Wisdom tooth infections - Pericoronitis.

- Why does the infection occur? | How is it treated? | Incidence rates - Statistics | If you've experienced pericoronitis, does your tooth need to be extracted?

1) What is pericoronitis?

"Pericoronitis" refers to an acute bacterial infection located in the soft tissues that surround the crown portion of a partially erupted tooth. Most cases involve wisdom teeth.

  • The "crown" of a tooth is its non-root portion. This is the part of a normally positioned tooth that is visible above the gum line.
  • A "partially erupted tooth" is one whose crown portion has only partway penetrated through the gum tissue (see animation).
  • This partially-erupted positioning may just be temporary because the tooth is still in the process of coming in.

    Or it may be permanent, as in the case of a partially-erupted impacted tooth (a tooth's whose eruption progress is blocked and therefore can proceed no further).

Animation showing a partially erupted wisdom tooth.

Where does the term "pericoronitis" come from?

This word breaks down as follows:

  • "Peri" means "around."
  • The "coron" portion of the word refers to the "crown" of the tooth.
  • The suffix "itis" refers to the presence of inflammation.

Altogether, the term pericoronitis refers to the presence of inflammation in the tissues that surround a tooth due to an infection associated with its (submerged in the gums) crown portion.


2) Details about Pericoronitis. -

a) What causes it? - It's caused by bacteria.

The underlying process/problem associated with pericoronitis is an infection, typically caused by ordinary oral bacteria (like those routinely found in the mouth).

Graphic showing the follicular sac surrounding a partially erupted wisdom tooth.

It's the gum relationship around a partially-erupted tooth that allows pericoronitis to occur.

The scenario involved is one where bacteria have colonized the space (a sac) that exists between the crown portion of the tooth and its surrounding gum tissue.

  • The sac is formally termed a "follicular sac," and its tissues played an important role in the formation of the wisdom tooth.
  • Once the tip of the wisdom tooth has penetrated through the surface of the gums, the integrity of the sac is lost and bacteria are able to seep into it.
  • Since the area within the sac is impossible to clean, a bacterial colony (dental plaque) will form within it.

The bacterial colony may have (and probably has) been present for an indefinite period of time. However, no symptoms are noticed because the person's body defense mechanism (immune system) has been able to keep it in check.

However, if some type of event is able to tip this balance (illness, gum tissue trauma, increased numbers of bacteria or a better food supply for them), an active phase of infection (redness, tenderness, pain, swelling) can be triggered.

How often will pericoronitis form? - Transient vs. persistent episodes.

As long as a tooth remains partially erupted and is impossible to effectively clean, a person may experience repeated episodes of pericoronitis with that tooth.

  • Transient - In cases where the tooth is in the process of coming in, the problem should just be a transitory one. Once the crown of the tooth fully clears the gum line, it should be possible to properly clean (brush and floss). If so, no more episodes of infection will occur.
  • Persistent - In cases where the tooth is both partially erupted and impacted (meaning no further progress through the gum tissue will occur), it's common, and even likely, that the person will experience repeated infections.

Section references - Hupp, Koerner, Wray

b) Concerns with pericoronitis - The spread of infection.

A problem with pericoronitis is that the infection that is initially just localized around the culprit tooth can spread throughout neighboring tissues, possibly spectacularly so.

Normal conditions.

As mentioned above, since the space around a partially-erupted tooth can't be cleansed, it always harbors a bacterial colony.

And as those bacteria create waste products, their debris simply vents off into the mouth through the same opening into the sac that the bacteria initially entered in through.

Animation illustrating the spread of pericoronitis to associated tissues.

What starts as a localized infection around the tooth can spread into associated tissues.

Active phases.

During periods when the bacterial colony becomes active, the person's body will respond by infiltrating the area with compounds and white blood cells to combat the infection.

And as that occurs the tissues surrounding the tooth will swell and begin to press against the tooth, ultimately sealing the vent that previously existed.

As a result, the greater number of bacteria and debris (pus) now being created by the infection no longer have a way to vent off.

These items will remain locked in the area's tissues, and cause further swelling. And if a pathway can be found, these items will force themselves into associated structures too, like a person's face or neck.

Pericoronitis around a lower wisdom tooth.

The initial formation of infection around a lower partially erupted wisdom tooth.

3) What are the signs and symptoms of having pericoronitis?

The signs of pericoronitis include:

  • Redness, tenderness and swelling in the gum tissue immediately surrounding the wisdom tooth.
  • The lymph nodes that service the area of the swelling (like those under the jaw and in the neck) may be enlarged.
  • With some cases, the swelling may extend into the face and neck. It may make it difficult for the person to open their mouth (trismus) or swallow.
  • The person may also experience moderate to severe pain, an unpleasant mouth odor, and/or a bad taste coming from the infected area.
Some cases can be life-threatening.

Related to the anatomy of the region, it's possible for an infection located in the soft tissues surrounding a lower wisdom tooth to spread rapidly and extensively into the region of the throat and neck.

If so, the extended tissues may interfere with the person's ability to breathe and swallow, thus causing a potentially life-threatening situation. These cases may require hospitalization and possibly surgery to drain the infection.

Especially for this reason, if you notice the signs and symptoms of developing pericoronitis, you should advise your dentist sooner rather than later.


5) How is pericoronitis treated?

This condition needs to be evaluated and treated by your dentist. In most cases they will:

  • Reduce the bacterial load in the infected area (remove accumulated debris, establish the drainage of pus) by way of debriding (scraping) and/or irrigating (flushing out) the under-the-gum-line spaces that surround the tooth.

    (To increase effectiveness, a solution that has antibacterial properties, such as hydrogen peroxide or the prescription mouth rinse chlorhexidine, may be chosen as the irrigating solution.)

  • The dentist may then maintain the drainage pathway they've established by way of propping open an entrance into the space that's been cleansed by packing gauze.

    (Gauze impregnated with iodoform, and antibacterial agent, is often chosen for this function.)

  • Prescribe an antibacterial oral rinse for home use (frequently chlorhexidine) that can be used several times a day to clean the infected area and reduce its bacterial load.

    (Short of this, saline solution [1/2 teaspoon of table salt in 1 cup of water], or even just water, might be used.)

  • If access exists, show you methods by which you can flush out the space between the tooth and gum tissue (the area that harbors the bacteria causing the infection) using an "irrigating" (blunt-tipped) syringe.
  • If beyond experiencing localized swelling and pain the patient also displays signs of facial swelling, trismus (limited range of motion of the jaw) or low-grade fever, the dentist will consider administering an antibiotic.

    (Notes: It usually takes on the order of 24 hours for oral antibiotics to begin to have a noticeable effect.

    Especially in light of current concepts regarding the (over) use of antibiotics, for mild cases the other steps mentioned in this list are usually satisfactory and no antibiotic is utilized.)

A dental x-ray showing where pericoronitis occurs.

X-ray diagram showing where the infection initiates.

Definitive clinical treatment for pericoronitis.

Before any type of definitive treatment can be performed for the tooth, its infection must subside to subacute levels (be substantially resolved).

The time period needed for this will need to be determined by the dentist treating the case but usually lies on the order of no sooner than 2 to 7 days after the patient's initial care (establishing drainage, starting oral antibiotics, performing rinsing and irrigation).

  • In cases where a decision is made to extract the wisdom tooth, the procedure should be scheduled.
  • If a decision is made to retain the tooth, the dentist may feel that trimming overlying gum tissue from around it (an operculectomy) may be indicated. Or that trimming the cusps of the opposing tooth (so they are less likely to traumatize/bite this tissue) is the solution needed.
  • With other cases, a wait-and-see approach may make an appropriate plan.

4) Statistics - How frequently do people experience pericoronitis?

  • Friedman's review of published literature concluded that the incidence rate for a person experiencing pericoronitis in association with a wisdom tooth falls along the lines of 6 to 10%.
  • Research frequently cites pericoronitis as being the most common reason for wisdom tooth removal. Some studies place this number as high as 40 to 59% of cases. (Faculty)

As we explain below, experiencing a single episode of pericoronitis does not necessarily constitute a valid reason to extract a wisdom tooth. The tooth's outlook in regard to its ability to ultimately fully erupt (clear the gum line) should be the basis on which the decision is made.

Section references - Friedman, Faculty

If you experience pericoronitis, does your tooth need to be pulled?

a) All teeth are just partially erupted at some point.

Just like every other tooth that comes in, even wisdom teeth that eventually fully erupt into normal and proper alignment go through a transitional period where they are only "partially erupted."

That's because it takes some time for a tooth to fully penetrate through the gums and achieve its final positioning. And during that time frame when the wisdom tooth is only partway through the gums, it is at risk for developing pericoronitis.

b) Partially erupted teeth are not necessarily impacted teeth.

When a dentist evaluates a patient that has pericoronitis they need to determine whether the tooth's partially erupted status is simply a transitory phase of the normal eruption process. Or if it's instead impacted (meaning the tooth will always remain partially erupted).

In the first case, the dentist's approach will be to actively manage the patient's current condition (prescribe antibiotics, irrigate the area, etc...). It's expected then, over time as the tooth erupts more fully, that its potential for additional flareups will diminish.

In the latter case, if the impacted tooth's positioning is not expected to resolve (come into normal position) and therefore it will always remain at risk for recurring infections, the most frequent treatment solution is extraction.


c) Operculectomy.

Some wisdom teeth that experience pericoronitis may have a relatively normal positioning in the jawbone but due to their circumstances the gum tissue that surrounds them is too "tall" or covers over them substantially.

If so, it may be possible for the dentist to resolve this issue by way of performing a minor surgical procedure termed an operculectomy. During this procedure, the unwanted gum tissue is trimmed away, with the outcome being that the tooth can now be cleansed thoroughly.

The suitability of performing this procedure will need to be evaluated in light of why the gum condition exists in the first place. If performed in situations where not appropriate, the tissue will simply tend to grow back.

Reference sources - Primary sources for this entire page: Hupp, Wray, Koerner



Sore gums

There are times when I can see just a part of my wisdom molar. From time to time it seems to disappear and the gums in that area get really sore. I'm afraid of having a tooth pulled.


You're on the right page. From your description it would seem that what you have noticed is repeated episodes of pericoronitis.

Your tooth "disappears" due to the swelling of the gum tissue around it. The pain and swelling are all symptoms of an infection surrounding your tooth because you cannot clean it properly.

You can only see a part of your tooth because it is just "partially" erupted. And it's because your tooth has not fully penetrated your gums that you can not clean it (remove bacterial accumulation from around it) effectively.

The only question is whether the tooth will finally erupt (come through) the gums properly or not (is in it's impacted).

If the tooth is impacted (meaning is stuck in that position), you'll continue to experience episodes of pericoronits. (Everything we have mentioned here is explained in greater detail above on this page.)

The solution is to have the tooth taken out. The process of tooth removal really isn't all that bad, or painful. For some people, the use of sedation medication for their procedure can place them more at ease.


My wisdom tooth looks fully out. However the gum surrounding it is white and red, theres a space between toorh and gum and it smells. The first time i ever felt discomfort was quite young and for years ive had "appearances" . I thought it was all over but i know somethings wrong. I've also been experiencing bleeding gums and i tried my hardest to treat it without seeing a doctor. The bleeding got less but then i began to notice my wisdom tooth. Now its very sore and frankly very gross (the tooths not rotten but theres quite a deep gap in my gum and i cannot clean it :( ).
I just want to tooth pulled out and i dont want to have to wait a week :(


We agree, what you describe does seem to correlate with the common set of symptoms associated with recurring episodes of pericoronitis. You also mention that this has been going on for some years.

As you seem to already have planned, this matter does need to be pursued with your dentist because a wisdom tooth that can't be cleansed properly potentially does place neighboring teeth at risk for damage or loss related to tooth decay and/or gum disease.

As far as the timing of your extraction, only your dentist can determine if the level of infection that currently exists is likely to complicate your procedure and therefore must be brought under control first.

Possibly your scheduling with your dentist will just happen to coincide with periods when your tooth's condition is comparatively quiet. If so, that might speed things along. Good luck.

Swelling around wisdom tooth

I'm 43, I have one wisdom tooth left & it was halfway under the gum & halfway out, kind of slanted. I've had no problems with that tooth until the last couple of years. The tooth has been coming out in pieces so there was just a shell. It has come down to the remainder of the tooth which is barely a rigid area above the gum & nothing but a hole in the middle that catches all kinds of food but I can take a sip of a drink & keep it in my mouth & suck & whatever food is in there will come right out. The last week or 2 I've noticed an edge of the tooth is nothing but swollen gum & it's been sore. Just the past couple of days I've felt that there's something (not food) in the hole of the tooth & it's really sore. I got a flashlight & a dental mirror & looked back there where that hole is in the shell of that tooth & I can see something white in that hole. It won't come out. I'm starting to think it's my gums. Is there something I can do at home to help the pain & swelling until I can get an appointment to see a dentist? Thank you!


What you seem to describe is an impacted, partially erupted wisdom tooth ("halfway under the gum & halfway out, kind of slanted") ... (like the graphics on this page illustrate)

... That also has a large carious lesion (cavity) ... ("The tooth has been coming out in pieces so there was just a shell").

We won't wager a guess at precisely what you see or what is going on but it seems likely that an infection in the area of the tooth is involved. If so, the basis for it might be either pericoronits (due to the poor positioning of the tooth) or an endodontic problem (the nerve has been affected by the advancing decay).

If either is the problem, at this stage, for this type of situation, a common scenario would be one where the patient's dentist places them oral antibiotics (so to lower the level of the infection) and then about a week later extract the tooth. If needed, pain relievers are used to control the patient's discomfort in the mean time.

If you are a current patient of record with a dentist (have an active chart at their office), possibly after a verbal evaluation over the phone they might feel it's appropriate as emergency treatment for them to prescribe these items for you by phoning the prescription into a pharmacy prior to actually seeing you in their office.

In lieu of that, and following with the same hypothesis about your tooth as above, being seen at an urgent care/walk in facility would probably lead to the same prescriptions. Of course, treatment by your dentist would still be needed.

Short of that, if what you are experiencing is pericoronitis, possibly gently rinsing the area with water might dislodge debris, carry away bacteria and help to establish drainage so the infection will subside more quickly. But in reality, the benefit of that would probably be marginal.

Wisdpom tooth cutting back of my cheek

I am 25. Last year, I got a wisdom tooth on the upper left side. It is partially erupted. Never had a problem cleaning it. But day before yesterday when I woke up in the morning I felt a slight pain at the back side of my left cheek. On closer inspection, I noticed that it was caused by the wisdom tooth slicing across the cheek. It made it difficult (but not so much) for me to completely open my mouth. Yesterday I rinsed my mouth twice with salt water. The pain seems to be fading now. Should I be worried about my tooth? Will it cause trouble in future if I don't get rid of it?


You simply need an evaluation by a dentist. They'll advise you as to what should be done with your tooth and if your current infection needs any management by them.

As far as the tooth's outlook, as discussed above, a big question is whether the tooth's partially erupted status is permanent or transitory. If it's expected that the tooth will never fully come into proper position, despite your comment "Never had a problem cleaning it.", as the illustrations on this page show, it's not really possible to thoroughly clean a partially erupted tooth, so there's always the potential that the same problem will occur again at some point.

While we're not entirely clear on this statement: "caused by the wisdom tooth slicing across the cheek." It's not uncommon for an upper wisdom tooth to come in at an (improper) angle where its cusps scrape and irritate the patient's cheek. If a tooth is both partially erupted and has a poor alignment, extracting the tooth is a common solution but it will take your dentist's evaluation to decide if that is indicated.

Wisdom tooth

My wisdom tooth is fully grown above gums but rotten and hollow and half broken off. It recently tonight started hurting severely and draining a white chunky stubstance. I used a whole tube of maximum strength orajel trying to aleiviate the pain. And now the tooth hole is filled with the white substance. I plan on going to the dentist as soon as possible. What do you think?


At this stage, it seems likely that you have an active infection associated with your tooth. Quite possibly rather than originating in the tissues that surround your tooth (pericoronitis), the infection's origin is instead inside the tooth's nerve space (related to the very advanced decay that you describe).

Pus coming from an infection is white in color, however we are less familiar with it being described as "chunky."

The product you mention contains benzocaine, a topical anesthetic. Topicals are typically only effective in numbing up the surface of the gums. If you have an infection (whatever the location), that's probably not going to provide a lot of relief.

Your solution lies with your dentist. One would guess that an extraction is in your future. Your dentist may need to place you on antibiotics before that can be done. You should describe your situation to them when you contact them. If they feel antibiotics are indicated, possibly they can phone your pharmacy so you can get started with them as soon as possible.

Wisdom tooth infection

My wisdom tooth broke recently and I saw a dentist about it. Said I will need a surgical extraction to remove it but put me antibiotics first. The infection cleared up but I lost my job and health insurance so I was unable to have the extraction done yet. Now the back of my tongue and in my throat have started turning white. Is this a serious indication for something? It really startled me when I noticed it. But no dentist I’ve been to will accept me without any insurance.


You don't really mention the time frame involved between taking the antibiotic and the appearance of the white coloration you notice. We're assuming they're somewhat coincident.

It's possible that what you see is a fungal overgrowth termed Candidiasis (oral thrush). Sometimes taking a medication like an antibiotic disturbs the normal balance of microorganisms in your mouth, and this fungus becomes the dominant organism in the area. You should find a number of pictures on the web to compare you situation to.

Removal of impacted Wisdom tooth of person 74yrsold

4 months ago I had an upper left molar removed. When it was removed a little bit of the wisdom tooth peeked through. Now, the gum has covered a lot of the area but the wisdom tooth shows a bit more.

The dentist took x-rays and recommended removal. I know. There is always the possibility of eventual gum disease but right now after 4 months there is no pain and I try after eating anything to clean the area and never chew on that side anything hard.

Is it sensible to just wait and see in case any bacteria create future infection? Should I wait until infection develops to see him again?

* Comment notes.


Your biggest potential for a problem with the tooth probably lies with the potential for pericoronitis (the situation discussed on this page). And then as you state, the development of complications with gum disease could be a future issue too.

It's not exactly clear from your comment which tooth has been extracted. But if it was the one immediately in front of your wisdom tooth (the one that blocked it from coming in), now that it's gone the wisdom tooth might erupt (thus resolving your problem configuration that allows pericoronitis to occur).

A wait-and-see approach might be considered reasonable for this type of situation but that needs to be discussed with your dentist since only they know your case and the precise configuration involved.

Gum Flap

My wisdom tooth is coming out at the correct angle but is partially erupted, therefore leaving part of the gum hanging over the back of the tooth. I had one bad episode where the gum and my face swelled up due to infection, a few weeks ago I noticed pain in the area again so went to the dentist who cleaned out the area which then managed to resolve over the next few days, though I'm still getting some pus coming out from the gum that brings a bad taste so I went back to the dentist who gave me antibiotics, which didn't resolve the issue so I went back again and they gave me some other ones which again, don't seem to be resolving the problem.. I have no swelling or pain in the area just the thought of pus and the bad taste isn't something I want to continue with


For the most part, oral antibiotics are taken for their systemic effect (fighting infection that has established itself within the confines of your tissues, like the swelling you experienced).

The persistent pus you notice probably comes from a focus of bacteria external to your body's tissues, specifically in the crevice of space that exists underneath the tissue flap and around your tooth. (Some kinds of systemic antibiotics do wind up being excreted by the body into the fluids that leach into these kinds of areas, and therefore they may have a benefit, but not all are.)

Like mentioned above, with teeth in transition like yours, the person's dentist may decide that the area needs to be "irrigated" (gently flushed out) regularly using a blunt-tipped irrigating syringe so bacteria don't have a chance to accumulate in the space. (You'll have to seek the advice of your dentist on this matter.)

This extra cleaning process is continued until the tooth has fully erupted and the flap of skin and its harboring/trapping debris is no longer an issue.

* Comments marked with an asterisk have either been edited for brevity/clarity, or have been moved to a page that's better aligned with their subject matter, or both. If relocated, the comment and its associated replies retain their original datestamps, which may affect the chronology of the page's comments section.

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