Prevention of osteoradionecrosis of the jaws by low-intensity ultrasound in the dog model

The Progress in Reconstruction of Mandibular Defect Caused by Osteoradionecrosis

Osteoradionecrosis (ORN) is described as a disease with exposed, nonviable bone that fails to heal spontaneously or by means of conservative treatment after radiotherapy in at least 3 months. Though traditional theories in the early stage including hypoxic-hypocellular-hypovascular and fibro-atrophic in addition to new findings such as ferroptosis were put forward to explain the mechanisms of the osteoradionecrosis, the etiology of ORN is still unclear. With the high rate of occurrence in the head and neck area, especially in the mandible, this disease can disrupt the shape and function of the irradiated area, leading to a clinical presentation ranging from stable small areas of asymptomatic exposed bone to severe progressive necrosis. In severe cases, patients may experience pain, xerostomia, dysphagia, facial fistulas, and even a jaw defect. Consequently, sequence therapy and sometimes extensive surgery and reconstructions are needed to manage these sequelae. Treatment options may include pain medication, antibiotics, the removal of sequesters, hyperbaric oxygen therapy, segmental resection of the mandible, and free flap reconstruction. Microanastomosed free-flaps are considered to be promising choice for ORN reconstruction in recent researches, and new methods including three-dimensional (3-D) printing, pentoxifylline, and amifostine are used nowadays in trying increase the success rates and improve quality of the reconstruction. This review summarizes the main research progress in osteoradionecrosis and reconstruction treatment of osteoradionecrosis with mandibular defect.

The Potential Therapeutic Role of Mesenchymal Stem Cells-Derived Exosomes in Osteoradionecrosis

As one of the most serious complications of radiotherapy, osteoradionecrosis (ORN) seriously affects the quality of life of patients and even leads to death. Vascular injury and immune disorders are the main causes of bone lesions. The traditional conservative treatment of ORN has a low cure rate and high recurrent. Exosomes are a type of extracellular bilayer lipid vesicles secreted by almost all cell types. It contains cytokines, proteins, mRNA, miRNA, and other bioactive cargos, which contribute to several distinct processes. The favorable biological functions of mesenchymal stem cells-derived exosomes (MSC exosomes) include angiogenesis, immunomodulation, bone regeneration, and ferroptosis regulation. Exploring the characteristic of ORN and MSC exosomes can promote bone regeneration therapies. In this review, we summarized the current knowledge of ORN and MSC exosomes and highlighted the potential application of MSC exosomes in ORN treatment.

Overview and Emerging Trends in the Treatment of Osteoradionecrosis

OPINION STATEMENT

Osteoradionecrosis (ORN) of the mandible is a rare but devastating complication which occurs following radiation therapy for head and neck malignancies. Left untreated, ORN often results in pathologic fracture of the mandible leading to pain, trismus, difficulty eating, and overall poor quality of life. Historically, early intervention relied on hyperbaric oxygen and local debridement. Patients whose disease progressed despite therapy required segmental resection of the mandible with osseous free flap reconstruction, a highly invasive operation. Patients that presented with a moderate disease without pathologic fracture were often doomed to fail non-operative management, ultimately leading to disease progression and fracture. The traditional dichotomous treatment paradigm left a void of options for patients with moderate disease. The ideal intervention for this category of patients would provide renewed vascularity to the diseased tissue bed allowing for the osteogenesis and reestablishment of strong, load-bearing bone. The innovative technique termed the vascularized fascia lata "rescue flap" has proven to be an effective treatment for moderate ORN and will likely transform dated treatment algorithms.

Osteoradionecrosis of the Midface and Mandible: Pathogenesis and Management

Radiation therapy is an important and commonly used treatment modality for head and neck cancers. Osteoradionecrosis (ORN) is a potential debilitating complication of treatment, which most commonly affects the mandible. Management strategies are tailored to the severity of disease. Medical management including oral rinses, irrigations, antibiotics, and pharmacological treatments is viable for mild-to-moderate ORN. More severe disease is best addressed with a combination of medical management and surgical intervention aimed at aggressively removing devitalized tissue until bleeding bone is encountered and reconstructing the soft tissue and bone defect. Reconstruction with either regional vascularized flaps or vascularized osteocutaneous free flaps in case of larger full-thickness bone defects (greater than 6 cm) or anterior mandible (medial to mental foramen) is most appropriate. Maxillary ORN complications can present with a wide range of functional problems and facial disfigurement. Life-threatening and time-sensitive problems should be treated first, such as skull base bone coverage or correction of severe ectropion, to avoid blindness from exposure keratopathy. Then, less time-sensitive issues can be addressed next, such as nasal obstruction, velopharyngeal insufficiency, and chronic tearing. It may require a combination of specialists from different disciplines to address various issues that can arise from maxillary ORN.

Chinese expert group consensus on diagnosis and clinical management of osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible (MORN) is one of the most devastating complications caused by radiation therapy in the head and neck region. It is characterized by infection and chronic necrosis of the mandible as the main manifestation. Clinically, MORN-related symptoms include swelling, pain, dysphagia, trismus, masticatory or speech disorders, refractory orocutaneous fistula, bone exposure, and even pathological fracture. MORN has become a challenging clinical problem for oral and maxillofacial surgeons to deal with, but thus far, this problem has not been solved due to the lack of widely accepted treatment algorithms or guidelines. Because of the nonexistence of standardized treatment criteria, most clinical treatment against MORN nowadays is largely based on controversial empirical understandings, while recommendations on post-therapeutic evaluations are scarce. Therefore, to further unify and standardize the diagnosis and treatment of MORN, to decrease the huge waste of medical resources, and ultimately, to improve the wellbeing of the patients, the Chinese Society of Oral and Maxillofacial Surgery (CSOMS) convened an expert panel specialized in MORN from 16 domestic medical colleges and affiliated hospitals to discuss the spectrum of diagnosis and and formulate treatment. In addition, consensus recommendations were also revised with a comprehensive literature review of the previous treatment experiences and research pearls. This 'expert consensus statement on diagnosis and clinical management of MORN' is for clinical reference.