Table 1.
Frequency distribution of age, sex, maternal education, oral hygiene by presence, and severity of molar–incisor hypomineralization
| Variables | MIH presence | MIH severitya | ||||
|---|---|---|---|---|---|---|
| No (n = 443), n (%) | Yes (n = 243), n (%) | P | Codes 0–1 (n = 488), n (%) | Codes 2–3 (n = 198), n (%) | P | |
| Age, mean±SD | 8.9±1.51 | 9.2±1.40 | 0.032 | 8.9±1.50 | 9.3±1.41 | 0.002 |
| Sex | ||||||
| Females | 245 (67.1) | 120 (32.9) | 0.137 | 265 (72.6) | 100 (27.4) | 0.366 |
| Male | 198 (61.7) | 123 (38.3) | 223 (69.5) | 98 (30.5) | ||
| Maternal education | ||||||
| No formal education or elementary school | 39 (10.5) | 28 (89.5) | 0.500b | 40 (59.7) | 27 (40.3) | 0.076 |
| Elementary school or some middle school | 24 (58.2) | 245 (41.8) | 191 (71.0) | 78 (29.0) | ||
| Middle school or higher educational attainment | 230 (65.7) | 120 (34.3) | 257 (73.4) | 93 (27.6) | ||
| Toothbrushing frequency (/day) | ||||||
| ≤1 | 89 (57.4) | 66 (42.6) | 0.034 | 100 (64.5) | 55 (35.5) | 0.039 |
| >1 | 354 (66.7) | 177 (33.3) | 388 (73.0) | 143 (26.9) | ||
| Dental biofilm | ||||||
| OHI <2 | 328 (64.3) | 182 (35.7) | 0.806 | 356 (69.8) | 154 (30.2) | 0.190 |
| OHI ≥2 | 115 (65.3) | 61 (34.7) | 132 (75.0) | 44 (25.0) | ||
aMIH severity code: 0 = No MIH, 1 = Mild, 2 = Moderate, 3 = severe, bChi-square test P value of maternal education categories. MIH = Molar–incisor hypomineralization, SD = Standard deviation, OHI = Oral Hygiene Index