The Radicular cyst is usually an inflammation of dental pulp. These cysts may also be found on the lateral aspects of the roots. It develops from a slow growing fluid filled epithelial sac located at the apex of the tooth. They originate from pupal necrosis of a non-vital tooth. These epithelial sacs develop from left over tissues after tooth development. It is the most common odontogenic cyst. Radicular cysts are generally sterile unless they are infected secondarily.
Radicular Cysts consists of four components.
- The cystic lumen
- The epithelial cyst wall
- The connective tissue mass
- A subepithelial region that contains chronic inflammatory infiltration.
Radicular Cyst Stages
Radicular Cyst develops through three stages.
- Phase 1- Initiation
- Phase 2- Cyst formation
- Phase 3- Cysts Growth (enlargement)
Radicular Cyst Causes
These cysts are caused due to infection at the root of a tooth by carious decay. This results in pupal necrosis, a process which injects toxins at the apex of the tooth. This leads to Periapical inflammation.
How does a radicular cyst develop?
The Periapical inflammation results in formation of scar tissues which are called Periapical granuloma. Further damage stimulates the ‘malassez epithelial rests’ which are often found on periodontal ligament which ultimately leads to the development of a cyst. These lesions might grow into large lesions and exert pressure over the bone that leads to resorption.
Radicular Cyst Types
Radicular Cyst can be classified into three types:
Lateral Radicular Cyst
These are the Radicular cysts which develop at the opening of lateral accessory root canals of infectd tooth.
These cysts develop at the root apex.
These are the cysts which continue to exist even after an infected tooth has been removed.
Radicular Cyst Symptoms
The symptoms of Radicular cyst development are as follows:
- Sclerotic border
- Teeth non-vital
- May develop in other harmless lesions
- Periapical lucency
- Slow enlargement.
- Painless swelling.
Radicular Cyst Diagnosis
Radicular Cysts are accidentally discovered while conducting radiography. They can also be diagnosed through histologic method.
Following signs are noticed when radiography is done.
- Involvement of the root of maxillary incisors and mandicular molars.
- No destruction or displacement of teeth.
- Images show a round or flask shaped radiolucency along with prominent radiopaque margin.
- Image details also show fragments of glistening or granular soft tissue.
The radicular histology reveals the following:
- The remains of lamellar bone inside the cavity of the cyst.
- The epithelial wall shows a multiple layered squamous epithelium.
- Presence of multinuclear giant cells which indicates presence of possible foreign body reaction and osteoclastic cavity.
- Adjacent plasma cells produce antibodies IgG and IgA and also some amounts of IgM and IgE. This is an indication of immune activity.
- Presence of cholesterol crystals inside the lumen of radicular cyst.
Sometimes it gets difficult to distinguish a dentigerous cyst and a radicular cyst. In those cases, differential diagnosis needs to be done by the pathologist.
Differential diagnosis should be done for the following:
- Periapical Scar
- Periapical Granuloma
- Aneurysmal Bone Cyst
- Traumatic Bone Cyst
- Mandibular Infected Buccal Cyst
- Globulomaxillary Cyst
- Mandibular Infected Buccal Cyst
- Periapical Cemental Dysplasia
- Periapical Cemento-osseous dysplasia
Radicular cyst can be treated with the help of following methods.
The affected tooth is either preserved by root canal treatment or is removed. In this method, a mucoperiosteal flap lying over the cyst is raised and a window is opened in the bone which gives sufficient access. The cyst is then separated from the bony wall. The edges off the cavity are smoothened and the cavity is washed to clean the debris. After the bleeding is controlled, the flap is replaced back and stitched.
In this method, peripheral lesions along with the radicular cysts are removed once the causative agents are eliminated. Most of the radicular cysts undergo resolutions after root canal treatment and do not require surgery.
This method is aimed at producing self cleansing cavity which becomes the ground for oral tissues. Here the cyst is cut open for enucleation but the epithelial lining is stitched on to the mucous membrane at margins of opening. The cavity is plugged with ribbon gauze in the beginning. Once the margins get healed, the cavity closes when the surrounding tissues start growing back along with new bones. This method is undertaken only when there is a large cyst which will require decompression, and where the jaw has chances of getting fractured.
Radicular Cyst Complications
Complications might occur after the removal of radicular cysts.
- Fractured jaw
- Surrounding structures such as nerves, cheeks, blood vessels, teeth and roots of tooth might get damaged with serious consequences.
- Infection in the wound.
- Fatal cysts might not be removed properly with added tissue.
- Remains of cyst left behind can lead to recurrence of cyst formation.
Radicular Cyst Prognosis
The prognosis of this condition depends on the extent of bone damage and the possibilities of proper access to the affected region without further complications.