Cysts Flashcards
Define a cyst (4)
- A pathologic cavity filled with fluid
- Lined by epithelium
- Surrounded by a connective tissue wall
- Fluid is secreted by cells lining the cavity
Define a cystlike lesion
A pathologic cavity filled with fluid but lacking an epithelium
3 classes of cysts
- Odontogenic cysts
- Nonodontogenic cysts (developmental cysts)
- Cystlike lesions
2 classes of odontogenic cysts
- Inflammatory cysts
- Developmental cysts
Describe the mechanism of cyst enlargement
4 clinical symptoms of cysts
- Swelling
- Lack of pain
- Frequent association with teeth
- Sometimes cyst becomes infected –> painful
Where are cysts located (5)
- Within bone
- Any location in the maxilla or mandible
- Odontogenic cysts most often in tooth-bearing region
- In mandibule –> above mandibular canal
- In maxilla –> may grow into the maxillary sinus
Describe the periphery and shape of cysts (3)
- Well-defined periphery with a thin, radiopaque line
- Sometimes, secondary infection can change this aspect into more sclerotic (thicker) boundary)
- Usually round or oval shape
Describe the internal structure of cysts (3)
- Radiolucent
- Long-standing cysts have calcifications
- Some cysts have septa which produce multiple loculations
5 effects of cysts on surrounding structures
- Tooth displacement
- Tooth resorption
- Bone expansion
- Displacement of the mandibular canal
- Cyst may invaginate into the maxillary sinus
Define a radicular cyst
A cyst that most likely results when rests of epithelial cells in the periodontal ligament are stimulated to proliferate and undergo cystic degeneration by inflammatory products from a nonvital tooth
2 types of inflammatory cysts
- Radicular cysts
- Residual cysts
5 clinical features of radicular cysts
- Most frequent cysts of the jaws
- Arise from nonvital teeth
- Asymptomatic unless secondary infection occurs
- Swelling (large cysts)
- Incidence of radicular cysts is greater between 30 - 60 years
4 radiographic features of radicular cysts
- Located at the apex of a nonvital tooth
- Well-defined cortical border
- Round shape
- Radiolucent
4 effects of radicular cysts on surrounding structures
- Displacement and root resorption of the adjacent teeth
- Cortical expansion
- Invagination into the maxillary sinus
- Displacement of the mandibular canal
4 differential diagnoses of radicular cyst
- Apical granuloma
- Early stage of periapical cemental dysplasia
- Central giant cell granuloma
- Malignant tumor (metastasis)
How to differentiate a radicular cyst from an apical granuloma
- A small radicular cyst may be impossible to differentiate from an apical granuloma
- Well-defined cortical border, size greater than 1 cm are more characteristic of a cyst
How to differentiate early stage of periapical cemental dysplasia from radicular cysts
- Around vital teeth
- Anterior teeth of the mandible
- Black women more prevalent
Define lateral radicular cyst
A radicular cyst originating from an accessory root canal (existence of a lateral root canal)
Differential diagnosis for lateral radicular cyst
Lateral periodontal cyst
Define residual cyst
A cyst that remains after incomplete removal of the original cyst. A radicular cyst or granuloma left after extraction of a tooth.
4 clniical features of residual cysts
- Asymptomatic
- Often discovered on radiographic examination of edentulous area
- Bone expansion
- Pain in the case of secondary infection
6 radiographic features of residual cysts
- Oval or circular shape
- Well-defined border
- Cortical or sclerotic border (if it become secondarily infected)
- Radiolucent
- Cortical expansion
- Tooth displacement or resorption
2 differential diagnoses for residual cysts
- Other solitary cysts (odontogenic keratocyst; slight cortical expansion)
- Stafne bone defect (below the mandibular canal)