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Radiographic and Clinical Images:
Demographics: Commonly diagnosed in patients 10-30 years of age. Figures 1 and 2 show radiographic and clinical images of a 7-year old female patient. Slight male predilection than females and a higher prevalence with Caucasians than other ethnicities.1
A benign cyst lined by squamous epithelium, the dentigerous cyst is found where fluid accumulates between the dental follicle and the crown of the unerupted or partially erupted tooth. It may also occur around a supernumerary tooth. One of the most common developmental odontogenic cysts, accounting for approximately 20% of all epithelial-lined cysts of the jaws. The cyst is attached to the CEJ and results from the proliferation of the reduced enamel epithelium after the enamel is formed. This cyst also has a potential origin from past periapical inflammation associated with a nonvital deciduous tooth. In descending order, most commonly associated with mandibular third molars, maxillary third molars, and maxillary canines due to the potential of impaction. The cyst may destroy alveolar bone, resorption of adjacent tooth roots, or displacement of teeth. Although rare, the epithelium has the potential to undergo neoplastic change developing into squamous cell carcinoma or ameloblastoma in the wall of the cyst.2-3
Clinical Notes: Typically asymptomatic, even if quite large (Figure 3). However, large cysts can develop secondary infection with associated pain and edema.4 Lesions are found during radiographic imaging. With this case, the lesion is a well-defined unilocular radiolucent lesion present in the area of tooth #4.
Differential Diagnosis: Radiographically small cysts cannot be distinguished from an enlarged dental follicle. When the follicular space exceeds 5 mm from the crown, it is likely a dentigerous cyst. Odontogenic keratocysts and ameloblastomas may mimic the appearance of follicular cysts. To differentiate between lesions, aspiration may be helpful to differentiate with a potential vascular lesion.3-4
Treatment: Depending on the type of tooth the dentist may allow the tooth to erupt, e.g., canine. The dentist may wish to incise the lesion (cystotomy) and place a drain allowing shrinkage of the lesion by healing, or in the case of a third molar it will require surgical removal with its epithelial lining (enucleation). When removed, the lesion should be submitted for histopathologic evaluation. Large lesions would require adding bone to fill the defect. Postoperative clinical and radiographic observation should continue.1-4
