Most people expect their wisdom teeth to emerge at some point during the late teens and early adult years. But while many people have one to four wisdom teeth, some people don’t have any at all.

Wisdom teeth are the third set of molars in the back of your mouth. Although it’s common to get wisdom teeth, they can cause issues.

You can experience pain as the teeth break through the gums. And if there isn’t enough space in your mouth for your wisdom teeth, they can become impacted below the gum surface. In either case, you may need to have them removed.

A dental X-ray can reveal whether you have third molars. Not having any wisdom teeth might come as a surprise, and you might think there’s something wrong with your oral health. But the reality is, it’s perfectly okay not to have these molars.

According to the Dental Research Journal, it’s estimated that anywhere from 5 to 37 percent of people are missing one or more of their third molars. The reason is unknown, but lack of these teeth could involve genetics. So if one of your parents doesn’t have wisdom teeth, you may not have them either.

Other factors that might influence the lack of wisdom teeth include environment, diet, and chewing function.

Keep in mind, though, just because you can’t see your wisdom teeth doesn’t mean they don’t exist. Sometimes, wisdom teeth become impacted or stuck in the gums. And as a result, they don’t fully emerge.

But even if you can’t see your wisdom teeth, a dental X-ray can detect an impacted tooth. Your dentist may recommend removal of the tooth to avoid gum infections and pain. Or, your dentist may monitor your teeth and only remove an impacted wisdom teeth if it starts to cause problems.

Wisdom teeth emerge at different ages. Typically, you can expect your third molars to come in around your late teens or early adult years, between the ages of 17 and 21. However, some people get their wisdom teeth earlier, and some people get them later.

If you need your wisdom teeth removed, it’s easier to do so when you’re younger. Not that you can’t schedule surgery later in life, but when you’re young, the bones around your gums are softer and the nerve roots in your mouth haven’t completely formed.

As a result, it’s easier to remove these teeth. If you wait until later, removal can be more difficult and more painful.

Wisdom teeth removal is a common procedure because there’s often only room for 28 teeth in the mouth. If all four of your wisdom teeth come in, resulting in 32 teeth, this may lead to overcrowding.

Since the mouth only has space for about 28 teeth, what is the purpose of wisdom teeth?

One belief is that wisdom teeth served as replacement teeth for our distant ancestors. Today, we eat foods that are soft or tender, and most people practice good oral hygiene. Both factors help reduce the likelihood of losing teeth.

Since our ancestors ate different types of foods — maybe not as soft — and didn’t have regular dental appointments, they might have dealt with gum and teeth problems like tooth decay or tooth loss. If so, wisdom teeth possibly provided extra teeth for chewing.

Today, wisdom teeth serve little purpose, and often cause more harm than good.

Of course, there’s no rule that says you have to remove a wisdom tooth that emerges — especially if you have space in your mouth. Some people choose removal even when their wisdom teeth don’t cause problems to avoid complications down the road. And some people don’t seek removal until they have pain.

If you put off removal because you’re not having any symptoms, you may need to eventually schedule oral surgery. Wisdom teeth tend to cause problems the longer they remain in the mouth.

Common complications associated with wisdom teeth include:

  • Tooth pain. Pain in the back of the mouth is a common sign of emerging wisdom teeth. Tooth pain can start off as mild and intermittent. The gums in the back of your mouth may hurt for a few days, and then the pain subsides. This can happen on and off over several months or years. However, pain can gradually increase to the point where it becomes difficult to chew or talk. Pain is often due to the tooth pressing on the nerves in the mouth.
  • Swelling and redness. Along with pain, signs of an emerging wisdom tooth include redness or swelling in the gums around your third molars.
  • Impacted tooth. Sometimes, your jaw bone and other teeth prevent wisdom teeth from coming in, and the teeth remain trapped beneath the gum line. This can cause severe pain in the mouth. Other signs of an impacted wisdom tooth include pain around your molars, but no sign of an emerging tooth. You may also develop a cyst in the back of your mouth.
  • Oral infections. As your wisdom teeth emerge, bacteria can get trapped in your gums, leading to an oral infection. Signs of an infection include:
    • pain
    • redness
    • swelling
    • tenderness in your jaw
    • bad breath
    • a foul taste in the mouth
  • Cavities. Food may also get trapped in the gums around third molars, which can cause a cavity on your emerging third molar. Teeth in front of wisdom teeth can also get cavities because there isn’t enough space to brush or floss.
  • Shifting teeth. When there isn’t enough space in your mouth for wisdom teeth, other teeth can shift out of place as these teeth emerge. They may become misaligned or crooked.

If you have tooth pain or see an emerging wisdom tooth, see your dentist. Your dentist can take X-rays to determine how many wisdom teeth you have. If you don’t already have a dentist, you can browse options in your area through the Healthline FindCare tool.

When you’re experiencing pain or other problems, your dentist will likely recommend removal by an oral surgeon. This helps reduce the risk of complications like:

  • infections
  • bone loss
  • nerve pain
  • cavities
  • shifting teeth

If your wisdom teeth aren’t causing any problems or complications, your dentist may monitor the teeth and recommend removal at a later time. Keep in mind, though, wisdom teeth removal becomes harder later in life. So if you’re having problems, remove the bothersome teeth early.

Some people don’t have wisdom teeth. So if you’re fortunate enough to be without third molars, you can avoid removal of these teeth. If you have wisdom teeth, but they’re not causing problems, continue to schedule regular dental visits every 6 months.

Your dentist can keep a close eye on these emerging teeth and then recommend removal when it’s appropriate.