What is an Impacted tooth?

A tooth is called impacted if it does not assume its proper position and function within its normal eruption time.

Lack of space in the jaw is one of the chief causes for impacted teeth. In an attempt to erupt, the tooth ends up in haphazard positions.

Wisdom teeth are considered impacted when they are unable to erupt into their normal functional positions, mainly due to lack of space for their eruption. Approximately 20% of the population has impacted wisdom teeth. Less than 5% of the population has sufficient room to accommodate the wisdom teeth. Of the other permanent teeth in normal individuals, very few are found impacted except the canines.

What are the causes for impaction of wisdom teeth?

It has been found that during the process of evolution, the jaws are progressively becoming smaller in size and the braincase is expanding at the expense of the jaws. This is said to occur because with the passage of time, man is increasingly using his brain whereas the use of the jaws for chewing has been progressively on the decline, as the diet we are having has become refined and soft. Hence the chewing efficiency of the jaws is not put to full use. Masticatory force (force exerted while chewing) has been found to be contributory to jaw growth. Soft diet thus adversely affects jaw growth. An underdeveloped jaw will not be able to accommodate all 32 teeth. This reduces the space for the wisdom teeth, which erupt last, to erupt into place. Evolutionary trends also point to a gradual reduction in the number of teeth, though this may occur only over a considerable period of time.

Another important factor, which predisposes to development of impacted wisdom teeth, is heredity. It has been found that parents who have impacted wisdom teeth are likely to pass on the trait to children. However, this may only be a very small part of the evolutionary design.

Certain disease conditions such as rickets, endocrine dysfunction, anemia, achondroplasia, cleidocranial dysostosis, Treacher Collins syndrome etc. have also found to be associated with impacted teeth. Here, impactions of teeth other than that of the wisdom teeth are also found frequently.

What are the problems associated with impacted wisdom teeth?

Infection is the most common problem encountered associated with impacted teeth. It may range from a localized gum infection to acute, extensive, life-threatening infections involving the head and neck. Localized gum infections tend to recur intermittently when complete eruption of the tooth is not possible. Recurrent infections (which may be subacute and not painful for the patient) will frequently lead to gum disease and decay on adjacent teeth, which can ultimately result in the loss of these teeth in addition to the wisdom teeth.

Sometimes wisdom teeth erupt in abnormal positions and angulations making them non-functional, as they are unable to contact their corresponding opposing wisdom teeth. In such situations, frequent cheek biting or tongue biting can result from the abnormal positioning causing injuries to the cheeks and tongue while chewing. Besides this, the unsupported upper wisdom tooth also starts over-erupting, lengthening out from the supporting gums, thereby leading to food trapping, decay and gum infections in the region.

There are situations when the wisdom teeth do not erupt at all into the mouth. They lie buried within the gum tissue or bone. Often, patients do not experience problems in such situations. There are also instances where wisdom teeth are totally absent in certain individuals.

Symptoms:

  pain or tenderness of the gums (gingiva)
  unpleasant taste when biting down on or near the area
  visible gap where a tooth did not emerge
  bad breath
  redness and swelling of the gums around the impacted tooth
  swollen lymph nodes of the neck (occasionally)
  difficulty opening the mouth (occasionally)
  prolonged headache or jaw ache

Should the Impacted tooth be removed?

Not all impacted wisdom teeth give trouble to the patient. It is only the partially erupted wisdom teeth and the ones leaning on the adjacent normal teeth, which giving the maximum trouble. Trouble can be in the form of infection of the tooth and the gum, pain, swelling, inability to open the mouth and in extreme cases tumor growing on a trapped wisdom tooth. Therefore it is advisable to remove a potentially problematic wisdom tooth much in advance than actually waiting for the problem to occur. Removal of a tooth is much easier in a younger patient; therefore putting of the removal for a much later age is not a good idea.