RADICULAR CYST An odontogenic cyst derived from Cell Rests of Malassez that proliferate in response to inflammation. Also known as : Apical Periodontal Cyst Periapical Cyst Root End Cyst
TYPES OF RADICULAR CYST 1. Apical 70% 2. Lateral 20% 3. Residual Most common location: Maxillary anterior region Maxillary posterior region Mandibular posterior region Mandibular anterior region
EPIDEMIOLOGY Common – C onstitutes approx one half to three fourth of all cysts in the jaws Relative frequency: 60-70% Frequent in ages between 20-60 years (rarely in <10years age) (Peaks in third through sixth decades) Maxilla is 3 times more affected than mandible M/F ratio: 3:2
CLINICAL FEATURES Usually asymptomatic Slowly progressive If infection enters, the swelling becomes painful & rapidly expands (partly due to inflammatory edema) Initially swelling is round & hard. Later, part of wall is resorbed leaving a soft fluctuant swelling, bluish in color, beneath the mucous membrane.
When bone has been reduced to egg shell thickness , a crackling sensation may be felt on pressure.
PATHOGENESIS CARIES , TRAUMA, PERIODONTAL DISEASE, PULPAL NECROSIS ( Death of Dental Pulp ) Necrotic Debris is Inflammatory Stimulus PERIAPICAL INFLAMMATION PERIAPICAL GRANULOMA Composed of granulation tissue, scar & inflammatory cells PROVIDE RICH VASCULAR AREA TO RESTS OF MALASSEZ RESTS OF MALASSEZ PROLIFERATE
FORM LARGE MASS OF CELLS INNER CELLS OF MASS DEPRIVED OF NOURISHMENT UNDERGO LIQUEFACTION NECROSIS FORMATION OF A CAVITY IN THE CENTRE OF GRANULOMA RADICULAR CYST / PERIAPICAL CYST Cyst wall separates from bone due to pulpal irritation
DIAGNOSIS Diagnosis is done by the combination of : Radiographic appearances . A non vital tooth . Appropriate histopathological appearances. By definition, a non vital tooth is necessary for the diagnosis of a periapical cyst.
Clinical Findings Signs And Symptoms: Small radicular cysts do not usually become acutely infected, are frequently asymptomatic, and can be identified on routine dental x-rays. Larger cysts may produce expansion of the bone, displacement of tooth roots, and crepitus on palpating the expanded alveolar plate. The discoloration of non vital teeth along with a negative response of the affected tooth to electric pulp testing or ice are the presenting signs. In addition, infected radicular cysts are painful, the involved tooth is sensitive to percussion, and there may be swelling of the overlying soft tissues and lymphadenopathy.
RADIOGRAPHIC FEATURES Identical to periapical granuloma. Since the lesion is a chronic progressive one developing in a pre-existing granuloma • cyst may be of greater size than granuloma • due to longer duration Occasionally, exhibits thin, radiopaque line around the periphery of radiolucent area. Radiolucency associated is generally round to ovoid. Indicates reaction of bone to slowly expanding mass.
Majority cysts <1.5 cm in diameter. Long standing cysts: May cause resorption of offending tooth and occasionally of adjacent teeth. Periapical cyst is well circumscribed. Distinct line of cortication seperating it from the surrounding teeth. May be associated with the resorption of apices of teeth, displacement of teeth or both.
TREATMENT Root canal filling ( removal of necrotic pulp; the inflammatory stimuli ). Extraction of the involved non-vital tooth & curettage of apical zone. Root canal filling in association with apicoectomy (direct curettage of the lesion ). Surgery ( apicoectomy and curretage ) is performed for lesions that are persistent, indicating the presence of a cyst or inadequate root canal treatment.
If the cyst is incompletely removed residual cyst. Continued growth of the cyst can cause significant bone resorption along with weakening of the maxilla and mandible. Enucleation Marsupialization