| from smoking | 5 | cause |
| from drinks | 4 | other |
| from the food | 3 | other |
| enamel → be → stained | 11 |
| enamel → become → stained | 4 |
| enamel → can → stain | 3 |
| negative | neutral | positive |
| 0.546 | 0.432 | 0.022 |
| Raw frequency | 18 |
| Normalized frequency | 0.488 |
| Modifier score | 0.500 |
| Perplexity | 178.385 |