Impacted and Embedded Teeth
A tooth which has fully formed but has broken through the gum into the mouth is either Impacted or Embedded - they are also known as un-erupted teeth. Instead or erupting through the gum tissue into their correct partition they remain under the surface of either the gum or bone. This can happen for a number of different reasons.
Impacted teeth occur where one tooth is prevented from erupting due to being wedged up against a neighbouring tooth. It is always necessary to extract impacted teeth to prevent further problems.
If a tooth is not breaking through the gum because of being under bone it is classed as being embedded. In the majority of the cases where the tooth is being blocked by the gum it may lack the force necessary to break through the gum, this can often happen without any obvious reason.
There are several categories employed to determine the way in which a tooth can be impacted. Among the easiest variations made, is if a tooth is actually impacted entirely within bone, or if it has broken through the bony cortex and is also partly or entirely covered by the gums: the first kind is called a bony impaction, while the second is called soft-tissue impaction. Each of these categories could be referred to as partial or complete, and either types demand surgical removal techniques of different sophistication to extract them. Wisdom teeth which are located in the lower jaw are by far the most commonly un-erupted.
Exactly why some wisdom teeth tend to be impacted is not a straightforward question to answer. A major reason for wisdom tooth impaction is that there happens to be inadequate space for the jawbone behind the patients second molar tooth, there often appears to be a connection between the size of the tooth, tooth crowding, and experiencing impacted wisdom teeth. Modern day eating habits and a bad diet and can often be a contributory factor.