KQ 20.1 and 20.2. Osteoradionecrosis (ORN) of the jawbone is a rare complication after head and neck radiotherapy (RT). To prevent ORN, the extraction of damaged teeth should be performed before RT, with socket preservation of the teeth extracted in the radiation field. The management of ORN is dependent on the stage and condition of the patient. It includes medication, mouthwash, hyperbaric oxygen therapy (HBO), and curettage of sequestrum. Fibular free-flap reconstruction is the flap of choice for the reconstruction of the maxilla and mandible in stage III patients. Dental implant-supported prostheses should be considered for restoring mastication and swallowing function. KQ 20.3. Osteoradionecrosis (ORN) is a challenging radiation-induced complication. Conservative management, including hyperbaric oxygen therapy (HBOT), is indicated in the early stage, which implies that lesions of short length are confined to the alveolar bone or exposed alveolar bone without pathological fracture. The preventive role of HBOT is not well established. Early recognition of ORN and multidisciplinary treatment approaches, including HBOT, are pivotal for improving treatment outcomes.