South African mercenaries in Iraq:

"They were always very nicely turned out, with shirts and trousers pressed - unlike the Brits, who rarely bothered with an iron - but many of them were badly shot up, with fingers missing and scars all over their body. They also had terrible brown-stained teeth. Most had served in the Special Forces in the 1980s, fighting jungle wars in Angola. During a three-month combat tour, they couldn't use toothpaste because the smell of it could warn the Angolan scouts in the close-quarters fighting that dominated the conflict. As a result, all of their teeth were completely rotten. Once, Mark [Britten] was talking to a South African in his fifties when two teeth simply fell out of his mouth onto the table in front of them."

from War PLC by Stephen Armstrong, in which we also learn that Group 4 Securicor is Africa's largest private employer, with 82,000 employees on the continent.