Nothing may happen at all, or you could develop infections, damage to neighboring teeth, cysts, or chronic gum disease. The outcome depends almost entirely on whether your wisdom teeth are impacted (stuck beneath the gum or bone) or have fully erupted into a functional position. Millions of people keep their wisdom teeth for life without problems, but impacted or partially erupted wisdom teeth carry real risks that tend to increase with time.
The Most Common Problem: Gum Infection
When a wisdom tooth only partially breaks through the gum, a flap of tissue sits over part of the tooth. Bacteria and food debris collect under that flap, creating a breeding ground for infection called pericoronitis. This is the single most common complication of retained wisdom teeth, and it causes pain, swelling, a bad taste in your mouth, and difficulty opening your jaw fully.
A first episode of pericoronitis is usually manageable with antibiotics and careful cleaning. The UK’s National Institute for Health and Care Excellence (NICE) specifically notes that a single mild episode isn’t reason enough for surgery. But recurrent episodes are a different story. Each infection carries a small risk of spreading into the deeper spaces of the head and neck, including areas near the throat and airway. Untreated pericoronitis can progress to facial swelling, fever, difficulty swallowing, voice changes, and in rare cases, life-threatening airway compromise.
Damage to the Tooth Next Door
An impacted wisdom tooth doesn’t just sit idle. If it’s angled toward the neighboring second molar, it can press against that tooth over months or years, causing two types of damage. The first is decay: the tight contact point between the two teeth is nearly impossible to keep clean, so cavities form on the back surface of the second molar. The second is root resorption, where sustained pressure from the wisdom tooth gradually dissolves the root of the adjacent tooth. In one documented case, a woman lived with an impacted wisdom tooth for over a decade before imaging revealed that the tip of her second molar’s root had completely disappeared from the pressure. That damage is irreversible.
This is one of the stronger arguments for removing impacted wisdom teeth that appear to be leaning into the second molar, even when they aren’t causing pain yet. Losing or needing major treatment on a second molar is a far bigger problem than losing a wisdom tooth you never needed.
Cysts and Tumors
Every tooth develops inside a small sac of tissue called a follicle. When a wisdom tooth stays impacted, that follicle remains in the jawbone and can occasionally fill with fluid, forming a dentigerous cyst. These cysts expand slowly and silently, sometimes hollowing out a section of jawbone before they’re detected on a routine X-ray. In a study of nearly 4,000 impacted third molars, about 1.5% were associated with cysts or tumors. That number sounds small, but the consequences can be significant: cyst removal sometimes requires taking a portion of jawbone with it, and a small percentage of these growths turn out to be more aggressive tumors that need extensive surgery.
Does Keeping Them Cause Crowding?
This is one of the most persistent beliefs about wisdom teeth, and the evidence doesn’t support it well. Two randomized controlled trials tracked teenagers with impacted wisdom teeth over three to five years, comparing those who had them removed with those who didn’t. Neither study found a clinically meaningful difference in how much the front teeth shifted or crowded. One trial did measure a small statistical difference in arch length (about one millimeter), but the researchers themselves didn’t consider it significant enough to matter. Lower front teeth tend to crowd with age regardless of whether wisdom teeth are present. So if crowding prevention is your main reason for considering extraction, it’s not a strong one.
What Happens If You Wait Until You’re Older
If you skip extraction in your late teens or early twenties and need the surgery later, the procedure gets harder. Jawbone becomes denser with age, roots continue to grow and may wrap around the nerve that runs through the lower jaw, and healing slows down. The rate of nerve injury during extraction peaks in the 40 to 49 age group. While permanent nerve damage (resulting in lasting numbness of the lip or tongue) occurs in less than 1% of all extractions, the risk of temporary numbness and incomplete sensory recovery is higher in older patients. Bone ankylosis, where the tooth root fuses directly to the jawbone, also becomes more common after middle age, making the tooth significantly harder to remove.
This is why the American Association of Oral and Maxillofacial Surgeons recommends making a decision about wisdom teeth before the middle of your third decade, roughly by age 25. That doesn’t mean you must have them out. It means you should have a clear plan: either remove them or commit to regular monitoring with X-rays so problems are caught early.
When Keeping Them Is Perfectly Fine
Not all wisdom teeth are impacted. Some erupt fully, align well with the opposing tooth, and function like any other molar. If your wisdom teeth have come in straight, you can brush and floss around them normally, and X-rays show no signs of cysts or damage to adjacent teeth, there’s no medical reason to remove them. NICE guidelines are explicit: the routine preventive removal of healthy, disease-free wisdom teeth should not be done. The American guidelines agree that in the absence of disease or significant risk of disease, active surveillance (regular dental checkups and periodic X-rays) is the appropriate approach.
The key word is “active.” Keeping your wisdom teeth means committing to monitoring them. A wisdom tooth that’s problem-free at 25 can develop a cyst at 40 or start eroding the neighboring tooth at 35. Your dentist should be checking them at each visit, and you should be getting periodic X-rays to look for changes beneath the gumline that you wouldn’t feel.
Signs That Something Has Gone Wrong
If you’ve chosen to keep your wisdom teeth, watch for these changes:
- Recurring pain or tenderness in the back of your jaw, especially on one side
- Swollen, red, or bleeding gums around the wisdom tooth area
- A persistent bad taste or bad breath that doesn’t improve with brushing
- Difficulty opening your mouth fully or pain when chewing
- Swelling in the cheek or jaw that worsens over hours
- Fever, difficulty swallowing, or facial swelling spreading toward the neck, which suggest the infection may be spreading and needs urgent care
Many of these symptoms come and go, which makes it easy to dismiss them. But repeated flare-ups of pericoronitis or worsening pain are strong signals that the tooth is causing disease and removal is likely the best path forward.