Dental Cyst: Signs, Symptoms, Causes and Removal Options

Dental cysts are the most common type of cyst found in the jaw, though they are far less common than problems such as tooth decay or gum disease. Radicular cysts, which form at the root of a tooth whose nerve has died, account for most cases. Dentigerous cysts, which form around a tooth that has not erupted through the gum, are the next most frequent. Most are found by chance on a routine dental X-ray, as they grow slowly and painlessly and rarely cause symptoms early on.

Dental cysts grow slowly, enlarging over months or years rather than weeks. A radicular cyst, which forms at the root of a dead tooth, expands gradually in one spot, while an odontogenic keratocyst spreads further along the jaw in the same time. An infected cyst is the exception and may swell within days. Slow growth is the reason so many cysts cause no symptoms until they are large enough to show as a visible swelling.

A dental cyst usually feels firm rather than soft, as the fluid inside is enclosed within a wall of tissue. A cyst within the jawbone often feels hard, because the layer of bone stretched over it is what can be felt from the outside. Once that bone has thinned, the area may feel springy or crackle slightly under pressure. A cyst in the gum tends to feel smoother and more rubbery, though texture alone cannot distinguish a cyst from other lumps.

Bad breath can be caused by a dental cyst, though usually only once the cyst has become infected. An uninfected cyst has no opening into the mouth, so its contents cannot escape and it usually produces no odour. Infection introduces bacteria that release sulphur compounds, and where the cyst drains into the mouth it may cause a bad taste as well as a smell. The tooth that caused the cyst may also be decayed or dying, adding an odour of its own. Persistent bad breath alongside a swelling suggests infection rather than poor dental hygiene.

A dental cyst can return after removal, and the likelihood depends on the type of cyst and whether its lining was removed completely. The lining is the thin layer of cells forming the cyst wall, which produces the fluid inside. Radicular cysts seldom return once both the cyst and the affected tooth have been treated. Odontogenic keratocysts return more often, as their lining is thin and any fragment left behind may regrow. For these, the oral surgeon also scrapes the bony walls after removal, a step called curettage, which may reduce the risk of the cyst returning.

An oral fibroma is not the same as a dental cyst, though both may appear as a lump in the mouth. A cyst is an enclosed sac containing fluid, forming in the jawbone around a tooth root or an unerupted tooth. A fibroma is a solid lump of fibrous tissue in the soft lining of the mouth, caused by repeated rubbing such as cheek biting or a denture edge. Both are benign, and an examination with an X-ray can help to differentiate them.

A dental cyst is usually only removed through surgery, and the tooth that caused it is treated at the same time, as removing one without the other may allow the cyst to return. The typical approach is enucleation, which means lifting out the whole cyst together with its wall in one piece. Very large cysts may be drained first and left open to shrink, a procedure called marsupialisation. If you have a lump in your jaw or gum, it is advisable to consult a dentist, who can examine it and recommend suitable treatment.

Most dental cysts are benign and slow-growing, so they are rarely dangerous in themselves, but they are not harmless if left untreated. Continued growth can thin the jawbone, loosen nearby teeth and wear away the roots of healthy ones. A large cyst in the lower jaw may press on the nerve and cause numbness in the lip or chin, while one in the upper jaw may extend into the sinus. Cancerous change is rare, which is why every removed cyst is examined in a laboratory.

Very few dental cysts resolve without treatment. Two exceptions exist: dental lamina cysts in newborns, which disappear within weeks, and small radicular cysts, which may shrink after the affected tooth has root canal treatment. Other types persist, as the cyst wall continues to produce fluid and slowly enlarges the cavity it occupies in the bone. Delaying treatment generally allows the cyst to grow, which may make the eventual operation more extensive.

Tooth cysts are almost always benign, and cancerous change within one is rare. The possibility is taken seriously enough that tissue removed during surgery is routinely sent for laboratory examination, which confirms the type of cyst and checks for abnormal cells. Certain types, such as odontogenic keratocysts, are monitored more closely because they erode more bone as they grow and return more often, which is a separate matter from being cancerous. Rapid growth, numbness or an ulcer that does not heal requires prompt further investigation.

Gum cysts do not resolve on a set timeline, as most do not disappear without treatment. The exception is a gingival cyst in a newborn, which usually disappears within a few weeks of birth. In an adult, a cyst in the gum remains until it is removed, after which the swelling typically settles within one to two weeks. The bone underneath takes longer, filling in gradually over three to twelve months, with follow-up X-rays typically used to monitor progress.

An untreated dental cyst continues to enlarge, and the damage builds up slowly rather than suddenly. Bone is typically lost as the cyst expands, which weakens the jaw and, in very large cases, may raise the risk of a fracture. Nearby teeth may loosen, shift, or have their roots worn away. Infection may develop, turning a painless swelling into a painful one. If you have noticed a lump in your jaw or gum, it is advisable to consult a dentist, who can examine it and advise on treatment.

Dental cyst removal is generally not painful during the procedure, as the area is numbed with local anaesthetic, and sedation or general anaesthetic may be considered for larger cysts. Discomfort and swelling are common for the first two to three days afterwards and are usually managed with prescribed pain relief and a cold compress against the cheek. Most people return to normal activity within one to two weeks. Your dentist or oral surgeon will run through the procedure beforehand, so it is advisable to raise any concerns then.

A mouth cyst is only removed through surgery, as it does not resolve with home treatment. Squeezing, piercing or draining one risks pushing infection into the surrounding tissue, and nothing applied to the gum reaches the cyst wall inside, which continues to produce fluid, so the swelling refills even if it bursts. Antibiotics may treat an infection around a cyst without removing the cyst itself. If you have a lump in your mouth, it is advisable to consult a dentist, who can assess the lump and recommend suitable treatment.

A dentist or oral surgeon removes a cyst surgically, usually under local anaesthetic. The gum is lifted, a small opening is made in the overlying bone, and the cyst is lifted out whole, a procedure called enucleation. The bony walls are often scraped afterwards, a step known as curettage, to remove any remaining cells and reduce the chance of regrowth. Larger cysts may be drained first and left open to shrink over several months before final removal. The tooth involved is treated with root canal treatment or extracted during the same operation.

A dental cyst does not normally heal on its own, so signs of healing apply to recovery after its removal. Healing is assessed mainly by swelling and discomfort that reduce steadily over the first week. Bleeding should stop within the first day, and stitches dissolve or are removed after one to two weeks. The cavity in the bone fills with new bone over three to twelve months, monitored on follow-up X-rays. If you have had a cyst removed and develop increasing pain, worsening swelling after day three, fever or discharge, consult your oral surgeon promptly.

The urgency of a dental cyst depends on whether it is causing pain, infection, or difficulty eating and speaking, though any lump in the jaw or gum should be assessed by a dentist rather than monitored at home. A lump cannot be identified as a cyst without an examination and an X-ray. Urgent attention is advisable if the swelling is painful or enlarging quickly, or if there is fever or discharge, as these may indicate infection. Numbness in the lip or chin, a loose tooth or difficulty opening the mouth also requires prompt assessment.

The only way to confirm whether a cyst is cancerous is laboratory examination of the tissue after it has been removed. Before that, an examination and an X-ray indicate how likely a cyst is to be benign: a well-defined round border suggests a benign cyst, while ragged or poorly defined edges require further investigation. Almost all dental cysts are benign, but symptoms that warrant prompt assessment include rapid growth, numbness, bleeding from the lump, or an ulcer that does not heal. If a lump concerns you, it is advisable to consult a dentist.