Background: Chronic alcohol consumption is a major risk factor for oral and pharyngeal cancer. Besides other mechanisms a toxic effect of ethanol and/or its metabolite acetaldehyde on the oral mucosa and a resulting increased cell regeneration seem to play an important role in tumor promotion.
Methods: In the present study the effect of chronic ethanol consumption on the morphology of the oral mucosa of 20 male wistar rats that had been fed nutritionally adequate liquid diets containing 36% of total calories either as ethanol or isocaloric carbohydrates for six months was investigated.
Results: Morphometric analysis showed that in the ethanol rats, the size of the basal cell nuclei of the oral mucosa from the floor of the mouth, the edge of the tongue, and the base of the tongue was significantly increased (p < 0.001). The size of the basal cell layer in these rats was increased, and the stratification of the cells was altered. Mean epithelial thickness of the mucosa from the floor of the mouth was significantly reduced in the ethanol rats (p < 0.01).
Conclusions: In conclusion, our results indicate that chronic ethanol consumption causes oral mucosa atrophy associated with hyperregeneration, which may result in an enhanced susceptibility of the mucosal epithelium to chemical carcinogens.