Wisdom Teeth: What Are They & Why Do We Have Them?

Wisdom Teeth: What Are They & Why Do We Have Them?
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Wisdom Teeth: What Are They & Why Do We Have Them?Clinical Content Reviewed by Dr. Jay Khorsandi, DDS
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Table of Contents

  1. What Are Wisdom Teeth
  2. Why Do We Have Wisdom Teeth
  3. Signs for Wisdom Teeth Removal
  4. Wisdom Teeth Removal
  5. After Third Molars Are Removed
  6. References

The term wisdom teeth is a colloquialism for the third molars because these teeth come in during adolescence or adulthood, while your other 28 teeth come in during childhood.

Although some people do not have wisdom teeth, and others do not experience problems with them, a significant number of adults develop severe oral health issues because of impacted, partially ruptured, or misaligned wisdom teeth. It is common to have these teeth removed.

What Are Wisdom Teeth?

Adult humans have 32 teeth total: 16 on top, and 16 on the bottom. Only 28 of those typically remain in most adults after a certain age because it is common for adolescents and young adults to have their last molars, or wisdom teeth, removed.

Wisdom teeth are the third molars that come in between the ages of 17 and 21. Third molars have received the name wisdom teeth since they come in at a later stage of life. The other 28 adult teeth come in during childhood, as baby teeth are lost, before 10 years old. Few people keep their wisdom teeth because of complications they can cause.

It is possible to keep wisdom teeth when they come in with proper alignment, with enough room to fully rupture. In fact, they can help you chew lots of tougher foods. However, many adult humans have jaws that are too small to accommodate third molars. When they come in, it can lead to impacted teeth, shifting teeth, cracks and cavities, and many other problems.

Why Do We Still Have Wisdom Teeth?

Every year, more than 5 million Americans have their wisdom teeth removed, although dentists continually debate whether these largely preventative surgeries are necessary. A 2012 Cochrane Review, for example, found that removing wisdom teeth in adolescence or early adulthood did nothing to stop crowding or shifting of the other 28 teeth later in life, so many of the cosmetic benefits associated with removing the third molars may not be valid after all. Instead, “watching and waiting” may reduce the number of unnecessary surgeries, which can decrease trauma and infection by 60 percent.

But why do we need this surgery at all? Many researchers believe that humans evolved third molars very early on in our history before the agricultural revolution. These additional teeth helped early humans eat tough, raw plants and get significant nutritional benefits. However, after humans were able to grow seasonal crops, breed plants for less fiber and more nutrition, and cook many foods to soften them, wisdom teeth became unnecessary for healthy eating. While our jaws may have started to shrink, wisdom teeth have not yet disappeared.

Since wisdom teeth are a vestigial organ, they typically do not come in without shifting the other adult teeth out of alignment. Many wisdom teeth can come in crooked or even impacted, which can cause pain, nerve damage, and infection.

In fact, since human jaw shape is changing, some people do not develop full wisdom teeth. While it is assumed that adults have two on top and two on the bottom for four additional molars, an adult may sometimes develop fewer wisdom teeth than that or none at all.

In some instances, wisdom teeth may develop in the gums but not erupt. These teeth can still cause problems and may need to be removed. This is why many people have wisdom teeth removed in adolescence or young adulthood as a precaution.

On average around the world, about 22 percent of adults do not have all their wisdom teeth come in. About 24 percent of adults experience impacted wisdom teeth, which can cause significant health problems.

If your wisdom teeth have surfaced correctly, in a vertical and functional position, and you aren't experiencing pain, cavities, or infection, they typically don't need to be removed.

What Are the Signs That Wisdom Teeth Need to Be Removed?

Signs that your wisdom teeth need to be removed include:

  • Pain and consistent discomfort.
  • Bad breath that does not go away with brushing your teeth.
  • Infection that damages your teeth and gums.
  • Cysts or tumors.
  • Cracks, pain, sensitivity, and cavities in the neighboring teeth.
  • Gum disease, leading to bleeding, inflammation, and other problems.
  • Fever from consistent infections.

Potential problems with wisdom teeth include the following:

  • Food gets trapped because it is difficult to brush teeth that far back in your jaw.
  • Teeth do not have enough room so they are impacted, which can cause damage to surrounding teeth.
  • Third molars do not come in all the way, which can cause pain and inflammation in the gums and jaw.
  • Partially ruptured wisdom teeth can cause openings in the gums that allow bacteria in, which can lead to gingivitis or periodontitis.
  • Other teeth shift or become crowded because the wisdom teeth push them aside as they come in.
  • Cysts form when impacted wisdom teeth cause damage and infection.
  • Persistent infections from poorly aligned wisdom teeth can cause damage to all your other teeth and even to your jaw.

Getting Your Wisdom Teeth Removed

The most common treatment to prevent or stop problems with wisdom teeth is to remove them. If they have come in but are causing issues like persistent infection, nerve damage, cracked teeth, and jaw problems, the first step in stopping these illnesses and injuries is to remove the wisdom teeth. After that, it is important to:

  • Treat underlying gum infections, which could take multiple visits and require root canals or tooth removal.
  • Get a deep cleaning of several teeth or all teeth to remove tartar buildup.
  • Take any prescribed antibiotics.
  • Schedule extra checkups with your dentist, which may not be covered by your health insurance.
  • Add additional steps to your home oral healthcare routine.

Once you have your wisdom teeth removed, your dentist will schedule additional exams to monitor the healing process. This may involve x-rays, especially if you struggled with ongoing problems because of impacted or misaligned wisdom teeth, which caused further oral health damage.

Wisdom tooth removal surgery is an outpatient treatment, and in many cases, it may not even require full sedation. You may be able to have local anesthesia during the process, which takes much less recovery time.

When the anesthesia wears off, you can return home to begin your recovery.

  • Eat limited, soft foods and avoid sipping through straws for up to two weeks.
  • Take pain medication for one to three days after the treatment.
  • Keep gauze in your mouth to prevent bleeding for a day or two.
  • Rinse gently, without swishing, with warm saltwater to prevent infection.
  • Do not smoke or drink alcohol for several days after surgery.

After Third Molars Are Removed

After you have recovered from wisdom teeth surgery, you may wish to pursue orthodontic treatment to realign your 28 remaining adult teeth. This is very common. It can improve your overall oral health since aligned teeth are easier to keep clean and have fewer places where tartar and plaque can build up and lead to infection.

Your dentist may discuss orthodontic options with you, but if you are concerned about the appearance of your smile, you can search out various orthodontic options at your price point.


Wisdom Teeth. MouthHealthy, from the American Dental Association (ADA). Date fetched: June 21, 2021.

10 Million Wisdom Teeth Are Removed Each Year. That Might Be Way Too Many. (February 2015). Vox. Date fetched: June 21, 2021.

Evolution of Human Teeth and Jaws: Implications for Dentistry and Orthodontics. (June 2012). Wiley Online Library. Date fetched: June 21, 2021.

Why Do Humans Have Wisdom Teeth That Need to Be Removed? (April 2019). Discover Magazine. Date fetched: June 21, 2021.

Wisdom Teeth. (August 2019). Better Health Channel. Date fetched: June 21, 2021.

Interventions for Treating Asymptomatic Impacted Wisdom Teeth in Adolescents and Adults. (April 2018). Cochrane Database Systematic Review.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.