Wisdom Teeth
Pericoronitis is inflammation, often with infection, of the gum flap covering a partially erupted tooth, most often a lower wisdom tooth. Food and bacteria get trapped under the flap, causing pain, swelling, a bad taste, and sometimes difficulty opening the mouth. Mild cases often settle with cleaning and warm salt-water rinses, but repeated episodes are a common reason to have the wisdom tooth removed.
Key takeaways
- Pericoronitis usually affects lower wisdom teeth that have only partly come through the gum.
- Symptoms include gum swelling behind the last molar, pain when biting, bad taste, and jaw stiffness.
- Treatment ranges from cleaning under the flap and rinses to antibiotics for spreading infection and removal of the tooth.
- Trouble swallowing or breathing, or swelling spreading into the cheek or neck, needs urgent care.
What Causes Pericoronitis?
When a wisdom tooth does not have enough room to erupt fully, a flap of gum (the operculum) can remain over part of the crown. The space under the flap is almost impossible to clean. Food particles and bacteria collect there, and the gum becomes inflamed. The upper wisdom tooth can also bite down on the swollen flap, making it worse.
It is most common in the late teens and twenties, when wisdom teeth are trying to erupt, and flare-ups are often triggered by a cold, stress, fatigue, or a period of less thorough brushing.
Symptoms Of Pericoronitis
- Red, swollen, tender gum behind the last lower molar
- Pain when biting or chewing on that side, sometimes spreading to the ear
- A bad taste or pus from under the gum flap
- Bad breath
- Difficulty opening your mouth fully (trismus)
- Swollen lymph nodes under the jaw
- Fever or feeling unwell in more severe cases
Mild, Moderate, Or Urgent?
| Severity | What you may notice | What to do |
|---|---|---|
| Mild | Sore, swollen gum flap; mild pain | Clean the area carefully and use warm salt-water rinses; book a dental or oral surgery assessment |
| Moderate | Pain when chewing, bad taste, some difficulty opening | See your dentist or the oral surgery office promptly; cleaning under the flap and sometimes antibiotics are needed |
| Urgent | Swelling of the cheek, jaw, or neck, fever, difficulty swallowing or breathing | Go to the emergency department or call for urgent care immediately |
Home Care While You Arrange An Appointment
These steps can ease mild symptoms but do not replace an assessment:
- Rinse gently with warm salt water (about one teaspoon of salt in a cup of warm water) several times a day, especially after meals.
- Brush carefully around the back of the mouth with a soft toothbrush.
- Use over-the-counter pain relievers as directed on the package if they are safe for you.
- Eat soft foods and chew on the other side.
Avoid placing aspirin directly on the gum, and do not try to cut or drain the flap yourself.
How Is Pericoronitis Treated?
- Cleaning. Your dentist or oral surgeon flushes food and debris from under the gum flap.
- Antibiotics, when infection is spreading or you have fever or swelling. They are not needed for every case.
- Pain control and instructions for rinses and hygiene.
- Treating the cause. Once the acute episode settles, the surgeon discusses whether the wisdom tooth, and sometimes the opposing upper wisdom tooth, should be removed.
X-rays or 3D imaging show how the tooth is positioned and whether it can erupt fully. Our antibiotics after wisdom teeth removal guide explains how surgeons decide when antibiotics are needed.
When Should The Wisdom Tooth Be Removed?
A single mild episode may settle and never return, especially if the tooth later erupts fully and can be cleaned. However, when a wisdom tooth does not have room to come in, pericoronitis tends to recur. The UK's National Institute for Health and Care Excellence (NICE) guidance on wisdom teeth identifies a second or subsequent episode of pericoronitis, or a single severe episode, as an appropriate reason for removal.
"Plaque formation is a risk factor but is not in itself an indication for surgery." — National Institute for Health and Care Excellence, Guidance on the extraction of wisdom teeth (TA1)
Other reasons to consider removal include decay in the wisdom tooth or the molar in front of it, gum disease around the tooth, cysts, and damage to neighbouring teeth. Learn more about when wisdom teeth should be removed and about wisdom teeth removal at our Waterloo office.
Removal is usually scheduled once the acute infection has calmed down, which makes surgery more comfortable and reduces complications.
Wisdom Tooth Infections: Care In Waterloo Region
Our office at 96 Union Street East, near Uptown Waterloo, treats painful and infected wisdom teeth for patients from Waterloo, Kitchener, Cambridge, Guelph, and Stratford. Patients with pain or infection are triaged to be seen as soon as possible, and removal is planned once the flare-up has settled. Call +1 (519)-743-7811, or ask your dentist to send a referral. For severe swelling, fever, or trouble swallowing or breathing, go to the nearest emergency department.
Sources
- National Institute for Health and Care Excellence. Guidance on the extraction of wisdom teeth (TA1). 2000.
- Wisdom teeth, Dr. Kevin J. McCann Oral & Maxillofacial Surgery.
FAQ
Can Pericoronitis Go Away On Its Own?
Mild pericoronitis sometimes settles with careful cleaning and salt-water rinses, but the trapped-food problem usually remains while the gum flap is present. Many patients have repeated flare-ups until the tooth erupts fully or is removed.
Is Pericoronitis An Emergency?
Most cases are not emergencies, but they should be assessed soon. Swelling spreading into the cheek or neck, fever, or any difficulty swallowing or breathing requires urgent care.
Do I Need Antibiotics For Pericoronitis?
Not always. Cleaning under the gum flap is the main treatment. Antibiotics are added when infection is spreading or you have systemic signs such as fever.
Can The Gum Flap Be Removed Instead Of The Tooth?
Removing the flap (operculectomy) is sometimes considered when the tooth is upright and has room to erupt. If there is not enough room, the flap often grows back and removing the tooth is more predictable.
Should I Have Wisdom Teeth Removed During A Flare-Up?
Surgeons usually prefer to calm the infection first and schedule removal once swelling and pain have settled, unless urgent treatment is needed.
This article is general patient education and does not replace an examination, diagnosis, or the written instructions from your own surgeon or dentist. If you have heavy bleeding, trouble breathing or swallowing, or rapidly spreading swelling, call the office or go to the nearest emergency department.