Swollen gums around a wisdom tooth almost always point to a condition called pericoronitis, an infection of the soft tissue that partially covers an erupting or impacted third molar. It’s one of the most common dental problems in young adults, and roughly 37% of people have at least one impacted wisdom tooth that can trigger it. The good news: with proper care, the swelling typically resolves within one to two weeks.
How the Infection Starts
As a wisdom tooth pushes through the gumline, it often doesn’t fully emerge. A flap of gum tissue, called an operculum, drapes over part of the tooth’s crown and creates a small pocket between the gum and the tooth surface. That pocket is nearly impossible to clean with a toothbrush or floss. Food particles slip underneath the flap and sit there, feeding bacteria in a warm, moist, oxygen-poor environment where they thrive.
The bacteria involved are mostly the same species that cause gum disease elsewhere in the mouth, but the pocket gives them a protected breeding ground. As they multiply, the surrounding tissue becomes inflamed, tender, and swollen. The upper wisdom tooth can also bite down onto the swollen flap, making the irritation worse and sometimes introducing new bacteria into the wound.
The Role of Impaction
Not every wisdom tooth comes in straight. The most common problem is mesial impaction, where the tooth angles forward toward the next molar instead of growing upward. Horizontal impaction, where the tooth lies completely on its side, is less common but causes significant pressure on neighboring teeth and bone. In a soft tissue impaction, the tooth has cleared the jawbone but remains trapped under the gum. All of these scenarios make the gum pocket deeper and harder to keep clean, raising the risk of repeated swelling episodes.
Even wisdom teeth that appear to be erupting normally can cause pericoronitis if the gum flap lingers for weeks or months while the tooth slowly works its way out. The longer the flap exists, the more opportunities bacteria have to colonize it.
What It Feels Like
The most obvious symptom is a puffy, tender area of gum at the very back of your mouth, usually on the lower jaw. You might also notice:
- Pain when chewing or when the opposite tooth presses into the swollen gum
- A bad taste from pus or trapped debris draining from the pocket
- Difficulty opening your mouth fully, especially if the swelling extends into the jaw muscles
- Swollen lymph nodes under the jaw on the affected side
- Low-grade fever if the infection is progressing
Mild cases may only involve soreness and slight puffiness. More severe infections spread into the cheek, throat, or the floor of the mouth, and the pain can become constant rather than only flaring when you eat.
When Swelling Becomes Dangerous
Most pericoronitis episodes are uncomfortable but manageable. Rarely, the infection can spread into the deep spaces of the neck, a life-threatening condition called Ludwig’s angina. Warning signs include difficulty breathing, difficulty swallowing, a swollen or protruding tongue, severe neck swelling or discoloration, and a fever that keeps climbing. If you experience any combination of these, go to an emergency room. A dental infection that reaches the airway can become critical within hours.
Short of that emergency, you should still see a dentist promptly if the swelling doesn’t improve after two or three days of home care, if you develop a fever, or if you can barely open your mouth. These signs suggest the infection is spreading beyond the gum flap and may need professional treatment.
What Your Dentist Will Do
The first step is flushing the pocket beneath the gum flap with an antiseptic solution to clear out trapped food and bacteria. This irrigation alone often provides noticeable relief. If the infection is more established, your dentist may prescribe a short course of antibiotics, typically for two to three days after any surgical treatment. The first-line choice for pericoronitis is usually metronidazole, with amoxicillin as an alternative.
A dental X-ray (or sometimes a CT scan for severe cases) helps determine what’s happening beneath the surface. Your dentist will look at the angle of the tooth, how deep it sits in the bone, and whether any cysts have formed around it. These findings guide the next decision: whether to keep the tooth or remove it.
Gum Flap Removal vs. Extraction
If your wisdom tooth appears to be erupting normally and has enough room to come in straight, your dentist may recommend removing just the gum flap in a minor procedure called an operculectomy. This eliminates the pocket where bacteria collect and lets the tooth finish emerging without obstruction. Recovery is quick, though symptoms can occasionally return if the tissue regrows.
Extraction is the more common recommendation when the wisdom tooth is partially or fully impacted, angled into the neighboring molar, or has already caused repeated infections. In many cases, the dentist will also remove the opposing upper wisdom tooth at the same time. Without its partner below, that upper tooth can over-erupt and bite into the healing gum, setting up the same cycle of irritation.
What You Can Do at Home Right Now
While you’re waiting for a dental appointment, a few measures can reduce pain and keep the infection from worsening. Rinse gently with warm salt water (about half a teaspoon of salt in a cup of warm water) several times a day to help draw out fluid and reduce bacterial load. Over-the-counter pain relievers like ibuprofen help with both pain and inflammation. Avoid chewing on the affected side, and stay away from very hot or spicy foods that can irritate the tissue further.
Try to keep the area as clean as possible. A soft-bristled toothbrush angled carefully around the gum flap can dislodge some trapped debris. An oral irrigator on a low setting can flush the pocket more effectively than rinsing alone. These steps won’t cure the infection, but they can slow it down and make you more comfortable until you get professional care.
Recovery Timeline
With treatment, pericoronitis typically clears up within one to two weeks. Mild cases that respond to irrigation and improved hygiene may feel better in just a few days. If antibiotics are prescribed, you’ll usually notice a significant drop in swelling within 48 to 72 hours. After extraction, the socket itself takes several weeks to fully heal, but the gum swelling and pain from the infection resolve much sooner.
Pericoronitis has a frustrating tendency to come back, especially if the underlying cause (a partially erupted or impacted tooth) hasn’t been addressed. About half of people who experience one episode will have another. If your swelling keeps returning every few weeks or months, extraction is generally the most reliable way to break the cycle for good.