Risk factors of medication-related osteonecrosis of the jaw: A clinical investigation

Medication-related osteonecrosis of the jaw (MRONJ) is an intractable condition caused by drugs such as bisphosphonates and denosumab. This study investigated the changes in the incidence of MRONJ in the previous 10 years and examined the poor prognostic factors during surgery in at-risk patients. We compared 57 and 64 patients diagnosed with MRONJ at our hospital between January 2012 and December 2016 and January 2017 and December 2021, respectively. The disease stage and triggers at the time of initial diagnosis in eligible patients were investigated. Additionally, the adverse prognostic factors were examined in 166 patients at risk of MRONJ who underwent tooth extraction at our department during these 10 years. The results indicated that there was no change in the proportion of patients with osteoporosis and malignancy among those with MRONJ. The number of cases after tooth extraction decreased, and those after dental infections increased on comparing the recent 5 years and the preceding 5 years. The number of MRONJ patients receiving denosumab also increased. Denosumab was a significant post-extraction prognostic factor for delayed healing in the 166 patients at risk of MRONJ. The findings suggest that patients receiving denosumab should be closely monitored when undergoing surgery to prevent MRONJ.

Clinical Diagnostic Imaging Study of Osteoradionecrosis of the Jaw: A Retrospective Study

Radiation therapy (RT) plays a significant role in the management of head and neck malignancies. This study aimed to review the clinical symptoms and various imaging findings of osteoradionecrosis (ORN) and provide a clinical perspective on the development of ORN. The retrospective cohort was composed of 57 sites in 54 patients who had a history of RT and suspected ORN and 48 sites in 45 patients who were confirmed to have ORN. Image analyses included computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET)/CT, bone scintigraphy, and single-photon emission CT (SPECT). The irradiated tissue was damaged by RT, and the extent of damage was correlated with clinical symptoms. The bone marrow showed sclerotic changes and the devitalized bone showed bone resorption after invasive stimulation. Chronic trismus and pathological fracture are considered severe conditions, typically occurring in the last stage of ORN. Furthermore, neurological symptoms were an important sign of tumor recurrence, since diagnostic imaging was difficult. The possible treatment options vary depending on the stage of ORN. We speculate that bone sclerosis reactions and bone resorption are sequential reactions that seem to be protective measures of the bone to radiation injury.

An unusually large osteochondroma of the mandibular angle: a case report

BACKGROUND

Osteochondroma is a benign bone tumor that can occur in both the mesenchymal and craniofacial bones. However, craniofacial osteochondromas are extremely rare, because the mandible develops by intramembranous ossification rather than by endochondral ossification.

CASE PRESENTATION

The most common site of craniofacial osteochondroma is the mandibular condyle, followed by the coronoid process. In the present study, we have described the case of a 64-year-old Japanese man with an unusually large osteochondroma located on the internal angle of the mandibular body. Clinical, radiological, pathological, and treatment-related aspects are discussed with respect to the tumor origins.

CONCLUSIONS

In the medical literature, there have been few reports of large osteochondromas of the mandibular angle with no clinical symptoms.