Dentigerous Cyst: Understanding Your Pathology Report

by Jason Wasserman MD PhD FRCPC
May 3, 2026

A dentigerous cyst is a noncancerous, fluid-filled sac that forms around the crown of a tooth that has not yet come through the gum. Because it develops from tissue surrounding a forming tooth, it is sometimes also called a follicular cyst. Dentigerous cysts are the second most common type of odontogenic cyst (a cyst arising from tooth-related tissues), after the radicular cyst. They occur most often in young people between the ages of 10 and 30, are slightly more common in males, and are usually associated with an impacted (stuck) wisdom tooth in the lower jaw.

This article will help you understand the findings in your pathology report — what each term means and why it matters for your care.

What causes a dentigerous cyst?

To understand how a dentigerous cyst forms, it helps to know how a tooth develops. Before a tooth comes through the gum, the crown (the part you can normally see in the mouth) sits inside a small sac of tissue called the dental follicle. This sac surrounds the developing tooth like a tight-fitting balloon. Normally, when the tooth pushes through the gum, the dental follicle disappears. In a dentigerous cyst, fluid begins to build up between the crown of an unerupted tooth and its dental follicle, slowly expanding the sac into a true cyst over months or years.

The exact reason this fluid begins to build up is not fully understood. What is clear is that dentigerous cysts are not caused by poor oral hygiene, infection, or anything the patient did or did not do. They are not contagious and are not inherited in most cases. The most common situation is an impacted lower wisdom tooth, although any unerupted tooth — including upper canines, lower premolars, and supernumerary (extra) teeth — can be involved.

What are the symptoms of a dentigerous cyst?

Many dentigerous cysts cause no symptoms at all and are discovered by chance on a routine dental X-ray, often when an impacted wisdom tooth is being evaluated. When symptoms do develop, they tend to come on slowly:

Swelling — A firm, painless bulge along the jaw, most often in the back of the lower jaw.
Delayed or missing tooth eruption — A tooth that should have come in by a certain age has not appeared. The cyst is sometimes discovered when a parent or dentist investigates the missing tooth.
Tooth displacement — Larger cysts can push the unerupted tooth out of position, sometimes a long way from where it should be.
Loose teeth — Adjacent teeth may become loose if the cyst has eroded the bone supporting their roots.
Pain or tenderness — Usually only when the cyst becomes infected or ruptures.
Numbness — Very large cysts can press on the nerve running through the lower jaw, causing numbness or tingling of the lower lip and chin.

How is the diagnosis made?

The diagnosis is made after a tissue sample is examined under the microscope by a pathologist. A dentigerous cyst is usually first suspected on a dental X-ray, panoramic X-ray, or cone-beam CT, which shows a well-defined dark area surrounding the crown of an unerupted tooth and attached at the neck of the tooth (where the crown meets the root). Imaging alone cannot make the diagnosis with certainty because other lesions — most importantly the odontogenic keratocyst and, less commonly, ameloblastoma — can occur in exactly the same configuration. The cyst is removed by an oral and maxillofacial surgeon, usually together with the unerupted tooth, and sent to the laboratory.

Under the microscope, the pathologist looks for an open space (the cyst cavity) lined by a thin, even layer of stratified squamous epithelium. “Stratified” means the cells are arranged in layers, like bricks in a wall. The lining is typically only two to four cells thick and uniform in appearance. In some areas, the cells may appear cuboidal (box-shaped), columnar (taller than they are wide), or occasionally ciliated, meaning they have small hair-like projections on the surface — a normal finding that reflects the developmental origin of the cyst. Beneath the lining, the wall of the cyst is made of fibrous (scar-like) connective tissue. Importantly, the lining cells of an uncomplicated dentigerous cyst do not show atypia (abnormal cellular changes), which helps confirm that the lesion is benign and is what allows the pathologist to distinguish it from rare cysts that contain tumor or precancerous changes.

What is an inflamed dentigerous cyst?

A dentigerous cyst is described as inflamed when inflammatory cells are present within the cyst wall. Inflammation often occurs when the cyst becomes infected or ruptures, particularly in cysts associated with a partially erupted tooth, where bacteria from the mouth can reach the cyst cavity. Under the microscope, the pathologist may see inflammatory cells such as lymphocytes, histiocytes, and multinucleated giant cells, along with cholesterol clefts — slit-like spaces left behind by cholesterol crystals that have leaked from broken-down cells. Inflammation can make the cyst lining thicker, more irregular, and harder to recognize, but it does not mean the cyst has become cancerous. It does, however, sometimes make the microscopic distinction from a radicular cyst more difficult, in which case the X-ray location of the cyst (around the crown of an unerupted tooth, rather than at the tip of a root) is the deciding clue.

Eruption cyst — a related diagnosis

An eruption cyst is a closely related lesion that occurs in the soft tissue of the gum, immediately above an erupting tooth. It is most often seen in young children when a baby tooth or a permanent molar is just about to come through the gum. The cyst appears as a soft, bluish swelling on the gum and usually resolves on its own as the tooth erupts. Under the microscope, an eruption cyst looks similar to a dentigerous cyst — the difference is its location in the gum rather than within the bone of the jaw.

What is the prognosis?

The outlook for a dentigerous cyst is excellent. It is benign and does not turn into cancer. Once the cyst and the associated unerupted tooth are removed, the bone almost always fills in completely over the following 6 to 12 months, and the area returns to normal on follow-up X-rays. Recurrence is uncommon when the cyst has been completely removed.

Although extremely rare, it is recognized that an ameloblastoma or, even less commonly, a squamous cell carcinoma can arise from the lining of a long-standing dentigerous cyst. This is one of the reasons pathologists carefully examine the entire cyst wall under the microscope rather than relying on a small sample. If the report describes only an uncomplicated dentigerous cyst with no atypia and no tumor, no further treatment beyond surgery is needed.

What happens after the diagnosis?

Treatment of a dentigerous cyst is led by an oral and maxillofacial surgeon, often working with a general dentist or orthodontist for any later dental work. The choice of operation depends on the cyst’s size, location, the patient’s age, and whether the involved tooth can be saved.

Enucleation with extraction — The most common approach. The cyst and the impacted tooth are removed in a single operation. The empty socket fills in with new bone over several months.
Marsupialization (decompression) — Used for very large cysts and especially in younger patients, where preserving the involved tooth is desirable. The cyst is opened to the mouth and allowed to slowly shrink over several months. Once the cyst has decreased in size, the involved tooth often erupts naturally or can be brought into position with orthodontic treatment, and any residual cyst can then be enucleated.
Enucleation with tooth preservation — Occasionally possible for small cysts when the involved tooth is in a position to erupt and is worth saving.

Follow-up X-rays are typically obtained at 6 and 12 months to confirm bone healing. Long-term follow-up beyond that is usually not needed once the cyst is gone and the bone has filled in. If the involved tooth had to be removed, the missing tooth can later be replaced with an implant, bridge, or — in younger patients — by orthodontic movement of a neighboring tooth into the gap.

Questions to ask your doctor

Which tooth was the cyst associated with, and was that tooth removed?
Was the entire cyst removed during the operation?
Did the pathology report show any unusual features, such as atypia, ameloblastoma, or another tumor in the cyst lining?
How extensive was the bone damage, and how long will it take to heal?
What is the chance the cyst could come back?
If the involved tooth was preserved, will it erupt on its own or will I need orthodontic treatment to bring it into position?
If the tooth could not be saved, what are my options for replacing it?
What is the schedule for follow-up X-rays?
Are there any other unerupted teeth that should be monitored?
Will I have any lasting numbness or changes in my bite?