Dental cysts: symptoms, diagnosis and treatment

A dental cyst is a cavity within the tissues, often in the jawbone, that contains fluid or other material and usually has a lining. Some form near the root of an infected tooth; others develop in a different way, including around an unerupted tooth.

A cyst may be found during an examination or on an X-ray taken for another reason. It can be present without pain. The next step is to establish what the finding is and whether it needs treatment or monitoring.

Why do cysts develop?

An inflammatory cyst can be associated with infection in a tooth whose pulp has died. The pulp is the soft tissue inside the tooth. Decay or an injury may be part of that history.

Other cysts relate to tooth development rather than an infection. Not every cyst results from poor cleaning or previous dental treatment, and finding one after root canal treatment does not, on its own, prove that the treatment was performed incorrectly.

Symptoms and assessment

Some cysts cause no symptoms. Others may be associated with swelling, tenderness, drainage, changes in tooth position or a loose tooth. These findings can also have other causes; a darkened tooth or pain is not enough to diagnose a cyst.

Your dentist will examine the area, assess nearby teeth and review suitable imaging. They may refer you to an oral surgeon or another specialist. An X-ray can show the location and extent of a change in the bone, but it cannot always distinguish a cyst from other lesions.

A tissue sample may be needed to establish the diagnosis. If tissue is removed during surgery, laboratory examination can help determine its type and guide follow-up. Ask what the working diagnosis is and when you will receive any test results.

How is a dental cyst treated?

The plan depends on the diagnosis, size and position of the cyst, nearby structures and the condition of the teeth. There is no single sequence of treatments that everyone must go through.

If the problem is linked to an infected tooth that can be retained, root canal treatment or repeat root canal treatment may be considered. Treating the infection can allow the area to heal, but follow-up is needed to assess the response. A filling alone does not treat an infection within the root canal.

Surgery may involve removing the cyst and its lining, rather than simply emptying its contents. For some larger cysts, the surgeon may instead plan an opening or a drain to reduce their size before further treatment. They should explain how this will be cared for and monitored.

Root-end surgery, also called an apicectomy, treats selected problems around the tip of a tooth root. It may be considered when ordinary root canal treatment or retreatment is unsuitable or has not resolved the problem. It is not a universal last step for every cyst. Sometimes an associated tooth cannot be saved and extraction is discussed.

The team should explain the expected benefit, alternatives and risks, including those related to nearby nerves or other structures. Read more about root canal treatment.

Follow-up and when to seek help

Attend the reviews recommended for your diagnosis, even if the area no longer hurts. Healing may need to be checked with imaging, and some cysts can recur. If monitoring is chosen, make sure you know when the next assessment is due and which changes to report.

Seek urgent dental advice for increasing swelling, severe pain, pus or a fever. Contact NHS 111 if you cannot get urgent dental care. Call 999 or go to A&E for difficulty breathing, swallowing or speaking, swelling affecting the eye or vision, or marked difficulty opening the mouth.

Good oral care and timely treatment of dental problems can reduce some infection-related risks, but they cannot prevent every type of cyst. Check-up intervals should be based on your needs. Contact us if you have a new swelling or need an assessment of a finding on an X-ray.