0.000***† |
| (93.1%) | (5.1%) | (1.3%) | (0.5%) | (100.0%) | |||
| Inflammatory resorption | 45 | 22 | 13 | 5 | 85 | ||
| (52.9%) | (25.9%) | (15.3%) | (5.9%) | (100.0%) | |||
***p<0.001, indicating a statistically significant difference;
†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).