Link to original: http://sarasvati.sanguinarius.org/teeth.htm
In just the last few weeks I have noticed numerous questions about fangs; Do we have them? Do they grow? Are they sharp? Do we attack people with them? In light of this, I figured it would be easy and quick to put this together. Hominid teeth, what they do and what they are for. Because, well, if you have a set of long n' pointies... look to your DNA, not Dracula.
First of all, long pointy canines on a wholly human face are a more recent addition to vampire lore. There are some old myths which give vampire-like beings fangs, sometimes up to seven of them, but of these types they are also usually more animalistic in appearance. The old myths never say that the fangs were used to pierce the neck and drain the blood, some don't even say what they were for, just that they were there. With all of this, though, there are a greater majority of myths without large fanged fiend. Most vampires of mythology resembled people, or had human heads... sans fangs. So why has popular culture latched on so strongly to the idea of those fangs? What makes them so special in peoples minds that a vampire without fangs isn't even a vampire, or at least not one of worry? Perhaps it is because we see these large canines on those predators that most people regard with the most fear and awe: tigers, cougars, wolves, and snakes, and then draw the parallel. Who knows?
The truth is, though, that the teeth most associated with the vampire, were never intended for what popular fiction has made them. Canines are holding teeth, not piercing. Ever notice how the canines of any animal curve backwards, toward the back of their mouth? Its for grip. Think of it this way, take a bar of soap and try to pick it up with your fingers curled out... doesn't work, does it? But, if you curl them back toward you, the soap can't "escape" your hand. Canines in any species are like that. Also, think about what would happen if those canines were long and sharp as a vampires are thought to be, you would often be visiting the doctor to have lacerations of your lips and gums repaired. Just think of how often your lips and tongue move against them in a day? The tips would be quickly broken off as well. Not even a dog or cat's canines are truly sharp, but rounded (cat's teeth seem so sharp due to the relative size of them... look at a cougar's canines and you'll see what I mean). Which is another point to bring up... if you have ever had a dog or cat lunge and attack you, you would notice they put their canines on the far side of what they are trying to bite, and actually bite down with the back teeth, where the jaw can place more pressure, but you can't pull your arm out of their mouth strait forward very easily. Canines are for holding food and not allowing it to escape, but not for piercing necessarily. Also, another thing to keep in mind is that the range of size, length, strength, even number of teeth in the human population is extremely variable. A sanguinarian may not have a set of fangs, but his or her next door neighbor might, even if they are not a sanguin themself.
Piercing and cutting are more the jobs of the incisors (your front teeth). In carnivores, herbivores, and omnivores these teeth are made for cutting. After all, when you bite into an apple, which teeth contact the apple first? Which shear off that piece of apple so you can chew it? Chewing is the job of the molars and pre-molars (the back teeth). They grind the food and mix it with saliva so it can be swallowed. They also do some cutting in the process, especially the pre-molars (those right behind your canines).
Now, I know I am starting to bore, so I'll stop. But, try something next time you get the chance...try to bite or chew with your canines. I bet you find it very difficult. They simply aren't made for the job. Sure, you can bite a pop can and get some holes with them, but drinking out of those holes is another story.