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Effects of Tobacco on the Ear

The origin of the cholesteatoma matrix remains controversial although most investigators favor the hypothesis of epidermal migration from a perforated tympanic membrane. The metaplasia theory of the histogenesis of cholesteatoma is rarely considered relevant today. This study demonstrated that following repetitive exposures to a potent irritant such as tobacco tar, stratified squamous epithelial metaplasia can occur in the aural bulla of the cat. The investigation included six cats with indwelling polyethylene tubes surgically inserted into both aural bullae. In each cat the left bullae served as a control and 0.2 ml of tobacco tar from a cigarette smoking machine was instilled at weekly intervals into the right bullae. The animals were sacrificed in sequence at weekly intervals one week following the instillations so that the first animal had two weeks exposure and the sixth, seven weeks. In addition to metaplastic stratified squamous epihelium, goblet cell metaplasia was also seen.