| Type of lesion of the oral mucosa | Number | Percentage (%) |
| Black villous tongue | 32 | 50.79 |
| Neoplastic ulceration | 14 | 22.22 |
| Contact ulceration | 9 | 14.29 |
| Leucoplakia | 4 | 6.36 |
| Lichen planus | 2 | 3.17 |
| Tabacco melanosis | 2 | 3.17 |