I heard somewhere that European conquerers desecrated the noses of Egyptian statues - for example - the Sphinx, the statue of Cleopatra, in order to remove any trace of African features. And that's why Roman/Greek statues have their noses intact but Egyptian ones don't. I'd always been taught in school that the noses just fell off, so I'm not sure.
Discovery Channel did a special on the Sphinx and it dispelled the myth of Napoleon's soldiers knocking the nose off. The real culprit was a Muslim fanatic in the 14th century who was angry that Egyptians were worshipping a statue to bring good harvests. From the book "Frommer's Egypt"
"Napoleon is rumored to be behind the act of destroying it; however, the Frenchman is innocent, as the guilt falls entirely on a 14th-century fanatic named Muhammed Saim Al Dahr, who was angered by peasants making offerings to the Sphinx in hopes of a good harvest. Al Dahr paid heavily for his vandalism; he was later hanged."