Ah, the joys of young adulthood! Perhaps you've just graduated high school, or entered college. You're eighteen, and the bright future spreads out before you. That -- and your aching wisdom tooth.
Wisdom teeth are an issue, usually in young adulthood, because of a trick of evolution. We have the same number of teeth as our troglodyte ancestors, but our jaws have become shorter. As a result, there is frequently not enough room in the jaw for the wisdom teeth to erupt normally. They may either stay completely submerged in the jaw, or may start coming in and get stuck -- wedged against the second molar in front of it. This is respectively a complete or partial impaction of the wisdom tooth.
Most often, the lower wisdom tooth is the one that causes the problem. Typically, it breaks through the gum and gets stuck, half into the mouth, half below the gum. The crown of the tooth is surrounded by a flap of gum tissue. If food gets stuck under this flap, it is almost impossible to clean out. This leads to an infection around the crown of the wisdom tooth -- a pericoronitis.
In young, healthy patients with pericoronitis, the infection is self-limiting -- it lasts a week or two, drains, and heals. However, as long as the tooth remains partially impacted, there is a good chance the pericoronitis will return. One of the dental corollaries of Murphy's Law states that this will always happen on New Year's Eve, or the night before your wedding.
Patients are generally less aware of wisdom teeth when they are totally impacted. There is less chance of infection, and there are usually no other symptoms. Nevertheless, fully impacted teeth are not risk-free. On occasion, cysts and even tumors may form in the sac surrounding the unerupted crown of the tooth. More commonly, the presence of the tooth behind the roots of the second molar causes a deficiency of supporting bone in this location. If the presence of a cyst or gum disease later in life necessitates removal of the wisdom tooth, this can sometimes lead to loss of the second molar as well.
For this reason, some dentists recommend that all impacted wisdom teeth should be removed. The general recommendation is to remove impacted wisdom teeth while the patient is still young, as healing will be more rapid.
Many dentists are somewhat circumspect about this blanket recommendation. While removing impacted wisdom teeth will eliminate some potential problems, the surgery is not totally risk-free. The wisest course is to adapt the treatment to the needs of the individual presenting conditions. If a 70 year old patient presents with no other teeth but a deeply impacted lower wisdom tooth, most dentists would inform the patient of possible complications, caution the patient to return periodically for x-rays of the area, and leave the tooth alone.
However, this is not a common occurrence. Usually it's that high school or college student studying for their final exams. And after a couple of episodes, the patient usually needs little convincing that what the tooth needs is what we in the trade call "cold steel and sunshine".