An unerupted tooth is a tooth that has failed to emerge normally into the oral cavity and remains trapped inside the jawbone. The condition is surprisingly common, especially in dogs — approximately 5–7% of dogs are affected, and the proportion is even higher in brachycephalic (short-nosed) breeds. A dentigerous cyst can develop around an unerupted tooth — a fluid-filled structure that grows slowly and destroys the jawbone. Without dental X-rays, the condition goes undetected until significant damage has already occurred. At our clinic, we perform dental radiography and surgical extraction of unerupted teeth.
What Is a Dentigerous Cyst?
During normal tooth development, the enamel membrane (the reduced enamel epithelium) surrounding the tooth crown breaks down as the tooth erupts. When a tooth fails to erupt, this epithelial layer remains intact and fluid accumulates, forming a cyst. The cyst grows slowly but inevitably: the fluid creates pressure that activates the jawbone's resorption cells (osteoclasts). Studies show that 29–50% of unerupted teeth develop a dentigerous cyst.
Symptoms — Often Asymptomatic
A dentigerous cyst is often completely asymptomatic in the early stages — this makes it particularly insidious. The most common finding is a "missing tooth" on oral examination: a tooth that should be present is not visible. Other signs may include jaw swelling, displacement or tilting of adjacent teeth, and in advanced cases a fistula (draining tract). In the worst case, the cyst weakens the jawbone so much that a pathological fracture occurs — the jaw breaks under normal load.
At-Risk Breeds
Brachycephalic (short-nosed) breeds are at greatest risk because their shortened jaw does not provide enough space for all teeth. Boxers, English Bulldogs, French Bulldogs, Boston Terriers, Pugs, and Shih Tzus are particularly overrepresented. Small breeds such as Maltese, Yorkshire Terriers, Chihuahuas, Miniature Poodles, and Dachshunds are also at risk. In cats, unerupted teeth and dentigerous cysts are rare but possible — the same principles apply.
Diagnosis — Dental X-Rays Are Essential
An unerupted tooth and dentigerous cyst cannot be detected with the naked eye — the only way is dental X-rays. On the radiograph, a well-defined, round or oval radiolucent area (a fluid-filled cavity) appears around the crown of the unerupted tooth. The X-ray also reveals the extent of bone loss and the effect on adjacent teeth. This is why we recommend full-mouth radiographs with every dental procedure — studies show that dental X-rays change the treatment plan in 28–50% of patients by revealing hidden problems.
Treatment — Surgical Extraction
Treatment involves surgical extraction of the unerupted tooth and thorough curettage of the cyst cavity to remove all epithelial cells. The procedure involves raising a mucoperiosteal flap, opening a window in the bone, removing the tooth and the entire cyst wall, and closing the wound. The bone cavity fills with new bone within 2–6 months. Left untreated, the cyst continues to grow, destroys bone, and can lead to pathological fracture — a cyst never resolves on its own. At Eläinklinikka Saari, we perform surgical extractions of unerupted teeth and cyst surgery is part of our dental services — book an appointment for a dental examination and we will assess the situation.
Prognosis
The prognosis for an early-detected and completely removed dentigerous cyst is excellent. The risk of recurrence is low when the cyst wall has been entirely removed. The prognosis is worse if the cyst has grown large, extensive bone has been destroyed, or the jaw has already fractured. This is why early diagnosis is crucial — dental X-rays are the best way to find unerupted teeth before a cyst has time to form.