- Dental cyst
Name = Dental cyst
Caption = CT scan through head showing a right dental cyst
DiseasesDB = 31994
ICD10 = ICD10|K|09|0|k|00
eMedicineSubj = ent
eMedicineTopic = 681
Dental cysts (also termed Periapical cyst, Radicular cyst, Odontogenic cysts) are cystic lesions arising from teeth. They are also known as odontogenic cysts. Dental cysts are in fact the commonest of all odontogenic cysts.
Dental cysts are usually caused due to root infection involving the tooth closely related to the maxillary sinus antrum. The resulting pulpal necrosis causes release of toxins at the apex of the tooth leading to periapical inflammation. This inflammation stimulates the Malassez epithelial rests, which are found in the periodontal ligament, resulting in the formation of a periapical granuloma that may be infected or sterile. The epithelium undergoes necrosis and the granuloma becomes a cyst. These lesions can grow into large lesions because they apply pressure over the bone causing erosion. The toxins released by the granulation tissue is one of the common causes of bone erosion.
These cysts are not true neoplasms.
Expansion of the cyst causes erosion of the floor of the maxillary sinus. As soon as it enters the maxillary antrum the expansion starts to occur a little faster because there is space available for expansion. Tapping the affected teeth will cause shooting pain. This is virtually diagnostic of pulpal infection.
Radiographically it is virtually impossible to differentiate granuloma from a cyst. If the lesion is large it is more likely to be a cyst. Radiographically both granuloma and cyst appear radiolucent, associated with the apex of non vital tooth.
If the cyst is small endodontic therapy may help. Larger cysts will have to be surgically removed.
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