If left untreated, they can abscess or form a cyst later in life. Plus, the wisdom teeth, due to pressure, can negatively affect the second molar (in front of them). I have seen patients loose both the second molar and the wisdom tooth.
Ideally, wisdom teeth should be removed as a teenager. At this age, the roots aren't fully formed, making the extraction less traumatic, hence less painful and easier recovery. I often give the comparison of taking down a tree as a sappling as opposed to a thirty year old mature tree. The other advantage to early removal of the wisdom teeth is less chance of nerve damage. (On lower wisdom teeth, the nerve that supplies sensation to your lower lip lies under these teeth).
Normally, most patients have four wisdom teeth and it's best to get them all removed at once – one recovery. This is usually done under IV sedation by a dental anesthesiologist.
Dr. Ian Gray and Staff