Keratocyst Explained

Keratocyst Explained

Keratocyst is the medical term for a keratocystic odontogenic tumor. What is meant by this is an aggressively growing but in most cases benign tumor.

What is a keratocyst?

The keratocyst can usually only be detected by chance during a dental X-ray examination.

A keratocyst is a keratocystic odontogenic tumor (KOT). In medicine, it is also known as an odontogenic primordial cyst. This is a cavity within the jawbone that is lined with keratinized squamous epithelium. See AbbreviationFinder for abbreviations related to KOT.

However, the term keratocyst is now considered obsolete and has been replaced by the term keratocystic odontogenic tumor because it does not correspond to the characteristics of a cyst. It is a unicystic or multicystic intraosseous neoplasia that is usually benign in nature. Instead of a normal tooth, a keratocystic odontogenic tumor forms instead.

Since 2005, the WHO (World Health Organization) has classified developmental keratocysts as head and neck cancer. From a histological point of view, the keratocyst is one of the odontogenic epithelial tumors in which hard substance formation can also be present. In most cases, a keratocystic odontogenic tumor is found in the mandible.

The proportion is 50 to 80 percent. The keratocyst is usually located on the ascending ramus of the lower jaw or on the back molars. The male sex is particularly affected. Among the odontogenic tumors, the keratocyst ranks second. In most cases, a keratocyst occurs between the ages of 10 and 40 or between the ages of 50 and 70.


The keratocyst is one of the odontogenic tumors. These arise in the original tissues of tooth formation. However, the cause of the keratocystic odontogenic tumor has not yet been clearly clarified. There is a presumption that its formation occurs from the remains of the dental ridge.

Multiple keratocystic odontogenic tumors also occur in Gorlin-Goltz syndrome. In addition, basal cell carcinomas form. However, this disease is an exceptional case. The occurrence of the keratocyst is usually solitary.

Symptoms, Ailments & Signs

The growth of a keratocystic odontogenic tumor usually takes place unnoticed, so that it is often only diagnosed incidentally during dental X-ray examinations. The keratocyst presents as a layered keratinizing squamous epithelium in the form of a cavity within the jawbone. Parakeratinization of the epithelium is often present.

The growth pattern of the keratocystic odontogenic tumor is very aggressive, so that mostly satellite cysts form. The cortical bone is destroyed by the keratocyst. This can also affect the adjacent soft tissue. Signs of a keratocystic odontogenic tumor include localized swelling of the jawbone and loosening and shifting of teeth. Pain, on the other hand, occurs only in rare cases.

Diagnosis & course of disease

As already mentioned, the keratocyst can usually only be detected by chance during a dental X-ray examination. X-rays, however, cannot differentiate it from an ameloblastoma . Therefore, for an exact diagnosis, a histological examination of the tumor or a sample after its removal is required.

While smaller keratocystic odontogenic tumors have an oval or round shape, larger keratocysts have a curved edge. Marginal sclerosis is not uncommon. Even after successful surgical removal of the keratocystic odontogenic tumor, it is often to be expected that the keratocyst will reappear.

The recurrence rate is 40 to 60 percent. Even years later, the recurrence of a keratocyst is possible. In rare cases, the keratocystic odontogenic tumor can degenerate and turn into a malignant squamous cell carcinoma. Sometimes an ameloblastoma occurs.


The keratocyst usually develops into a tumor. This spreads extremely quickly, but is benign in most cases. In most cases, treatment is late because the tumor is diagnosed incidentally during check-ups. The person affected does not suffer from any particular complaints or symptoms.

However, there may be limitations and discomfort in the oral cavity. The teeth are often loose and can shift. However, there is no pain. It is not uncommon for inflammation in the mouth to occur, which significantly restricts the patient’s everyday life. It is not uncommon for this tumor to reappear after treatment and must therefore be removed again or treated differently.

Treatment involves surgical removal of the tumor. There are no particular complications. However, the course of the disease is not always positive, so that those affected may develop this tumor again. If removed successfully, life expectancy is usually not reduced. Certain bone defects can be filled with a replacement material.

When should you go to the doctor?

Children and adults should have check-ups with a doctor at regular intervals. Since the keratocyst is often symptom-free and can therefore remain largely unnoticed by those affected for a long time, there is a possibility that it will be diagnosed in the event of an incidental finding during a dental examination. If there are irregularities during the purchase process, difficult conditions when crushing the food in the mouth or a feeling of tightness, a doctor should be consulted.

Disturbances when wearing braces or discrepancies in the use of dentures must be examined and corrected by a dentist. Pain, spontaneous bleeding or inflammation of the gums indicate an existing disease that should be treated medically. If there are deformities of the face, changes in the position of the jaw, restrictions in vocalization or problems with the flow of saliva, a doctor should be consulted.

Discoloration in the mouth, abnormalities in the mucous membranes and hypersensitivity to food and liquids should be discussed with a doctor. If teeth loosen or shift, unusual spaces between the teeth form or if an adult suddenly loses a tooth, a doctor’s visit is necessary. Swelling or growths in the area of ​​the jawbone are considered unusual and indicate irregularities. A doctor should be consulted to avoid deterioration of health.

Treatment & Therapy

The treatment of a keratocystic odontogenic tumor consists of its surgical removal. However, this is not always easy, as it often has satellite or daughter cysts. In this way, small strands of cells, which originate from the keratocyst, grow into the neighboring bones, resulting in the formation of small daughter tumors (metastases).

These daughter tumors cannot be seen with the naked eye. It can therefore happen that they are overlooked even with careful surgical removal of the tumor, which means that the procedure cannot be carried out completely. For this reason, later recurrences are repeated.

In order to ensure the removal of the small microcysts, the surgeon mills out the bone cavity. This leads to a defect that can be filled with autologous bone or bone substitute material. In some patients, the finding is so extensive that it necessitates disruption of bone continuity.

This means that the surgeon not only removes the keratocystic odontogenic tumor, but also the remaining thin bone. This procedure is the only way to avoid a recurrence of the keratocyst. Bone continuity can be restored by using osteosynthesis plates. Alternatively, the insertion of a bone graft is also within the realm of possibility.

The additional use of Carnoy’s solution is also recommended to fix the cyst sac intraoperatively. In this way there is the possibility of reducing the recurrence rate. Follow-up care following surgical removal of the keratocystic odontogenic tumor also plays an important role in therapy. This includes an annual X-ray check over a period of at least five years. But beyond that, a recurrence of a keratocyst can occur.

Outlook & Forecast

The prognosis of the keratocyst is favorable once the affected person has sought treatment. The characteristic of the cyst is characterized by strong growth. If this is not stopped by surgical removal, there is a risk of consequential damage and complications. The teeth or an existing denture are gradually displaced by the growths. The consequences are unwanted changes in the jaw. This leads to disturbances in the speech function and the chewing process.

With medical treatment, the unwanted tissue is completely removed. Although it is a routine procedure, the surgical procedure is associated with the usual risks and side effects. If the removal remains free of complications, the patient’s recovery is usually documented within a few weeks after the removal. Normally, there are no consequences to be expected.

A new keratocyst can form at any time during life. Men belong to the risk group. Even if a cyst grows again, the prognosis remains favorable as soon as it is removed by a doctor.

The prospect of optimal disease progression worsens if treatment is delayed. If tooth misalignments are already present, they must then be corrected in long-term therapy. This has a negative impact on further development and can be associated with impairments.


Measures that serve to prevent a keratocystic odontogenic tumor are not known. The exact causes for the development of a keratocyst have not yet been determined.


In most cases, the follow-up measures for a keratocyst are very limited, so that the person affected should see a doctor very early on in order to avoid further complications or other symptoms. In the worst case, the cancer can continue to spread in the body due to this disease and thus lead to the death of the person concerned.

Therefore, a doctor should be consulted at the first signs and symptoms of the disease in order to prevent its spread. In the case of a keratocyst, those affected are usually dependent on an operation in which the tumor is removed. As a rule, bed rest should be observed after such a procedure, while strenuous or physical activities should be avoided.

The support and help of those affected by their own family also has a positive effect on the further course of the disease and can also prevent depression and other mental disorders. Even after the successful procedure, regular check-ups should be carried out by a doctor. No general prediction can be made about the further course of the disease, although in many cases the life expectancy of the patient is significantly reduced by the keratocyst.

You can do that yourself

Patients suffering from a keratocyst should definitely speak to a doctor. The benign tumor must be diagnosed by a doctor and then surgically removed.

Diet may need to be adjusted before surgery, depending on where the cyst is located and its size. Patients who regularly take medication or suffer from unexplained circulatory system problems should inform the responsible doctor. After the operation rest and bed rest apply. In addition, the surgical wound must be carefully cared for in order to rule out wound healing disorders, infections and other problems. If a cyst forms again, another visit to the doctor is indicated. In general, regular examinations must be carried out after tumor surgery, as there is an increased risk of complications.

In addition to these measures, the cause of the formation of the keratocyst must also be determined if possible. Logopedic treatment is also indicated to alleviate any speech disorders . In the case of permanent problems with speaking, which can occur especially after the removal of larger tumors, further dental treatment measures must be taken.