The clearest signs of wisdom teeth needing to be removed are gum infections that keep coming back, pain at the back of the jaw, and damage to the molar next door. A healthy wisdom tooth can often stay. This blog will walk you through each sign, what the X-ray shows and when wisdom teeth removal is the right call.
Why wisdom teeth cause problems
Wisdom teeth are the third molars, the last teeth to come in, usually between the ages of 17 and 25. By then the second molars have taken most of the space at the back of the jaw, so a wisdom tooth often cannot come through straight. A tooth that stays partly or fully trapped under the gum or in the bone is called impacted.
Impaction causes most of the trouble. A tooth that only half breaks through leaves a flap of gum that traps food and bacteria where a toothbrush cannot reach. A tooth that grows at an angle can press against the molar in front and create a pocket that is just as hard to clean. The signs below are the ways those problems show up.
Early warning signs of wisdom tooth problems
Wisdom tooth problems usually start small and build over weeks or months. The early signs are:
- swelling or tenderness in the gum behind the last molar
- pain when chewing on that side
- a stiff or sore jaw
- difficulty brushing or flossing behind the back teeth
- a bad taste or bad breath from the back of the mouth
None of these means the tooth has to come out, but each is worth showing your dentist, who can check the tooth and take an X-ray in one visit.
Persistent pain at the back of the jaw
Pain that lasts or keeps returning at the back of the jaw is one of the most common reasons wisdom teeth are removed. It comes from a tooth pressing against bone or the next molar as it tries to erupt, or from infection under the gum.
The pain often gets worse when you chew or open wide. It can spread to the temple, because the chewing muscles run from the jaw up the side of the head, and towards the ear, because the jaw joint and ear canal sit side by side. Our guide to wisdom tooth ear pain explains how to tell a tooth from an ear problem.
Repeated gum infections around the tooth
Pericoronitis is an infection of the gum flap over a partly erupted wisdom tooth. It causes swelling, tenderness, a bad taste and often trouble opening the mouth. The area under the flap is almost impossible to clean, so the infection tends to come back.
How often it comes back decides whether the tooth should go. NICE's guidance on wisdom teeth says a first episode of pericoronitis, unless it is particularly severe, should not be treated as a reason for surgery, but a second or later episode should be. A first flare can often be settled with cleaning under the flap and rinses.
Swelling that spreads down the neck or towards the eye, a fever with a swollen face, or trouble swallowing or breathing means the infection has spread. That needs the ER, or a same-day emergency visit if breathing and swallowing are unaffected.
Damage to the molar in front
A wisdom tooth that grows at an angle can damage the second molar in front of it, often without any pain. Plaque collects in the gap between the two teeth, where you cannot brush, and the back of the second molar decays or loses bone.
This is common. In a 2023 study of 353 panoramic X-rays in Clinical, Cosmetic and Investigational Dentistry, 47.5% of cases with an impacted lower wisdom tooth had decay on the back of the second molar, and root resorption showed up in 20.4% of second molars beside an angled wisdom tooth. Losing the second molar to protect a wisdom tooth is a bad trade, which is why this sign carries so much weight.
Signs you might notice are food packing between the last two teeth, sensitivity on the back molar, or floss that shreds there. Often the dentist spots it first on an X-ray.
Jaw stiffness or difficulty opening the mouth
Swelling around a wisdom tooth can irritate the chewing muscles beside it and make them tighten, so you cannot open your mouth fully. Dentists call this limited opening trismus. It usually comes with tenderness at the back of the jaw and eases once the infection settles.
Jaw stiffness can also come from the jaw joint itself, with clicking or pain in front of the ear. A dental exam checks both the tooth and the joint, because the treatment for each is different.
Headaches related to wisdom teeth
A wisdom tooth can cause headaches, usually on the same side, around the temple or behind the eye. Pressure and infection at the back of the jaw tighten the chewing muscles, and pain travels along the same nerve that serves the teeth and the side of the face.
These headaches often feel like tension headaches and come with jaw soreness or swelling behind the last molar. Our guide to wisdom tooth headaches covers the patterns and how to tell them from TMJ pain or migraine.
Signs dentists see on dental imaging
Some of the most important signs only show on an X-ray. A panoramic X-ray shows all four wisdom teeth, their roots and the nerve canal in the lower jaw in one image. Dentists look for:
- a wisdom tooth angled towards the second molar, which makes damage to that molar more likely
- decay or bone loss on the back of the second molar
- not enough room for the wisdom tooth to come through
- roots close to the inferior alveolar nerve, which runs through the lower jaw to the lip and chin and needs careful planning if the tooth is removed
- a cyst forming in the sac around an impacted tooth, which is rare but a firm reason to remove it
Our guide to impacted wisdom teeth explains the impaction types and what each means for surgery.
Age and timing of wisdom tooth removal
Wisdom teeth are usually checked in the late teens and early twenties, when their position is clear on an X-ray but the roots are not fully formed.
- Around 16 to 18, the teeth are still developing in the bone, and an X-ray shows where they are heading.
- Between 18 and 25, most wisdom teeth finish forming and try to erupt. This is the most common time to decide.
- After 25, removal can be more complex, because the roots are fully formed and the bone is denser. Age over 24 is also linked to a higher risk of irritating the nerve in the lower jaw.
Age alone is never the reason to remove a tooth. It changes how easy removal is, not whether it is needed.
When monitoring may be appropriate
Not every wisdom tooth needs to come out. A tooth that is fully through, upright, pain-free and easy to clean, with healthy gum around it, can stay.
The guidance differs on teeth that are impacted but healthy. NICE told the UK's NHS to stop removing pathology-free impacted wisdom teeth as a precaution, and to remove them only when there is disease. The ADA's guide to wisdom teeth adds that teeth that stay should keep being checked, because problems can still develop later and the risk of complications grows with age.
Monitoring means an exam at regular checkups and an X-ray when your dentist needs one, so changes in position, decay or gum health are caught early.
When removal may be recommended
Removal is recommended when a wisdom tooth is already causing disease, or when an X-ray shows damage that will keep getting worse. The ADA lists pain, infection, cysts, tumours, damage to neighbouring teeth, gum disease and decay that cannot or should not be repaired. In practice, dentists recommend removal for:
- a second or later episode of pericoronitis
- decay or bone loss on the second molar caused by the wisdom tooth
- decay in the wisdom tooth that cannot sensibly be filled
- an abscess or infection around the tooth
- a cyst or other disease around an impacted tooth
- pain that keeps coming back from a tooth that cannot erupt
Each tooth is judged on its own, so you may need one removed and the others watched. Our page on wisdom tooth extraction in San Diego explains the procedure and sedation options.
What happens after removal
Once a problem wisdom tooth is out, the pressure and infection behind the pain go with it, and most patients notice the swelling and soreness ease as the area heals. Most people are back to normal within 1 to 2 weeks. Our wisdom teeth recovery day by day guide covers swelling, food and the warning signs of dry socket.
What Dr. Dan Javaheri looks for
Dr. Daniel Javaheri, lead dentist at Smiles By Design, checks wisdom teeth at routine exams and with a panoramic X-ray when they start to erupt or cause symptoms. He looks at three things: whether the tooth can come through and be kept clean, whether it is harming the molar in front, and how close its roots sit to the nerve. Because wisdom teeth develop in limited space at the back of the jaw, he finds that early evaluation catches problems while removal is still straightforward.
Frequently Asked Questions
How do I know if my wisdom teeth need to be removed?
The signs are a gum flap that keeps getting infected, ongoing pain or swelling at the back of the jaw, decay on the wisdom tooth or the molar in front, and a cyst or damage on an X-ray. A dentist confirms it with an exam and a panoramic X-ray in one visit.
Do all wisdom teeth need to be removed?
No. A wisdom tooth that is fully through, pain-free, easy to clean and surrounded by healthy gum can stay. NICE advises against removing healthy impacted wisdom teeth as a precaution. Teeth that stay should still be checked at regular visits, because problems can develop later.
Can wisdom teeth cause headaches?
Yes. Pressure and infection around a wisdom tooth can tighten the chewing muscles and send pain to the temple or behind the eye, usually on one side. The headache often comes with jaw soreness or swelling behind the last molar and eases once the tooth is treated.
When are wisdom teeth usually removed?
Wisdom teeth are usually removed between the ages of 18 and 25, when they finish forming and problems become clear. Removal is often simpler before 25, because the roots are not fully formed. The timing depends on the tooth, not the age: a healthy tooth can stay at any age.
How much does wisdom teeth removal cost?
At California in-network rates, wisdom teeth removal costs $145 per tooth for an erupted tooth up to $462 for a complicated bony impaction, plus the X-ray and any sedation.
When is wisdom tooth pain an emergency?
Wisdom tooth pain is an emergency when it comes with trouble breathing or swallowing, swelling spreading down the neck or towards the eye, or a fever with a swollen face. Call 911 or go to the ER. Pain and gum swelling without those signs needs a same-day dental visit.
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