A dentigerous cyst, also known as follicular cyst is a type of odontogenic cyst. This cyst develops from the accumulation of fluid between the reduced enamel epithelium and the crown of an unerupted tooth. It attaches to the tooth neck at the cemetoenamel junction. This is the second most frequently found type of odontogenic cyst.
Dentigerous Cyst Causes
Some experts suggest that these cysts might be caused due to Periapical inflammation of non-vital deciduous teeth present near the follicles of unerupted permanent successors. The inflammation takes place when the fluid accumulates inside the developmental sac, or follicle around an unerupted tooth. The fluid accumulates once the enamel has finished forming. This results in the cyst getting attached to the tooth at a point where the enamel meets the root.
Dentigerous Cyst Symptoms
The symptoms of dentigerous cysts are:
- They are painless.
- Large cysts may lead to displacement of teeth.
- Disruption of the jaw, or a fracture in extreme cases.
- An infected cyst may get transformed into an ameloblastoma that invades the surrounding tissues.
- Dentigerous cysts may also lead to recurrent head and neck infection.
Dentigerous Cyst Diagnosis
Dentigerous Cysts can be diagnosed through CT and MRI scans. They help in distinguishing this cyst from other cystic lesions that occurs in the oral cavity.
A dentigerous cyst usually occurs when the distance between the crown and dental sac is more than 2.5 to 3.0 mm.
Following are the diagnostic methods used to detect this cyst.
In this test, the cyst cavity is shown to be filled with water density fluid. Lesions in maxillary region might project into the nasal cavity or paranasal sinuses.
Following are observed in radiography.
- Dentigerous cysts are unilocular well defined pericoronal radiolucencies crowded around an unerupted tooth.
- The cysts show a thin sclerotic margin along with enlargement of the cortex lying above without cortex breach.
- Erosion or resorption of adjacent teeth may also be observed at times.
This imagery test shows the following:
- T1 image: low signal, similar to water
- T2 image: high signal, similar to water
- T1 C+: a thin peripheral rim of enhancement is observed
Histological test shows the following:
- The cyst is lined by non-keratinized stratified squamous epithelium.
- Often the dentigerous cyst might give rise to a more fatal mucoepidermoid carcinoma.
- Dentigerous cysts are known to expand rapidly which can cause pathological fractures of jaw bones.
Differential diagnosis may be required for further differentiation of this cyst with other lytic lesions of the jaw.
- Aneurysmal bone cyst
- Fibrous dysplasia
- Periapical cyst
- Stafne cyst
- Aneurysmal bone cyst
- Odontogenic keratocyst
Dentigerous Cyst Treatment
Surgery is required if the cyst is too large or might affect several teeth or tooth buds at a go. Thus, the cyst along with the affected tooth is removed. Marsupialization is usually done before surgery in cases of large cysts. Recurrence of cyst is very rare after removal.
Dentigerous Cyst Complications
Few complications might occur with these cysts.
- Risks of large jaw fracture.
- Dentigerous cysts might give rise to mural ameloblastoma
- Risks of development of squamous cell carcinoma in the context of chronic infection.