It seems just about everyone has to have his wisdom teeth extracted. For most, it’s an easy procedure and an easy recovery. But many people don’t understand why we have those third molars to begin with — or if there are alternatives to removal.

We asked Dr. Robert Williams, a clinical associate professor at the University of Maryland Dental School who also practices in Baltimore and Bel Air, Md.

Q: What is the purpose of wisdom teeth and why do so many people have to have them removed?

A: Wisdom teeth (third molars) were necessary eons ago when humans had a coarser diet and larger jaws. With evolution, our jaws have gotten relatively smaller and, in many cases, there isn’t enough room for them to erupt fully or into a favorable position. Often, these teeth will only partially erupt, leaving a flap of tissue over a portion of the crown of the tooth. Food and bacteria get under this flap and cause an infection. Even if the teeth fully erupt, they are so far back in the mouth that it is difficult to keep them and the surrounding gums clean and healthy.

Q: Are there alternatives to removal or a best time to remove them?

A: The only alternative to removal is to leave them alone. There are two different schools of thought regarding the removal of wisdom teeth. One group recommends prophylactic removal prior to the development of any problems, and the other recommends waiting until a problem develops and removing them at that time. Unfortunately for the “wait and see” group, recovery from the surgery is usually quicker and easier for younger patients. Some wisdom teeth should never be removed if there is a high probability of damaging the underlying nerve, or causing an extensive loss of the bone surrounding the tooth.

Q: What are potential complications from removal?

A: The most common complications are the pain and bleeding that accompany the surgical procedure. This can be controlled with medication and pressure applied over the extraction site. If the clot in the socket is lost, an infection can develop resulting in a “dry socket.” These infections are treated with antibiotics. Rarely, damage to the underlying nerve can occur leading to a partial numbness of the chin. Maintaining the mouth in a wide-open position for an extended period of time may result in pain or discomfort in the jaw joint.

Q: If you have impacted wisdom teeth, does that mean you’ll have other problems such as crooked teeth?

A: There is no relationship between the impaction or eruption of wisdom teeth and other orthodontic problems, especially crowding of the lower front teeth. Wisdom teeth tend to erupt in the late teens to early 20s, about the same time that many people experience some crowding of their lower front teeth, but there is no causal relationship between the two events.