Most people have four wisdom teeth - two in the upper jaw and two in the lower jaw. It is not uncommon for these teeth to become impacted. An impacted tooth is one that has not grown through the gum into the mouth or has grown only part way through, and is in an abnormal position. This is an unhealthy situation and the tooth should be removed for a number of reasons.
Other impacted or un-erupted teeth
Often young people when growing, do not have enough space for all teeth to erupt into their mouths. If these teeth are essential for ideal bite and function, the surgical exposure of these teeth may be necessary.