A flap of gum over a wisdom tooth is common, especially in your late teens and twenties, when wisdom teeth are still coming through. Most of the time it causes no trouble. But when food and bacteria get trapped under the flap, the gum can become swollen, painful and infected. This is called pericoronitis.
This guide explains what a gum flap over a wisdom tooth is, why it becomes painful, how it is treated, what you can safely do at home, and when you should see a dentist urgently.
When a wisdom tooth (third molar) only partly breaks through the gum, a small piece of gum can remain over part of the tooth. Dentists call this flap an operculum. It most often affects the lower wisdom teeth.
The space between the flap and the tooth is hard to clean. Food particles and plaque collect there, and bacteria can multiply. When the gum becomes inflamed or infected, the condition is called pericoronitis.
Symptoms of Pericoronitis
- Pain or tenderness at the back of the mouth, often worse when biting
- Swollen, red gum around the wisdom tooth
- A bad taste or bad breath
- Pus or fluid coming from under the gum flap
- Pain that spreads to the jaw, ear or throat
- Difficulty opening your mouth fully
- Pain when swallowing
- Swollen glands under the jaw, and sometimes a fever in more severe cases
Mild cases may only feel tender and slightly swollen, while a severe infection can cause marked swelling and fever. If you are unsure whether your symptoms point to an infection, our guide to infected wisdom tooth symptoms can help.
How Is It Treated?
Treatment depends on how severe the problem is and whether it keeps coming back. Your dentist will examine the area and may take an X-ray to see the position of the tooth.
- Cleaning and irrigation. The dentist cleans under the flap and flushes out trapped debris and bacteria. For mild cases, this along with good home care may be enough.
- Medication. Antibiotics may be prescribed if there is spreading infection, facial swelling or fever. They are not needed in every case. Pain relief can also be advised.
- Removing the flap. A minor procedure to remove the gum flap may be considered in some cases, though the gum can grow back if the tooth stays partly covered.
- Removing the tooth. If the wisdom tooth cannot erupt properly or the problem keeps returning, extraction is usually the long-term solution. Sometimes the opposing upper tooth is removed if it keeps biting the flap. For a breakdown of what to expect, see our wisdom tooth extraction cost guide.
What You Can Do at Home
Home care can ease symptoms while you arrange to see a dentist, but it does not cure the underlying problem.
- Rinse gently with warm salt water several times a day, especially after meals.
- Brush carefully around the area with a soft brush, and keep cleaning the rest of your mouth.
- Use a cold compress on the outside of the cheek if it is swollen.
- Eat soft foods and chew on the other side.
- Take over-the-counter pain relief only as directed on the label, and ask a dentist or pharmacist if you are unsure.
- Do not put aspirin or any medicine directly on the gum, and do not try to cut or lift the flap yourself.
If you later have the tooth removed, follow the advice in our guide to the dos and don’ts after wisdom tooth extraction.
When to See a Dentist Urgently
See a dentist as soon as possible if you have:
- Pain that is getting worse or has lasted more than a day or two
- Swelling of the cheek, face or under the jaw
- Fever
- Pus or a bad taste that does not go away
- Difficulty opening your mouth
Get emergency medical care straight away if you have trouble swallowing or breathing, or if swelling is spreading to your neck or around the eye.
Can a Gum Flap Go Away on Its Own?
A mild flare-up can settle with thorough cleaning and good hygiene, but it tends to come back while the tooth remains partly covered by gum. If it keeps returning, ask your dentist whether removing the flap or the tooth is the better option.
Frequently Asked Questions
What is pericoronitis? Pericoronitis is inflammation or infection of the gum around a tooth that has only partly come through, most often a lower wisdom tooth. It causes pain, swelling and sometimes a bad taste.
What is a gum flap over a molar? It is a small piece of gum that stays over part of a molar that has not fully erupted. It can trap food and bacteria, which is why it sometimes becomes painful.
What are the symptoms of impacted wisdom teeth? Impacted wisdom teeth can cause pain at the back of the jaw, swollen or tender gums, a bad taste, and difficulty opening the mouth. Some impacted teeth cause no symptoms, so an X-ray is the only way to know for sure.
Is a gum flap over a wisdom tooth dangerous? It is often harmless, but if it becomes infected and is left untreated, the infection can spread to nearby areas. Painful or swollen flaps should be checked by a dentist.
How long does a flare-up last? An acute episode often improves within a few days once the area is cleaned and treated, but it can come back if the cause remains.
Do I always need antibiotics? No. Many mild cases are managed by cleaning the area. Your dentist decides whether antibiotics are needed based on the signs of infection.
Will I need my wisdom tooth removed? Not always. If the tooth can come through properly, it may be left alone. If the problem keeps returning or the tooth is impacted, removal is usually recommended.
