Wisdom tooth extractions: What is an impacted wisdom tooth?

A "wisdom tooth" is a type of molar. As you probably know, molars are the chewing teeth found furthest toward the rear of the mouth.

Most humans have first, second, and third molars. A "wisdom tooth" is technically a third molar, and these teeth come in behind a person's second molars, in most cases when a person is in their late teens or early twenties. (This assumes that there is enough room for the wisdom tooth and that it is aligned properly.)

What is an "impacted wisdom tooth"?

In dental terms the word "impacted" indicates that a tooth has been unable to fully erupt into its normal position. In the case of an impacted wisdom tooth, the problem might be that there is not enough room in the person's jaw for the tooth, or else the angulation of the wisdom tooth is improper.

Impacted wisdom tooth classifications.

Oral surgeons and dentists use special terminology to describe an impacted wisdom tooth's positioning in the jaw. The most common type of impacted wisdom tooth is one that is impacted mesially. The term "mesial" simply means that the wisdom tooth is angled forward, toward the front of the mouth.

The other types of impactions, in order of frequency of occurrence, are the vertical, horizontal, and distal types.



A wisdom tooth can also be classified as either a soft tissue or bony impaction. (These terms are used in conjunction with the terms mesially, vertically, horizontally, and distally impacted.) A "bony" impaction is one where the wisdom tooth is still fully encased in bone. A "soft tissue" impaction refers to a wisdom tooth whose upper portion has erupted through the bone somewhat, but not yet through the gums.

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Why are some wisdom teeth be impacted?

The reason why a wisdom tooth might be impacted is not an easy question to answer. The primary cause of wisdom tooth impaction is simply that there is inadequate jawbone space behind the person's second molar (the second molar comes in and is already in position some years before the wisdom tooth behind it tries to come into place). Why this lack of space exists is not fully understood, however there does seem to be a correlation between large tooth size, tooth crowding, and impacted wisdom teeth.

It has been suggested that the coarse nature of stone age man's diet produced extensive tooth wear, not just on the chewing surface of the teeth but also on those aspects of a tooth that are in contact with neighboring teeth. The net effect of this wear would be that the collective "length" of the teeth, as a set, is reduced, thus providing enough jawbone space to accommodate the wisdom teeth. In comparison the diet of modern man does not typically cause severe tooth attrition.

It has also been suggested that the coarseness of stone age man's diet, as compared to modern man's much softer diet, probably required greater chewing activity. This activity could have stimulated greater jawbone growth and as a result created more space for wisdom teeth.

The untamed and wild nature of the caveman's world could no doubt create many situations where teeth were broken or even lost. Once a tooth (or a portion of it) is missing the teeth behind it will have a propensity to move forward. This type of shifting would create more jawbone space for wisdom teeth. In comparison, with the advent of dentistry there are relatively few reasons why a tooth would be lost or remain in a state of disrepair.