Foreskin restoration is the process of expanding the skin on the penis to reconstruct an organ similar to the foreskin, which has been removed by circumcision or injury. Foreskin restoration is primarily accomplished by stretching the residual skin of the penis, but surgical methods also exist. Restoration creates a facsimile of the foreskin, but specialized tissues removed during circumcision cannot be reclaimed. Actual regeneration of the foreskin is experimental at this time. Some forms of restoration involve only partial regeneration in instances of a high-cut wherein the circumcisee feels that the circumciser removed too much skin and that there is not enough skin for erections to be comfortable. In the Greco-Roman world intact genitals, including the foreskin, were considered a sign of beauty, civility, and masculinity. In Classical Greek and Roman societies (8th century BC to 6th century AD), exposure of the glans was considered disgusting and improper, and did not conform to the Hellenistic ideal of gymnastic nudity. Men with short foreskins would wear the kynodesme to prevent exposure. As a consequence of this social stigma, an early form of foreskin restoration known as epispasm was practiced among some Jews in Ancient Rome (8th century BC to 5th century AD). Foreskin restoration is of ancient origin and dates back to the reign of the Roman Emperor Tiberius (AD 14-37), when surgical means were taken to lengthen the foreskin of individuals born with either a short foreskin that did not cover the glans completely or a completely exposed glans as a result of circumcision. Again, during World War II some European Jews sought foreskin restoration to avoid Nazi persecution. Non-surgical foreskin restoration, accomplished through tissue expansion, is the more commonly used method. Tissue expansion has long been known to stimulate mitosis, and research shows that regenerated human tissues have the attributes of the original tissue.