Abstract Skin, gingiva, and mucous membranes are stratified squamous epithelia that are continuously renewing systems in a steady state. 1 Under normal conditions, mitotic reproduction, differentiation, and desquamation are balanced in order to achieve the steady state. The end product of normal keratinization is a completely differentiated horny cell that contains filaments and matrix and is enclosed by a thickened plasma membrane. 2,3 When the epithelium is wounded, the steady state is disrupted and the cells acquire a new activity, that of migration. 4–8 Differentiation is altered, and the production of membrane-coating granules, keratohyalin granules, and a thickened plasma membrane is interrupted. This paper is concerned with the cellular activities and ultrastructural changes that take place in response to an incision wound, the reparative process, and the return of the covering epithelium to the orthokeratotic steady state.