Odontogenic keratocyst is a locally aggressive developmental cyst that may appear in the mandibular third molar or canine region. It varies in size and as it widens it may interfere with the surrounding structures as teeth by compressing on their nerves and blood supply. Treatment is usually accomplished by enucleation, curettage and then bone grafting of the cystic space. Any non-vital tooth nearthe cyst space region may extrude toxic substances from the dead pulp space. The interaction between the extruding irritants from the root canal space and the host defense results in activation of numerous. inflammatory reactions which will not allow healing to the periapical region. Instrumenting and irrigating the root canal will remove all harmful microorganisms and leave a clean disinfected space. Obturating of the pulp space ensures blocking the space with inert or bioactive material that will enhance bone healing.
