Cysts are round cavities made up of two membranes; outer or connective membrane and inner or epithelial membrane. The content that fills its interior can be watery, colloid-like or semi liquid. According to the second division of The World Health Organisation from 1992, cysts of the jaw are classified as either developmental cysts or inflammatory cysts. Developmental cysts are classified as odontogenic, i.e. those which develop from odontogenic epithel in some stage of tooth development, and non-odontogenic, those whose growth is not directly related to the tooth. Inflammatory cysts are of the inflammatory ethiology, meaning that they are the result of an inflammation of the root canal or periodontal space. According to dr. Ivo Miše, cysts are categorized as bone cysts or soft-tissue cysts, considering that the localisation of the cysts is important for defining a corrective treatment. Cystic changes are most commonly manifested by round or oval enlightenment of clearly defined edges, but sometimes it is necessary to differentially diagnose other pathological entities that give a similar image, but different etiology and behaviour. It is often difficult to obtain a proper diagnosis based on a clinical picture and an X-ray finding, so it is necessary to employ other diagnostic methods such as cystic content puncture, CT, CBCT, MR, and other. Diagnostic methods make it easier for the clinician to set up a diagnosis and a provide a clearer way to an adequate choice of treatment.