When Do Wisdom Teeth Come In? Ages, Signs and Timeline

For most people the answer is the late teens to mid-twenties. Here is how that fits with the rest of tooth development:

• Around age 6: the first permanent molars come in behind the baby teeth
• Around ages 11 to 13: the second molars arrive
• Roughly ages 17 to 25: the third molars, or wisdom teeth, begin to erupt, if they are going to

The teeth themselves start forming inside the jawbone years before they appear. They can often be seen developing on dental x-rays in the early to mid teens, long before anything is felt in the mouth.

Timing varies widely. It is not unusual for the four teeth to appear at different times, even years apart. Some people notice a wisdom tooth for the first time in their late twenties or thirties, and less commonly later than that. Others reach adulthood with wisdom teeth that are fully formed but remain under the gum or bone, which is called impaction.

If a child or young teen has pain at the very back of the mouth, wisdom teeth are an unlikely cause at that age. The second molars are a more common explanation, but pain in a child's mouth is worth a call to their dentist either way.

Some people feel nothing and only learn their wisdom teeth have erupted when a dentist points it out. When there are signs, they commonly include:

• A dull ache or feeling of pressure at the very back of the jaw, behind the last molar
• Tender, red or slightly swollen gum in that spot
• A hard white edge or point visible through the gum
• A flap of gum partly covering the new tooth
• Mild jaw stiffness or soreness when chewing on that side
• Food catching behind the last molar
• A bad taste or bad breath coming from the area
• Discomfort that comes for a few days, settles, and returns weeks or months later

These signs overlap with other problems, including gum infection around a partly erupted tooth, decay in the neighboring molar, a cracked tooth and jaw joint problems. Pain at the back of the mouth in a young adult is often related to a wisdom tooth, but not always, and symptoms alone cannot confirm it.

Eruption is rarely a single event. Wisdom teeth coming in tend to move in spurts: a few days or weeks of pressure and tenderness as the tooth shifts, then a quiet period, then another spurt. From the first sign to a fully erupted tooth can take months, and it is commonly spread over several years.

Three broad outcomes are possible:

• Full eruption. The tooth comes all the way through, lines up with the other molars and can be cleaned like any other tooth.
• Partial eruption. The tooth breaks through the gum and then stalls, leaving part of the crown covered by gum. This is the situation most often linked with trouble, because food and bacteria can collect under the gum flap.
• No eruption. The tooth stays beneath the gum or bone. It may sit quietly for years, or it may eventually cause problems that only show on an x-ray.

There is no reliable way to predict from symptoms how far a particular tooth will get. Whether it has enough room and what angle it sits at are the main factors, and both are judged from an exam and x-rays.

No. A meaningful share of people are missing one or more wisdom teeth from birth, meaning the tooth never formed. Estimates of how common this is vary widely between studies and between populations. Having four, three, two, one or none are all recognized variations, and a small number of people have extra molars behind the wisdom teeth.

Reasons you might not see four wisdom teeth:

• They never developed. This tends to run in families and is generally thought to be genetic.
• They are impacted. The teeth exist but are trapped under gum or bone and cannot be seen in the mouth.
• They have not erupted yet. This is common in the late teens and early twenties.
• They were removed. People do not always recall how many were taken out.

Not seeing or feeling wisdom teeth does not tell you which of these applies. An impacted tooth and a tooth that never formed feel identical from the outside, which is one reason dentists use x-rays to check.

Wisdom teeth are the last to arrive, and by the time they do, the other 28 teeth have usually claimed the available space. When there is not enough room behind the second molars, a wisdom tooth may come in tilted, come in only partway, or stay buried.

A partly erupted wisdom tooth can be hard to keep clean. The gum around it can become inflamed or infected, a condition called pericoronitis, which commonly causes pain, swelling, a bad taste and sometimes difficulty opening the mouth. Hard-to-reach wisdom teeth and the molars in front of them can also be more prone to decay and gum problems.

Not all impacted or partly erupted wisdom teeth cause trouble, and not all wisdom teeth need to come out. Whether to remove or monitor them is an individual decision made with a dentist or oral surgeon, based on what the exam and x-rays show.

Dentists commonly start keeping an eye on wisdom teeth during the mid to late teens. The usual tool is a panoramic x-ray, a single image that shows all of the teeth, both jaws and the developing third molars in one view. In some cases a three-dimensional scan is recommended to see how close a tooth's roots are to nearby nerves or the sinus.

From the exam and imaging, a dentist can usually tell you:

• How many wisdom teeth you have
• How far their roots have developed
• What angle each one sits at
• Whether there appears to be room for them
• Whether there are signs of decay, cysts or damage to neighboring teeth

If you are in your late teens or twenties and have never had your wisdom teeth assessed, it is reasonable to ask about them at your next checkup. If you are older, have never had them looked at and nothing hurts, it is still a fair question to raise, since some problems develop without symptoms.

Mild eruption soreness often settles within several days. While you wait for an appointment, these measures are commonly used for temporary comfort. They do not treat an infection or fix a tooth that lacks room.

• Keep the area as clean as you can with a soft toothbrush, including gently behind the last molar
• Rinse gently with warm salt water
• Choose softer foods, and chew on the other side if one side is sore
• Hold a cold pack against the outside of the cheek for short periods
• Over-the-counter pain relievers are an option for some people. Follow the package label and ask a pharmacist, dentist or doctor first, especially if you are pregnant, take blood thinners, or have kidney, liver, stomach or heart conditions.

Do not cut or lift the gum over the tooth yourself. Do not place aspirin, alcohol or undiluted essential oils on the gum. Do not take leftover antibiotics or antibiotics prescribed for someone else. If soreness lasts more than several days, keeps coming back or is getting worse, book a dental visit.

Call a dentist for an appointment if you have:

• Pain at the back of the mouth that lasts more than a few days or keeps returning
• Gum around a back tooth that is swollen, red or leaking pus
• A persistent bad taste or bad breath from the area
• Difficulty opening your mouth fully
• Pain when biting, or pain in the molar in front of the wisdom tooth
• Tender, swollen glands under the jaw
• Any fever alongside mouth or jaw pain, in which case ask to be seen the same day

Call 911 or go to the nearest emergency room if you have:

• Trouble breathing or swallowing
• Swelling spreading toward the eye, down the neck, or under the jaw or tongue
• Fever together with facial swelling
• Bleeding that will not stop with firm pressure

People who are pregnant, have diabetes or a weakened immune system, take blood thinners, take or have taken bisphosphonates or similar bone medications, or have had radiation to the head or neck should call their dentist or doctor sooner instead of waiting to see whether symptoms settle. Infections can move faster and treatment planning is more involved in these situations.

If you are not sure how urgent your symptoms are, the urgency checker on this site can help you think it through, but it does not replace a call to a dentist.