The natural shedding of the cells of the outer surface of an organ.

In the desquamation of the synechia of the penis, whorls (a cluster of cells or tissue that surround another) of cells form in the membrane and die from the inside of the whorls out, creating hollows. Over a widely variable period of time, the hollows merge to form the preputial space, which then allows the unique mobility of the foreskin. Desquamation, in the form of de-keratinisation, also occurs from the glans after foreskin restoration.

Reference: Wikipedia entry for Desquamation