by Eric Misener

Created on: February 23, 2009

Perhaps the reason teenagers these days are smarter than their parents is related to the fact that teens still have their "wisdom" teeth, while it is likely that their parents have had theirs extracted. The term "wisdom teeth" refers to the third set of molars that come into a person's mouth sometime in their late teens or early twenties. Molars are the flat teeth in the back of the mouth that are optimized for chewing or grinding (instead of biting or tearing, like their incisor and bi-cuspid neighbors). It has become almost a right of passage to have one's wisdom teeth extracted after high school graduation, because in a large number of cases, these teeth become "impacted."

"Impacted," in dental parlance, simply means that the tooth has not fully emerged in its proper place from the gum line. Impactions are differentiated by whether they are "bony" or soft-tissue" and by the angle of the tooth in the jaw. A bony impaction means that the tooth is still fully encased in the jaw bone, where a soft-tissue type concerns a case in which the tooth's crown has broken through the jaw-line, but has not fully burst through the gum.

There are four further classifications of impactions which describe how the tooth is angled in the mouth. The most common type is called a "mesial" impaction, which indicates that the tooth is tilted at an angle where the crown is pointed somewhat (but less than completely) toward the front of the mouth. The second most common type of impaction is the "vertical," in which the tooth is standing more or less straight up in the mouth. Third is the "horizontal" impaction, in which the tooth is lying on its side in the jaw, and fourth is the "distal" impaction, in which the crown is angled toward the back of the mouth.

The primary cause of impacted wisdom teeth appears to be a lack of space in the jaw to hold this final set of molars. While it is unknown why this lack space should be so common, some theories concern the eating habits of our distant ancestors. It is possible that in the stone age, human diets were such that more wear was caused on teeth, reducing the volume of each tooth and creating more space, or causing more frequent tooth loss. Because other teeth tend to move up toward the front of the mouth when the tooth in front of it is lost, the wisdom teeth may have been, in a sense, "spares." Another possibility is that this diet required more jaw strength, which, in turn, led to a larger jaw in those distant ancestors. The upshot of these theories is that with modern humans' much softer, more refined diet, the wisdom teeth simply have no place come in.

When wisdom teeth are impacted, a dentist should be consulted to determine if extraction is indicated. Exctraction is done to prevent a myriad of problems that can occur with impacted teeth, the most common of which is the occurrence of "pericoronitis," an infection of the gum tissue. Impacted teeth can create a space in the gum tissue in which plaque can build up, and which can not be cleaned by the individual. Bacteria will grow in these spaces resulting in an infection that can cause gums to swell, an unpleasant odor, and pain. In any case, impacted teeth have little to offer by way of benefit and can be the source of many problems in the future. Therefore, a dentist should be consulted in all cased of tooth impaction so proper measure can be taken to maintain good dental health.

SOURCE: www.animated-teeth.com

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