Why We Have Wisdom Teeth: Surgery, Pain, and Treatment

  • Reviewed By: Charles Patrick Davis, MD, PhD
    Charles Patrick Davis, MD, PhD

    Charles Patrick Davis, MD, PhD


Reviewed on 11/28/2018

Why Call Them 'Wisdom Teeth?'

We got the name

Your dentist might refer to them as the third molar. But for everyone else, "wisdom teeth" is the name for those protrusions that begin to appear in the back of your mouth around age 18-24. Ever wonder how these teeth developed such a lofty reputation?

Like so many other words, we inherited this one from the ancient Greeks. Those writers actually had three names for these late-blooming teeth, but the one later inherited by English was "sóphronistér." This referred to moderation and the act of teaching--abilities the ancient Greeks believed came later in life. So you acquire wisdom teeth around the same time you start to become wise, at least according to the ancients.

Why Do We Have Wisdom Teeth?

Wisdom teeth once helped our ancestors chew through tough foods like roots and leaves.

Your teeth arrive in an orderly fashion, with the molars appearing last. Usually your first set of molars appears around age 6, with the second set appearing around age 12. The last set—the wisdom teeth—take much longer than all your other teeth, and about 1 in 5 adults never gets them. Your ancestry plays a role in this. Tasmanian natives almost never have wisdom teeth, while indigenous Mexicans get them almost always. That seems to be due to a genetic mutation that first arose in China more than 300,000 years ago.

Scientists think that changes in the way we eat have changed the shape and function of our mouths, too. In the days of our ancient ancestors, humans lived on lots of foods that require intense chewing. Foods like roots, nuts, leaves, and meats are thought to have made up a big part of our diets in those days. These days most of our foods are softer, and we have knives and forks to do a lot of the "chewing" for us. We've simply outgrown our need for wisdom teeth, but that doesn’t stop them from trying to make an appearance.

Impacted Wisdom Teeth

When teeth don't fully emerge from your gum line, they are considered impacted.

Often your wisdom teeth don't pop out of the gum line (the medical term is "erupt") in the way they should. Sometimes wisdom teeth grow in crooked, pressing against or away from other teeth and are termed "impacted." Estimates of how often new wisdom teeth are impacted vary widely. Some reviews say more than 70% of all new third molars are impacted, while others say less than 40%. This problem sometimes leads to pain, inflammation, and infection, though not always.

One study showed that about 12% of impacted wisdom teeth included more serious symptoms. It is traditionally argued that impacted wisdom teeth crowd other teeth, throwing them out of alignment. However, it has been argued that because wisdom teeth develop from the spongy tissue near the jaw without strong support, they can’t anchor and disrupt the other teeth that are more firmly rooted.


Gum pain and infection near wisdom teeth is known as pericoronitis.

When a wisdom tooth erupts—even partially—it may be vulnerable to pericoronitis. This is the name for gum pain and infection found in 6% to 10% of erupted wisdom teeth. Usually when wisdom teeth erupt naturally, this isn't a problem. It tends to arise in teeth that have emerged from the gum line very slowly—usually the lower wisdom tooth.

Pericoronitis can be either acute or chronic. Acute cases cause severe pain that often radiates into nearby areas in the mouth. It can lead to gum swelling, tightness in the jaw, swollen lymph nodes, difficulty swallowing, and difficulty falling asleep. Chronic cases provoke dull pain that can go away for months, and can leave a bad taste in your mouth. Sometimes exhaustion and pregnancy can cause chronic pericoronitis pain to reoccur.

Studies show that 35% to 43% of patients with pericoronitis recently suffered from a respiratory infection, suggesting these infections may contribute to this oral health problem. Stress may make them more likely, too. It's also more common in women than in men.

Cysts and Tumors

Cysts and tumors can result from impacted wisdom teeth (see area between arrows for cyst).

Impacted wisdom teeth are especially prone to developing cysts and tumors. Cysts are fluid-filled sacs that can develop on the jaw. They can cause bone loss in your jaw. Tumors are abnormal tissue growths that can very rarely be cancerous.

Both cysts and tumors can become large and painful, potentially causing problems in your mouth and even your sinuses if untreated. If a cyst or tumor is causing pain and other problems around your wisdom teeth, your dentist will probably recommend removing those teeth. Fortunately, they're fairly uncommon. Two studies found them in only about 2.5% of removed wisdom teeth.

Other Issues

When they grow in, wisdom teeth may cause health problems, including bone loss.

In addition to pericoronitis, cysts, and tumors, wisdom teeth may show signs of other problems. When they do, they often need to come out. Other problems include:

  • Bone loss near the roots
  • Damage done to adjacent teeth
  • Cavities
  • No room for brushing and flossing around the erupted tooth

Should You Remove Them Just in Case?

Preventive wisdom tooth removal has become controversial over the last decade.

Impacted wisdom teeth have been a driving force in the preventative removal of most wisdom teeth in countries like the United States. Not all health organizations agree that this is necessary, however, and not all countries regularly extract wisdom teeth for preventative reasons.

In 2008, the American Public Health Association rejected the preventative removal of wisdom teeth, arguing that dangers from surgical removal outweigh the risks of leaving the teeth alone. The Cochrane Collaboration found that as many as 60% of all wisdom teeth removals could be eliminated if these teeth were only taken out when pain or other problems emerged. They also disputed the notion that impacted wisdom teeth crowd out other teeth.

Even so, there is evidence that these teeth should come out. Even when they don't show other symptoms, impacted wisdom teeth can cause problems later on. When not removed, between 30% and 60% of these teeth lead to problems within 12 years that require their removal.

What Is Simple Extraction?

Your dentist can perform a simple extraction inside the office.

Have you decided you need your wisdom teeth pulled? This can go one of two ways depending on how exposed your tooth is. If the wisdom tooth has erupted completely, your dentist can pull it out in a procedure called simple extraction.

You can expect your dentist to use numbing agents to kill the pain before proceeding. A tool called an elevator is then used to loosen the teeth. A pair of dental forceps, which look similar to pliers, is then used to actually pull the tooth. Cleaning comes next, followed by gauze to staunch the bleeding.

Recovering From Simple Extraction

You will need to be careful cleaning your mouth after removal.

If you’ve just had a wisdom tooth extracted by the dentist, you will need to follow all instructions to prevent pain and bleeding, and to promote healing. The site of the extraction can ooze with blood and saliva for up to 24 hours. During this time, bite down on a gauze pad for a half hour to an hour at a time, getting a fresh pad after one hour. During the first 24 hours, don’t use straws or spit—both negative and positive pressure in the mouth can harm your recovery. You may want to rinse, but don’t—and don’t brush or floss near the extraction area.

You need to abstain from using tobacco for at least three days. Smoking hampers healing in your mouth. Try to avoid coughing and sneezing, too—allergy medicines can help with this. Refrain from alcohol, and don’t drink anything hot or carbonated either. Avoid spicy foods, which can irritate the area where your tooth was pulled. In general, take it easy. Avoid activity. Prop your head up and lie down, as this can help stop the bleeding.

After the first 24 hours you can brush again, but clean the area around the extraction carefully for the first week. If you experience swelling, rinse your mouth with warm salt water two or three times a day. Typically, swelling improves after two days.

What Is Surgical Extraction?

If your wisdom teeth don’t fully erupt, they will require surgery to be removed.

Surgical extraction is for wisdom teeth that haven't grown in completely. Your dentist won't be equipped to handle this procedure. Instead, you'll need to visit an oral surgeon. This is surgery, so you will be given anesthesia which will numb any pain. You'll find that you can't remember most of the procedure.

Since the teeth haven't erupted yet, your surgeon will need to cut into your gum line to find them. If a tooth is too big to take out in one piece, it will be cut into smaller pieces using a drill. That's especially true if the tooth is coming in at an awkward angle. In some cases, a surgeon may find that the tooth is already infected. If that's so, the surgery must be delayed, and you will need to take antibiotics for 7-10 days before trying again.

Immediately After Surgery

Arrange a ride home in advance of your wisdom tooth surgery.

Since you've been under anesthesia, you do not want to drive home from your surgical extraction. Make sure you have someone with you that can get you home. It's wise to arrange this in advance, as you may still be under an anesthetic fog when it's time to go home.

Your surgeon will often give you a prescription for painkillers. Some patients find they can manage their pain with over-the-counter medications like ibuprofen. But if the surgeon needs to remove bone along with the tooth, the prescription painkillers may be particularly needed. If you do take prescription painkillers, be aware that they can cause nausea. Eating a small amount of food before you take them can help prevent nausea.

Recovery After Surgical Extraction

Recovery from wisdom tooth surgery takes a few days in most cases.

You should plan to take it easy for the first couple of days after your surgery. Your mouth will probably bleed for the first day, so keep enough clean gauze handy to staunch it. Pain and swelling will go down gradually over the next few days, and while it may be painful you should have pain medicine available to provide more comfort.

Follow your surgeon's instructions carefully. Your mouth won't open all the way for about a week. During that time, plan on eating soft foods that don't require too much chewing. You should be able to return to your everyday life after a few days, but keep in mind that your mouth won't be fully healed for another four to six weeks.

Potential Post-Surgery Problems

After surgery, you may experience numbness, infection, or other health problems.

Wisdom tooth surgeries are common, and usually resolve without incident. However, problems can occur. Watch out for signs of infection, and notify the doctor as soon as you notice any. The doctor will drain the infection and put you on antibiotics.

Sometimes sinus problems occur after wisdom tooth surgery. The sinuses are situated close to your upper wisdom teeth, and can be injured during the surgery. These problems can be corrected by your doctor, and antibiotics will most likely be prescribed.

The lower wisdom teeth are situated near a nerve that provide your lips, tongue, and chin with feeling. Sometimes this nerve is injured during surgery and these areas may become numb after surgery. Fortunately, the numbness usually goes away a few weeks later, but in rare cases it may persist. If this is your situation, you may need surgery to fully correct the numbness.

How Common is Dry Socket?

Dry socket is the most common complication of wisdom tooth removal.

Whether your wisdom teeth are removed through simple extraction or surgery, you may end up with a condition called dry socket. Dry socket is the most common complication following wisdom tooth removal. The socket refers to the hole left in your bone where your tooth was removed. Typically, a blood clot forms over the hole, protecting the nerves and bones underneath. However, in the case of dry socket, the clot is either removed or does not form completely. Since the clot isn't there to protect them, your bone and nerves can be left in pain, and healing is hampered.

How common is dry socket? One study found dry socket about 3% of the time following simple extraction, and about 15% of the time after surgery performed by dental students. Another study found that generally, poor oral health was more common in cases involving dry socket, suggesting keeping your mouth clean may help prevent it.

Should You Call Your Doctor?

Some symptoms following tooth removal require a doctor’s care.

Some pain and swelling is normal a few days after surgery. But other complications can be more serious and may need attention. How do you know whether to call the doctor, dentist, or surgeon? Watch for these signs, if they develop, call your health care provider immediately:

  • Your breathing or swallowing is impaired
  • You develop a high fever, which can be a sign of infection
  • You find pus in your mouth or notice foul smells
  • Your pain lasts longer than a week
  • Your mouth continues oozing and bleeding after the second day following surgery
  • Your jaw or face are still swollen after the first few days

Why We Have Wisdom Teeth: Surgery, Pain, and Treatment

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