Histological and Histomorphometric Evaluation of Anterior Part of Rats Tongue Exposed to Passive Cigarette Smoking

Tobacco causes multiple human malignancies including cancers of the lung, oral cavity, pharynx, stomach, liver and cervix. The current study aimed to investigate the effect of passive cigarette smoke on histological feature of anterior part of tongue and filiform and fungiform lingual papillae. Twelve male albino rats were divided in to two groups. One served as control while the other exposed to passive cigarette smoke for 60 days. Tongues specimens underwent histopathological and histomorphometric analysis. The tongue of passive smoking group represented pleomorphic filiform papillae with excessive keratin formation, marked disappearance of secondary papillae with flattening of the basement membrane. The fungiform papillae were smaller in size having thin keratin layer and some of them had degenerated taste bud. The serous acini of the anterior part showed mild vacuolization and inflammatory infiltration in the connective tissue stroma. The ventral surface showed decreased epithelial thickness, basement membrane irregularity and thinning of the keratin layer. Histomorphometric analysis showed decreased diameter of the filiform in response to passive smoking while its length differ according to its location; papillae at tip had normal length, at dorsal surface became elongated while those near the root had a decreased length. In conclusion, passive smoking had a deleterious effects on the histological structure of anterior part of tongue. In addition, it affected the morphology of filiform and fungiform lingual papillae.