Different Patterns of Tooth Wear
9.20.16 in General
Different Patterns Of Tooth Wear, And Their Implications
Well, we know that tooth wear is a very common finding in humans, and that it represents loss of the hardest substance in the body. But what do we know about specific patterns of tooth wear? Do they occur, and do they mean anything of significance? Let’s talk about that.
Statistically the most common wear of teeth that we see is a flattening of the incisal edges of front teeth. Embryologically, front teeth are formed with three lobes that create 3 little “bumps” on the edges of front teeth. Take a look at newly erupted adult front teeth on any 6-7 year old, and you will see these bumps. Yet over time, we wear these edges to a smooth flat edge. This action is called attrition and represents the rubbing together of the two enamel surfaces. As this continues throughout life, we wear right through the enamel and into the second layer of tooth, known as dentin. Dentin is yellowish, and we can often see a yellow center on the edges of worn teeth. Dentin is also 7 times softer than enamel, and therefore, will wear at a faster rate. It will also be more prone to decay and sensitivity, than enamel. Once we wear the edges of our front teeth, which guide our bite and protect the back teeth from forces; we start to be able to rub on our back teeth. This causes attrition of back teeth and more loss of enamel.
Another common pattern of tooth wear is caused by an action called abfraction. The reality is that teeth can bend, with certain forces. Our teeth were meant to sustain very high forces in a direction down their long axis. But, when we hit on teeth with anything but straight up and down forces (ie. lateral forces), we bend the tooth at its neck. This causes a loss of enamel rods at the gumline and creates a little “notched out” area. This can have a few consequences. First, we are damaging tooth by virtue of the lateral forces, potentially causing pain, looseness and cracks. Secondly, we create this notch at the neck of the tooth. This “cave”, if you will, harbors bacteria, is created in dentin, which we know is more sensitive, and serves as the beginning of toppling the tooth in a fracture, much like when we create a notch to cut down a tree.
Unless you are using power tools on your teeth, the only thing we use that is hard enough to wear our teeth is an opposing tooth. WE DO NOT EAT ANYTHING HARD ENOUGH TO WEAR OUR TEETH! The mechanical causes of tooth wear are from teeth wearing teeth.
There are however some chemical causes of wear. This is called erosion, and most commonly is seen when teeth become exposed to some form of acid. This literally dissolves the enamel and dentin.
Sources of acid that dissolve teeth may be, stomach acid in someone who may be bulimic or even has Gastro-Esophageal Reflux Disease (GERD). Certain acidic fruits, especially when kept in the mouth for a long period may cause erosion. Examples would be people who suck on lemons or limes over a long period of time. This is known as fruit-mulling. But, in our American diets, by far, the most common source of destructive acid erosion on our teeth is from the consumption of carbonated soft drinks. Soda contains carbonic and phosphoric acid and they are known potent “eroders” of enamel.
The pattern often associated with chemical wear on teeth is that of wear that eliminates enamel into the yellow dentin, but seen on the sides or back surfaces of teeth. This form of wear is often only detectable on a dental examination, but creates an equally damaging scenario for our teeth.
So, what you may ask can be done about this tooth wear? That’s a great question, and one we will tackle in our next blog. So, stay tuned in and keep smiling. Dr. W.