Table 2 Univariable analysis of crude association between dental fluorosis and each explanatory variable
Variable | Cases n (%)† | Controls n (%)† | Univariable model‡ | ||
|---|---|---|---|---|---|
PR | 95% CI | P-value | |||
Total | 132 | 157 | |||
Main exposure variable | |||||
Time-averaged fluoride concentration (ppm)* | |||||
< 0.7 | 7 (23.3) | 23 (76.7) | Reference | ||
0.7–1.49 | 23 (37.7) | 38 (62.3) | 1.62 | 0.78, 3.34 | 0.195 |
≥ 1.5 | 127 (64.1) | 71 (35.9) | 2.75 | 1.42, 5.31 | 0.003 |
Other explanatory variables | |||||
Sex | |||||
Female | 74 (54.4) | 62 (45.6) | Reference | ||
Male | 83 (54.3) | 70 (45.7) | 1.0 | 0.81, 1.23 | 0.978 |
Age (year) | |||||
< 8 | 48 (48.5) | 51 (51.5) | Reference | ||
≥ 8 | 109 (57.4) | 81 (42.6) | 1.18 | 0.93, 1.50 | 0.165 |
Caregiver’s education | |||||
≥ Secondary school | 28 (54.9) | 23 (45.1) | Reference | ||
< Secondary school | 84 (60.0) | 56 (40.0) | 1.09 | 0.82, 1.45 | 0.540 |
Sufficiency of family income per month [≥ 26,025 THB]** | |||||
Sufficient | 6 (75.0) | 2 (25.0) | Reference | ||
Insufficient | 112 (58.0) | 81 (42.0) | 0.77 | 0.51, 1.18 | 0.230 |
Breastfeeding | |||||
Yes | 107 (56.9) | 81 (43.1) | Reference | ||
No | 20 (83.3) | 4 (16.7) | 1.46 | 1.18, 1.82 | 0.001 |
Brushing frequency before 2 years old | |||||
No brushing | 11 (50.0) | 11 (50.0) | Reference | ||
Once a day | 78 (65.0) | 42 (35.0) | 1.30 | 0.84, 2.02 | 0.241 |
≥ 2 times a day | 39 (53.4) | 34 (46.6) | 1.07 | 0.67, 1.71 | 0.783 |
Brushing frequency at ≥ 2 years old | |||||
Once a day | 35 (55.6) | 28 (44.4) | Reference | ||
≥ 2 times a day | 97 (60.2) | 64 (39.8) | 1.08 | 0.84, 1.40 | 0.532 |
Fluoride toothpaste use | |||||
No | 8 (66.7) | 4 (33.3) | Reference | ||
Yes | 117 (58.8) | 82 (41.2) | 0.88 | 0.58, 1.34 | 0.555 |
Toothpaste size | |||||
Pea-sized | 54 (50.5) | 53 (49.5) | Reference | ||
> Pea-sized | 74 (65.5) | 39 (34.5) | 1.30 | 1.03, 1.63 | 0.027 |
Fluoride supplement§ | |||||
No | 95 (59.4) | 65 (40.6) | Reference | ||
Yes | 33 (54.1) | 28 (45.9) | 0.91 | 0.70, 1.19 | 0.491 |