Short answer: A dental cyst is a fluid-filled cavity surrounded by a membrane that develops in the jawbone, most often at the root tip of a tooth whose nerve tissue has lost its vitality. It usually causes no symptoms and is noticed by chance on an X-ray; as it grows, swelling, a loose tooth or infection may occur. Diagnosis is made with X-rays and CT, and a definitive distinction with tissue examination. Treatment options include root canal treatment, apicoectomy, cyst surgery or extraction.
Hearing at a routine dental checkup that the X-ray shows a dark, round area at the root tip of a tooth and that it "might be a cyst" worries many people. A dental cyst is a cavity surrounded by a membrane and filled with fluid or semi-solid material that develops inside the jawbone, mostly around the root of a tooth or an impacted tooth. It usually grows slowly and causes no symptoms for a long time. In this article we explain how dental cysts form, the symptoms they cause, how they are diagnosed and the treatment options.
What is a dental cyst?
A dental cyst is a fluid-filled sac that develops in the jawbones in connection with the teeth, lined on the inside with a layer of tissue called epithelium. As the cyst grows, it can gradually wear away the surrounding bone and take up space.
There are several types of cysts of dental origin. The most common are:
- Root tip (radicular) cyst: The most common type. It develops at the root tip of a tooth whose nerve tissue has lost its vitality.
- Follicular (dentigerous) cyst: Forms around the crown of an unerupted, impacted tooth, especially impacted wisdom teeth and canines.
- Residual cyst: A cyst left in the bone after a tooth is extracted because the cyst at the root tip was not completely removed.
- Other cysts: There are also rarer developmental cyst types, some of which are more prone to recurrence. Tissue examination is needed to tell these cysts apart.
In this article we focus mainly on root tip cysts, the most common type.
What causes a dental cyst?
Root tip cysts usually form when the tooth's nerve tissue becomes inflamed and loses its vitality because of deep decay, trauma or a fracture, and this inflammation spreads to the bone at the root tip. The process usually progresses slowly and can take years.
The formation process can be summarized as follows:
- Bacteria reach the tooth's nerve tissue because of decay or trauma.
- The nerve tissue becomes inflamed and loses its vitality over time.
- Bacteria and inflammatory products in the root canal leak from the root tip into the bone.
- A chronic inflammatory tissue (granuloma) forms at the root tip.
- Epithelial remnants in this area can multiply under the stimulus of the inflammation and turn into a fluid-filled sac.
Old root canal treatments that were not done adequately or that leak over time can also set the stage for ongoing inflammation at the root tip and cyst development. Follicular cysts, on the other hand, develop when fluid accumulates within the tissue surrounding the crown of an unerupted tooth.
What are the symptoms of a dental cyst?
Dental cysts often cause no symptoms at all and are noticed by chance on routine dental X-rays. When they do start to cause symptoms, they have usually either reached a certain size or become infected.
Possible symptoms include:
- A slowly growing swelling on the gum or jawbone that does not hurt
- Discoloration (darkening) of the affected tooth
- Loose or shifting teeth
- Pain, tenderness and pus discharge when an infection develops
- A recurring pimple-like bump on the gum (fistula)
- In large cysts, especially in the lower jaw, changes in sensation due to thinning of the bone
Because most of these symptoms can also occur with other dental problems, on their own they do not show that there is a cyst. A definitive evaluation is made with an examination and imaging.
How is it diagnosed: X-rays and CT
The first step in diagnosing a dental cyst is an X-ray; in most cases, however, the definitive diagnosis is made by pathological examination of the removed tissue. On an X-ray, a cyst appears as a dark area with well-defined borders inside the bone.
- Periapical and panoramic X-rays: Show the location and size of the lesion and which tooth it is related to.
- Cone beam computed tomography (CBCT): Provides a three-dimensional image. It reveals in detail the true size of the cyst and its relationship to neighboring teeth, the nerve canal and the sinus. It is especially important for large lesions and for surgical planning.
- Tooth vitality tests: Evaluate whether the nerve tissue of the affected tooth is alive. With root tip cysts, the tooth has usually lost its vitality.
- Pathological examination: Examining the surgically removed tissue under a microscope definitively determines the type of cyst.
On an X-ray, a root tip cyst and a granuloma can look very similar. These two conditions can usually be definitively distinguished only by tissue examination; however, the initial approach to treatment is often similar.
Dental cyst treatment: root canal treatment, apicoectomy, extraction
The aim of dental cyst treatment is to eliminate the source of the cyst, clear out the cyst tissue and, whenever possible, preserve the affected tooth. Which method is chosen depends on the type and size of the cyst, the condition of the tooth and its relationship with neighboring structures.
Root canal treatment
For small and medium-sized root tip lesions, the first choice is usually root canal treatment. The infected root canals are cleaned and disinfected and then filled. Once the source of infection is eliminated, some root tip lesions can shrink and heal over time. For teeth that have had root canal treatment before but where the lesion persists, retreatment of the root canal can be considered.
Apicoectomy (root tip surgery)
For root tip lesions that are large or do not heal despite root canal treatment, the gum is opened and the cyst tissue and the very tip of the root are surgically removed. The root tip is usually sealed with a special material. This method allows the tooth to be kept in the mouth.
Cyst surgery
For large cysts, complete removal of the cyst (enucleation) may be planned, or an opening procedure may first be done to shrink the cyst, followed by its removal. Depending on the size of the cyst, these procedures are evaluated by an oral and maxillofacial surgeon.
Tooth extraction
If the tooth is too damaged to be saved or there is not enough bone support left, the tooth is extracted and the cyst tissue is cleared out of the extraction socket. After the extraction, options such as an implant or a bridge can be planned for the missing tooth.
After treatment, the bone can take months to heal. Healing is usually monitored with follow-up X-rays taken at six- to twelve-month intervals.
What happens if a dental cyst is not treated?
Untreated dental cysts often continue to grow, even if slowly, and can damage the surrounding bone, teeth and other structures. The absence of symptoms does not mean the cyst is harmless.
- Progressive bone loss in the jawbone
- Resorption of the roots of neighboring teeth and shifting of the teeth
- The cyst becoming infected and turning into an abscess
- Extension toward the sinus in the upper jaw or toward the nerve canal in the lower jaw
- In very large cysts, weakening of the jawbone and, rarely, a risk of fracture
Small lesions detected early can be treated with much simpler methods. That is why regular dental checkups and X-rays taken when needed are important. For your other questions, you can take a look at our frequently asked questions page.
When should you seek care in Ankara for a suspected dental cyst?
If a lesion has been seen at a root tip on your X-ray, if you have a swelling on your gum that does not go away or recurring pus discharge, or if one of your teeth has darkened over time, it is recommended that you seek an evaluation without delay. At our polyclinic in Park Oran Ofis in Çankaya, we examine the situation with the necessary imaging and explain treatment options that prioritize preserving your tooth; to make an appointment, you can use our contact page.
Frequently asked questions
Does a dental cyst go away on its own?
Dental cysts generally do not go away on their own because the infection that causes them continues. However, some small root tip lesions can heal over time after the source of infection has been eliminated with root canal treatment. Healing is monitored with follow-up X-rays.
Does a tooth with a cyst always have to be extracted?
No, in most cases the priority is to preserve the tooth. The tooth can be kept in the mouth with methods such as root canal treatment or apicoectomy. Extraction comes into consideration if the tooth is severely damaged or there is not enough bone support.
Is a dental cyst dangerous?
The vast majority of dental cysts are benign. However, if left untreated, they can grow and lead to bone loss, damage to neighboring teeth and infection. The exact type is determined by tissue examination.
How long does recovery take after dental cyst surgery?
The soft tissues usually heal within a few weeks. The bone filling in the cavity, however, can take months. Healing is followed with follow-up X-rays taken at set intervals.
