A cyst formed when the stellate reticulum degenerates:

 # A cyst formed when the stellate reticulum degenerates: 

a. Eruption cyst 

b. Dentigerous cyst 

c. Keratocyst 

d. Radicular cyst 

The correct answer is A. Eruption cyst.

An eruption cyst is a type of dentigerous cyst formed when the stellate reticulum degenerates, leaving a cavity lined by the outer enamel epithelium before or during tooth eruption.

Eruption cyst is defined as an odontogenic cyst with the histologic features of a dentigerous cyst that surrounds a tooth crown that has erupted through bone but not soft tissue and is clinically visible as a soft fluctuant mass on the alveolar ridges.

An eruption cyst or ‘eruption hematoma’ is in fact a dentigerous cyst occurring in the soft tissues (Shear, 1992). Whereas the dentigerous cyst develops around the crown of an unerupted tooth lying in the bone, the eruption cyst occurs when a tooth is impeded in its eruption within the soft tissue overlying the bone.