Ask the Dentist: Few of us bite necks but our 'fangs' are still there for a good reason
For Lucy Stock, dentist at Gentle Dental Care in Belfast, Halloween serves as a reminder of why we need our pointy canines
“SHE rounded on me with such ferocity that for a moment I didn't recognise her. A flash of fangs, a dark gleam in her blacker-than-night eyes. It was the most vampiric I'd ever seen her.” A quote from Melika Dannese Lux's book, Corcitura.
This is how we typically image vampires, with their long piercing fangs which undoubtably help with killing their prey. But why do we mere mortal humans have pointy canine teeth at all?
Early hominids probably used their canines as a weapon for taking prey, preventing others from taking their prey and competing for mates. Over millions of years, possibly in response to dietary changes, the teeth became smaller.
Now we have six front teeth made up of four flatter spade-shaped incisors and two pointy canines that are situated at the 'corners' of the dental arches. The function of incisor teeth is to grip and tear food.
But this is not the only reason that canine teeth have a pointy shape. The body is much more sophisticatedly designed than that. The teeth, facial muscles, jaw joints, skull bones, nerves and ligaments fit together perfectly. Every notch, flat surface, curve, bump and hole in each element is there for a reason.
Each “material” – ie bone, nerve, muscle, cartilage etc – has been chosen to do a specific job. The skull, you could say, is the most perfectly designed machine for its end functions.
Your teeth not only bite together, like a crocodile snap, they also slide around. You have left and right slides and forward slides. There are two jaw joints on each side of your head that are joined together by the lower jaw. No other joints in the body are joined in this manner. This means that when the jaws close and teeth come together, the forces have to be evenly distributed so that nothing breaks.
Each tooth has cusps (the bumps) that fit into their partner tooth in the opposite jaw and they are a certain shape to allow the jaw to slide left, right and forward. The eye teeth are pointy to allow other teeth to pass them when the jaw is sliding. The canine teeth also have a special protective quality when the jaw slides where on some movements only the canines contact. This is the most balanced position for the facial muscles and joints; it protects all the teeth, joints and muscles from overloading forces which break things or cause pain.
If a tooth was the wrong shape, the canine squarer, it's kind of like a car bonnet closing with a marble stuck to the inner edge preventing the bonnet from shutting properly. This would either make the bonnet buckle, the bonnet hinges wear or the car chassis dent.
Have a fangtastic Halloween!