Wisdom teeth (Third Molar)
Third molars are the last teeth in our oral cavity to erupt, They are more popularly known as wisdom teeth as they erupt after the age of 18 yrs, so they are referred to as the wisdom teeth as people consider it the age a person becomes more mature mentally.
We cannot see the 3rd molars in all the people in some people the teeth erupt and in some they are buried under the soft tissue.
Research: Scientists who are doing research are saying that the dental arches in the humans are shrinking and as a result the 3rd molars are being discarded as the humans are evolving with nature, we can notice that the size of our teeth in oral cavity have not changed, still some of us do not have room for the 3rd molar so we can see that they are not formed as a part of evolutionary process .
But we cannot totally forget about them if they do not appear in pour mouth, they sometimes lie unerupted under the tissue, which can cause infection in the oral cavity and will have to be removed through surgery, So my advice is that if you are above 25yrs and your wisdom teeth have not erupted then you should have a check on them every few years.
In case of Infection: As you can see in the above picture sometimes the 3rd molars grow sideways(impaction) in many patients which makes them to rub against the adjacent teeth roots and causes trauma & infection to the adjacent tooth as well and causes excruciating pain in the mouth, so in these cases they are best removed to protect the other tooth as well. So it is best to keep a regular check with X-ray, and should not be neglected if pain is felt around that area.
Vestigial tooth: These 3rd molars are termed as vestigial teeth as they are of no particular use in our oral cavity as they are in a corner of our mouth and food cannot reach to those corners, so they are termed vestigial