Abstract: Osteoradionecrosis of the jaws (ORNJ) is one of the most serious and important complications of radiotherapy for head and neck cancer, which often leads to severe pain, pathological fracture, sequestration of devitalized bone, and orocutaneous fistulas, and seriously reduces the patients’ survival quality and is even life-threatening. Although many theories of how it occurs have been formulated, the exact etiology and pathogenesis of ORNJ is not certain. The purpose of this article is to review and summarize the progress of studies on etiology and pathogenesis of ORNJ.

Key words: Osteoradionecrosis, Jaws, Etiology, Pathogenesis