Keywords: Cholesteatoma, temporal bone

Abstract: An experimental study regarding the patterns of epithelial migration in acquired Colesteatoma was performed in the chincilla. A mechanical perforation of the tympanic membrane and the placement of a modified collagen membrane through it induced squamous epithelial cell migration. Migration was observed as occuring through the tympanic membrane perforation, collagen membrane, organized effusion, and granulation tissue. Closure of tympanic membraneperforations occured in some animals as a result of squamous epithelial cell migration in clots of organized effusion. Cholesteatomas were observed in 53,5% of the animals. The importante of these patterns of epithelial migration as related to otites media and the genesis of acquired cholesteatomas will be discussed.