The human body has 32 teeth, lets just say that no one in the world has any teeth missing. In 2011 the population of the world was 6,973,738,433, so it is probably around 7,000,836,291 or so in 2013, we'll times that by 32 which gives us the amount of teeth on Earth, approximately 224,026,761,312. Since you are probably going to need more than that to eat our world, we'll times that by 2 which gives us the amount of how much teeth you probably have, 448,053,522,624 teeth.