Table 2.
Odds ratios (ORs) and 95% confidence intervals (CIs) of nasopharyngeal carcinoma associated with oral health in southern China (2010–2014).
| Variable | Cases (n=2528) |
Controls (n=2596) |
Minimally adjusted OR (95% CI) * |
Fully adjusted OR (95% CI) † |
||
|---|---|---|---|---|---|---|
| No. | % | No. | % | |||
|
Number of teeth lost after age 20 years |
||||||
| None | 1282 | 50.7 | 1268 | 48.8 | 1.0 (ref.) | 1.0 (ref.) |
| 1 – 3 | 701 | 27.7 | 739 | 28.5 | 0.98 (0.86, 1.12) | 0.97 (0.84, 1.11) |
| 4 – 13 | 417 | 16.5 | 453 | 17.5 | 1.01 (0.85, 1.19) | 0.99 (0.83, 1.18) |
| ≥ 14 | 128 | 5.1 | 136 | 5.2 | 1.10 (0.84, 1.45) | 1.00 (0.75, 1.32) |
| P for trend | 0.46 | 0.98 | ||||
|
Age at first tooth loss (years) ‡ |
||||||
| ≥ 50 | 202 | 16.2 | 306 | 23.0 | 1.0 (ref.) | 1.0 (ref.) |
| 40 – 49 | 285 | 22.9 | 352 | 26.5 | 1.12 (0.87, 1.44) | 1.18 (0.91, 1.53) |
| 30 – 39 | 304 | 24.4 | 323 | 24.3 | 1.26 (0.96, 1.64) | 1.23 (0.93, 1.62) |
| 20 – 29 | 297 | 23.8 | 289 | 21.8 | 1.34 (1.00, 1.79) | 1.33 (0.98, 1.79) |
| unknown | 158 | 12.7 | 58 | 4.4 | - | - |
| P for trend | 0.04 | 0.08 | ||||
| Denture wearing | ||||||
| No | 2161 | 85.5 | 2214 | 85.3 | 1.0 (ref.) | 1.0 (ref.) |
| Yes | 367 | 14.5 | 382 | 14.7 | 1.06 (0.90, 1.24) | 1.03 (0.87, 1.21) |
|
Number of filled teeth |
||||||
| None | 2077 | 82.2 | 2223 | 85.6 | 1.0 (ref.) | 1.0 (ref.) |
| 1 – 3 | 352 | 13.9 | 297 | 11.4 | 1.25 (1.06, 1.47) | 1.25 (1.06, 1.49) |
| ≥ 4 | 99 | 3.9 | 76 | 2.9 | 1.39 (1.03, 1.89) | 1.55 (1.13, 2.12) |
| P for trend | 0.003 | 0.002 | ||||
|
Frequency of brushing teeth (times/day) |
||||||
| ≤ 1 | 1696 | 67.1 | 1456 | 56.1 | 1.0 (ref.) | 1.0 (ref.) |
| ≥ 2 | 824 | 32.6 | 1133 | 43.6 | 0.58 (0.52, 0.66) | 0.62 (0.55, 0.70) |
| Irregular | 8 | 0.3 | 7 | 0.3 | - | - |
|
Frequency of oral discomfort while eating |
||||||
| Never or hardly ever | 1678 | 66.4 | 1786 | 68.8 | 1.0 (ref.) | 1.0 (ref.) |
| Occasionally | 613 | 24.3 | 624 | 24.0 | 1.07 (0.94, 1.22) | 1.08 (0.94, 1.23) |
| Often | 206 | 8.1 | 169 | 6.5 | 1.37 (1.10, 1.70) | 1.27 (1.02, 1.59) |
| Unknown | 31 | 1.2 | 17 | 0.7 | - | - |
|
Avoidance of some foods due to oral problems |
||||||
| Never | 1778 | 70.3 | 1794 | 69.1 | 1.0 (ref.) | 1.0 (ref.) |
| Ever | 750 | 29.7 | 802 | 30.9 | 0.98 (0.86, 1.10) | 0.97 (0.85, 1.10) |
Adjusted for sex, age (5-year categories), and residential area (Zhaoqing, Wuzhou, or Guiping/Pingnan).
Adjusted for sex, age, residential area, education level (≤ 6, 7–9, 10–12, or >12 years), current housing type (building, cottage, or boat), current occupation (unemployed, farmer, blue-collar, white-collar, or other/unknown), first-degree family history of nasopharyngeal carcinoma (yes, no, or unknown), cigarette smoking (ever or never), tea drinking (less than daily or daily), and salt-preserved fish consumption in 2000–2002 (yearly or less, monthly, or weekly or more). We excluded 18 subjects due to missing covariate values.
Among 2574 participants who experienced tooth loss after age 20 years.