Periapical Cyst Overview

Study Notes

Development of Periapical Cysts

Initially, periapical cysts swell to a round hard protrusion, but later the body resorbs some of the cyst wall, leaving a softer accumulation of fluid underneath the mucous membrane.
Secondary symptoms of periapical cysts include inflammation and infection of the pulp, causing dental caries and necrosis of the pulp.

Characteristics of Periapical Cysts

Larger cysts may cause bone expansion or displace roots.
Discoloration of the affected tooth may occur.
Patients may present negative results to electric and ice tests of the affected tooth, but will be sensitive to percussion.
Surrounding gingival tissue may experience lymphadenopathy.
The alveolar plate may exhibit crepitus when palpated.

Complications of Periapical Cysts

Expansion of the cyst causes erosion of the floor of the maxillary sinus.
As the cyst enters the maxillary antrum, the expansion rate increases due to available space for expansion.
Performing a percussion test by tapping the affected teeth will cause shooting pain, which is often clinically diagnostic of pulpal infection.

Causes of Periapical Cysts

Periapical cysts are usually caused by root infection involving tooth decay.
Untreated dental caries allow bacteria to reach the level of the pulp, causing infection.
The bacteria gain access to the periapical region of the tooth through deeper infection of the pulp, traveling through the roots.
The resulting pulpal necrosis causes proliferation of epithelial rests of Malassez, which release toxins at the apex of the tooth.

Stages of Periapical Cyst Development

Initial stage: Epithelial cells from the rests of Malassez at the apex of the roots of a non-vital tooth become stimulated due to the body's inflammatory response to bacterial endotoxins infecting the pulp or as a direct response to necrotic pulp tissue.
The cyst develops due to an inflammatory stimulus in 3 stages.

General Information

Periapical cysts are commonly known as dental cysts and are the most common odontogenic cyst.
They may develop rapidly from a periapical granuloma as a consequence of untreated chronic periapical periodontitis.
Periapical cysts are usually located in the maxillary anterior region and are caused by pulpal necrosis secondary to dental caries or trauma.
The cyst's lining is derived from the epithelial cell rests of Malassez, which proliferate to form the cyst.

Description

Learn about the periapical cyst, also known as a radicular cyst or inflammatory cyst, which is the most common odontogenic cyst in dentistry. Understand its development from a periapical granuloma due to untreated chronic periapical periodontitis and its characteristics.