Introducing Equivalent and Threshold Doses in the Assessment of Medication-Related Osteonecrosis of the Jaw Risk: Insights from a Descriptive Study in Iran

Purpose: To investigate the clinical characteristics and risk factors associated with medication-related osteonecrosis of the jaw (MRONJ) and to introduce two metrics—equivalent dose and threshold dose—as predictive risk assessment tools. Methods: This retrospective study reviewed 193 patient records from Shahab Clinic and the Oral Medicine Department of Mashhad Dental School (2017–2023). Patients were categorized into MRONJ stages (0–3) and an "at-risk" group. Data on demographics, comorbidities, clinical presentations, and detailed medication profiles were analyzed. Equivalent dose was standardized to four years of oral alendronate use, and threshold dose provided a cumulative risk cut-off. Statistical analyses( T-tests, ANOVA, Chi-square tests,.) were applied . Results: MRONJ was identified in 40.4% of cases, while 59.6% were classified as at-risk. Advanced stages were significantly associated with higher equivalent doses, prolonged medication use, and key risk factors, including oncologic diseases, medication type and route of administration, comorbidities, age, and surgical interventions such as extractions and ill-fitting dentures (p < 0.001). The novel metrics demonstrated strong predictive value, with higher equivalent doses correlating closely with MRONJ severity (R = 0.46, p < 0.001) Conclusion: This study offers critical insights into MRONJ risk stratification, highlighting the cumulative impact of medication dose alongside clinical risk factors. The introduction of equivalent and threshold doses represents a transformative advancement in MRONJ risk prediction, enabling precise prevention strategies and guiding clinical management toward standardized care protocols.