What best defines a residual cyst?

A residual cyst is appropriately defined as a cystic lesion that remains following the extraction of a tooth, particularly when a cyst was present but not completely removed during the extraction process. This can occur if the cystic tissue is left in place inadvertently or if there is an incomplete treatment of the cyst before the extraction.

It is characterized by its location in the alveolar bone where a tooth has been previously removed, making it a direct result of the previous pathology related to that tooth. This distinction is crucial for dental professionals, as identifying a residual cyst correctly can lead to appropriate management and treatment, often requiring surgical intervention to remove the remaining cystic tissue.

The other definitions don't accurately encompass what a residual cyst is. For instance, a new growth from a previously removed cyst pertains to a different clinical scenario where a cyst might recur or develop anew after treatment, while a type of keratocystic odontogenic tumor refers specifically to a particular form of cystic lesion with unique histological features. A misinterpreted benign cyst suggests a diagnostic error rather than a specific definition of a residual cyst.