Why are they called “wisdom teeth”? Because they appear so much later than other teeth, usually coming in between 17-25 – when one is (supposedly) wiser.

This third set of molars, which appear in the very back of the mouth beyond the other two sets of molars, are considered vestigial, a holdover from a time when our ancestors needed to grind down plant tissue for food. Since our diet has changed, we don’t really need wisdom teeth anymore, but most of us still have them. (Though up to 35% of people are missing at least one wisdom tooth, and some people have none at all.)

These days, wisdom teeth may be nothing more than a pain to people who do have them, as up to 85% of people with wisdom teeth will eventually need them removed. Dentists recommend they be extracted because if left alone, they can cause some big problems, including the following.

When They Don’t Come In: Impacted Wisdom Teeth

Impacted teeth are fully or partially stuck under the gum line, unable to emerge into the mouth on their own. Partially impacted wisdom teeth can lead to significant infections as food and germs become trapped under the gums.  The most common teeth to be impacted are the wisdom teeth, due to their position in the back of the mouth. An impacted tooth is a problem because it can lead to significant pain, swelling, and even infection if left untreated.

A dentist or orthodontist can see where your wisdom teeth are by taking X-rays, which show how impacted they are and give an idea of how difficult an extraction will be. Depending on positioning, some are easier to extract than others.

 When They Come in Wrong: Angled Wisdom Teeth

Not all wisdom teeth are impacted. The problem is that for many people, even if the wisdom teeth do come in on their own, there’s simply not enough room in the jaw to accommodate them. That can lead to problems.

Wisdom teeth that are not impacted may break through the gum line and start to come in but at an angle, pointing in or out of the mouth, towards the second molar or away from it, even completely horizontal. This misalignment means the bite will be off and the wisdom teeth won’t be functional for biting and chewing. It can also lead to damage of the jawbone, nerves, and neighboring teeth.

When They Push Other Teeth Forward: Relapse

Another issue is “relapse,” where teeth that have already been straightened are pushed out of place by wisdom teeth erupting and putting forward pressure on the rest of the teeth. Remember that wisdom teeth are the last to come in, and they may not come in until years after braces and other orthodontic treatment have been completed.

Some dentists and orthodontists believe this is a problem, while others say that it isn’t, since teeth tend to move towards the front of the mouth anyway.

Wisdom Teeth: To Keep or Remove?

If your wisdom teeth are not impacted, are coming in fine on their own, and there’s space in your mouth to accommodate them, then your dentist or orthodontist may not recommend they be removed. If they are recommended for extraction, now you understand why. Although extraction might be uncomfortable at the time, it can save a lot of pain and problems later. Talk to your dentist or orthodontist if you have any concerns about your wisdom teeth and make a plan that’s best for you.