Introduction: Osteoradionecrosis (ORN) of the jaws is a late, severe and difficult to manage side effect in patients who underwent radiotherapy (RT) in the head and neck region. Treatment remains controversial, especially in refractory cases that do not respond to multiple attempts with different therapies, due to their complex pathophysiology. It is based on conservative non-surgical approaches, even in large resections using free flaps. The present study aims to present and describe a clinical case of refractory ORN treated through microsurgical reconstruction and adjuvant therapies. Case Report: A 51-year-old female patient with oncological background of oral squamous cell carcinoma (OSCC) of the floor of the mouth, previously treated with marginal mandibulectomy, and who subsequently relapsed. In a second surgical time, left hemimandibulectomy was performed, followed by microsurgical reconstruction with the fibular osteomusculocutaneous free flap, besides, dental implants were placed in the perioperative time. Radiotherapy was performed using a 3D conformal technique technique with a total dose of 66 Gy and after six months the patient developed infection in the treated region and it was observed partial exposure of the fibular flap and intra and extraoral purulent drainage, and after imaging analysis the diagnosis of ORN was established. Some non-surgical therapeutic attempts were performed without clinical response and a new surgical approach was performed based on sequestrectomy, the removal of the titanium plaque and dental implants with a second microsurgical reconstruction with forearm fasciocutaneous free flap to cover the soft tissue defect was done. Conclusion: The pathophysiology of ORN remains controversial and the predictive factors for its appearance, development, and progression are still unclear. Marginal mandibulectomy could be associated with a rapid onset of ORN in patients submitted to adjuvant RT and it could be considered as a potential predictive factor. Combined therapies are reliable alternatives for local control in refractory cases and in advanced stages, and surgical removal with microsurgical reconstruction procedures are still a feasible alternative that has shown satisfactory clinical results.

Introduction: Osteoradionecrosis (ORN) of the jaws is a late, severe and difficult to manage side effect in patients who underwent radiotherapy (RT) in the head and neck region. Treatment remains controversial, especially in refractory cases that do not respond to multiple attempts with different therapies, due to their complex pathophysiology. It is based on conservative non-surgical approaches, even in large resections using free flaps. The present study aims to present and describe a clinical case of refractory ORN treated through microsurgical reconstruction and adjuvant therapies. Case Report: A 51-year-old female patient with oncological background of oral squamous cell carcinoma (OSCC) of the floor of the mouth, previously treated with marginal mandibulectomy, and who subsequently relapsed. In a second surgical time, left hemimandibulectomy was performed, followed by microsurgical reconstruction with the fibular osteomusculocutaneous free flap, besides, dental implants were placed in the perioperative time. Radiotherapy was performed using a 3D conformal technique technique with a total dose of 66 Gy and after six months the patient developed infection in the treated region and it was observed partial exposure of the fibular flap and intra and extraoral purulent drainage, and after imaging analysis the diagnosis of ORN was established. Some non-surgical therapeutic attempts were performed without clinical response and a new surgical approach was performed based on sequestrectomy, the removal of the titanium plaque and dental implants with a second microsurgical reconstruction with forearm fasciocutaneous free flap to cover the soft tissue defect was done. Conclusion: The pathophysiology of ORN remains controversial and the predictive factors for its appearance, development, and progression are still unclear. Marginal mandibulectomy could be associated with a rapid onset of ORN in patients submitted to adjuvant RT and it could be considered as a potential predictive factor. Combined therapies are reliable alternatives for local control in refractory cases and in advanced stages, and surgical removal with microsurgical reconstruction procedures are still a feasible alternative that has shown satisfactory clinical results.