Table 11. Prevalence of IMTM follicular spaces and its association with related influence factors.
| Variables | prevalence of IMTM follicular spaces | Total | χ2 | p | ||
|---|---|---|---|---|---|---|
| <2mm (N=974) | 2mm–3mm (N=14) | >3mm (N=19) | (N=1007) | |||
| Gender | ||||||
| Male | 450 | 7 | 9 | 466 | 0.089 | 0.956 |
| (96.6%) | (1.5%) | (1.9%) | (100.0%) | |||
| Female | 524 | 7 | 10 | 541 | ||
| (96.9%) | (1.3%) | (1.8%) | (100.0%) | |||
| Age | ||||||
| 18–25 | 220 | 2 | 3 | 225 | N/A† | 0.626† |
| (97.8%) | (0.9%) | (1.3%) | (100.0%) | |||
| 26–35 | 287 | 6 | 9 | 302 | ||
| (95.0%) | (2.0%) | (3.0%) | (100.0%) | |||
| 36–45 | 239 | 5 | 5 | 249 | ||
| (96.0%) | (2.0%) | (2.0%) | (100.0%) | |||
| 46–55 | 117 | 0 | 1 | 118 | ||
| (99.2%) | (0.0%) | (0.8%) | (100.0%) | |||
| ≥56 | 111 | 1 | 1 | 113 | ||
| (98.2%) | (0.9%) | (0.9%) | (100.0%) | |||
| Winter’s classification | ||||||
| Vertical impaction | 362 | 6 | 8 | 376 | N/A† | 0.000***† |
| (96.3%) | (1.6%) | (2.1%) | (100.0%) | |||
| Mesioangular impaction | 289 | 3 | 1 | 293 | ||
| (98.6%) | (1.0%) | (0.3%) | (100.0%) | |||
| Horizontal impaction | 237 | 1 | 3 | 241 | ||
| (98.3%) | (0.4%) | (1.2%) | (100.0%) | |||
| Distoangular impaction | 56 | 3 | 6 | 65 | ||
| (86.2%) | (4.6%) | (9.2%) | (100.0%) | |||
| Other types of impaction | 30 | 1 | 1 | 32 | ||
| (93.8%) | (3.1%) | (3.1%) | (100.0%) | |||
| Pell & Gregory’s classification (Ramus) | ||||||
| Class I | 373 | 2 | 4 | 379 | N/A† | 0.130† |
| (98.4%) | (0.5%) | (1.1%) | (100.0%) | |||
| Class II | 429 | 10 | 11 | 450 | ||
| (95.3%) | (2.2%) | (2.4%) | (100.0%) | |||
| Class III | 172 | 2 | 4 | 178 | ||
| (96.6%) | (1.1%) | (2.2%) | (100.0%) | |||
| Pell & Gregory’s classification (Occlusal) | ||||||
| Position A | 506 | 9 | 14 | 529 | N/A† | 0.216† |
| (95.7%) | (1.7%) | (2.6%) | (100.0%) | |||
| Position B | 326 | 5 | 3 | 334 | ||
| (97.6%) | (1.5%) | (0.9%) | (100.0%) | |||
| Position C | 142 | 0 | 2 | 144 | ||
| (98.6%) | (0.0%) | (1.4%) | (100.0%) | |||
| Contact status between IMTM and MSM | ||||||
| No contact | 149 | 4 | 2 | 155 | N/A† | 0.524† |
| (96.1%) | (2.6%) | (1.3%) | (100.0%) | |||
| Point contact | 35 | 0 | 1 | 36 | ||
| (97.2%) | (0.0%) | (2.8%) | (100.0%) | |||
| Surface-to-surface contact | 790 | 10 | 16 | 816 | ||
| (96.8%) | (1.2%) | (2.0%) | (100.0%) | |||
| MSM distal alveolar bone condition | ||||||
| Compressive resorption | 890 | 14 | 18 | 922 | N/A† | 0.775† |
| (96.5%) | (1.5%) | (2.0%) | (100.0%) | |||
| Inflammatory resorption | 84 | 0 | 1 | 85 | ||
| (98.8%) | (0.0%) | (1.2%) | (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).