Tags Posts tagged with "Cysts"


Keratocystic Odontogenic Tumor

I’ve gotten a few questions about odontogenic keratocysts lately, so I figured it would be good to write an article detailing what we know about them.

Before I get started, let me say that in 2005, the World Health Organization actually changed the name of odontogenic keratocyst to keratocystic odontogenic tumor.  It had been known as odontogenic keratocyst for nearly 50 years, since its discovery in 1956.  In honor of that tradition, and since most people still refer to it as an odontogenic keratocyst, I’m going to call it odontogenic keratocyst throughout this article.

For your viewing pleasure, here’s a photo of what an odontogenic keratocyst looks like at the cellular level — Thanks to Nephron for the photo.

Odontogenic Keratocyst

If you’re in the mood to see a picture of an odontogenic keratocyst after it has been cut out of someone’s jaw as well as the tooth, take a look at this case report and scroll down to the images.

What is an Odontogenic Keratocyst?

An odontogenic keratocyst is a benign tumor of the jaw (that’s why the new name, keratocystic odontogenic tumor makes sense.)   It is associated with an unerupted tooth about one-third of the time.

One of the reasons dentists recommend extracting wisdom teeth is that they can stay in the jaw and make it more likely that you’ll get problems such as an odontogenic keratocyst.

Odontogenic keratocysts grow inside your jaw bone, so you can’t see them.  They usually don’t cause your jaw to expand, they simply eat away at your bone.  They are able to move your teeth and even eat away at them.

What Causes an Odontogenic Keratocyst?

It’s not exactly known what causes an odontogenic keratocyst, but we know that it comes from the dental lamina.  The dental lamina is just a fancy name for the tissue that helps to form a developing tooth.  After the tooth is developed, this tissue is normally dissolved.  Sometimes the tissue sticks around and can give rise to an odontogenic keratocyst years later.

Where Do Odontogenic Keratocysts Occur?

They most often occur in the lower jaw in the area of the wisdom teeth. It has been reported that 60-80% of odontogenic keratocysts occur in the lower jaw. Approximately 1/3 of the time, odontogenic keratocysts are found in the upper jaw in the wisdom tooth area or the canine area.

Who Can Get an Odontogenic Keratocyst?

People of almost any age can get an odontogenic keratocyst.  Odontogenic keratocysts are more common in males than females. Some sources say that the peak age ranges from the teenage years to the early 20’s.  Another source says that 60% of all cases are diagnosed in people between the ages of 10-40.

How Common are Odontogenic Keratocysts?

I literally looked at about ten oral pathology textbooks in the library today trying to answer this question (posed by Stephen in this comment.)  The best I can do is to say that odontogenic keratocysts are rare and that they make up about 5 to 15% of all odontogenic cysts that are reported.

How is an Odontogenic Keratocyst Detected or Diagnosed?

An odontogenic keratocyst can be detected by routine dental x-rays.

Smaller odontogenic keratocysts usually don’t have any symptoms associated with them and are only discovered by taking routine x-rays. This is why it is important to have periodic x-rays taken at your dental checkup.

Find out how often you should get dental x-rays taken.

If an odontogenic keratocyst goes undetected and gets big it may burst, leaking keratin into the surrounding area in your jaw and causing lots of pain and swelling.

Treatment of an Odontogenic Keratocyst

Although there are promising new techniques to treat an odontogenic keratocyst, the most common method of treatment is simply going into the jawbone and removing the odontogenic keratocyst.

Recurrence of Odontogenic Keratocysts

It is estimated that about 30% of people with odontogenic keratocysts that have had them removed will get them again.  Most of them will recur within 5 years, but they can recur 10 or more years after they were oroginally removed.

Because of this is is extremely important to routinely follow-up with your dentist or oral surgeon so that they can take x-rays to ensure that it has not recurred.

It seems that odontogenic keratocysts come back for one of two reasons:

1 – The original odontogenic keratocyst wasn’t completely removed, and fragments that were left behind have started growing again to create a new odontogenic keratocyst.
2 – An entirely new odontogenic keratocyst has developed.

Neville & Damm’s oral pathology textbook states, “Odontogenic keratocysts often tend to recur after treatment.  Whether this is due to fragments of the original cyst that were not removed at the time of the operation tr to a “new” cyst that has developed from dental lamina rests in the general area of the original cyst cannot be determined with certainty.”

What Makes You More Likely to Get Recurrence of an Odontogenic Keratocyst?

So let’s say that you’ve had your odontogenic keratocyst removed and then it came back.  Is there a way to find out if it was the surgeon didn’t remove the whole cyst or whether a new one formed?

This thousand dollar (really) oral pathology text states, “When recurrences develop, those associated with the surgeon leaving residual cyst lining in bone become radiographically apparent within 18 months.”

If you don’t get a new odontogenic keratocyst within 18 months of having one removed, you can be fairly confident that it was fully removed by your surgeon, but there is still a possibility that you’ll get another one simply due to a new odontogenic keratocyst developing.

Another thing that affects the likelihood of recurrence is whether or not the cyst is removed in one whole piece.  If the cyst can be removed in one piece, with the lining of the cyst in tact, there is a much lower chance of recurrence.  On the other hand, if your surgeon has to remove the odontogenic keratocyst in several pieces, it is more likely to recur.


This article was on a more technical subject in dentistry.  My goal is to write so that people can easily understand even these complex topics.  If you have any questions, please let me know in the comments section below.

Also, if you have or have had an odontogenic keratocyst, feel free to share your experience in the comments as well so that others who are going through a similar situation can benefit.  Thanks for reading!