The most common cause of chronic swelling of the jaws is a cyst.
A cyst is defined as a pathological cavity filled with fluid and lined by epithelium. This epithelium can originate either from the tooth-forming organ (odontogenic) or from other sources such as areas of
Aims for undergraduates and postgraduates 153 Learning outcomes 153 Classification of cysts of the jaws 153 Epithelial cysts 153 Nonepithelial cysts 161
inclusion of epithelium when the embryonic processes of the face fuse (nonodontogenic). Odontogenic cysts account for the large majority (90%) of jaw cysts.