<p>Objectives: Osteosclerosis and a high bone mineral density (BMD) have been proposed as risk factors for medication-related osteonecrosis of the jaw (MRONJ). In the present study, we measured the alveolar BMD (al-BMD) of teeth indicated for extraction on dental radiographs using BMD analysis software and investigated the relationship between al-BMD and MRONJ.</p><p>Materials and Methods: We measured al-BMD on dental radiographs using BMD analysis software (Bone Right) in 100 bone-modifying agent (BMA)-treated patients who visited our department for tooth extraction between November 2020 and May 2023. Fifteen patients treated with BMA for more than 4 years underwent tooth extraction 2 months after their cessation.</p><p>Results: In 100 patients who underwent tooth extraction, only one patient on high-dose anti-resorptive agents (ARAs) developed MRONJ. al-BMD was significantly higher in MRONJ patients than in non-MRONJ patients. No significant change was observed in al-BMD before and 2 months after the cessation of BMA.</p><p>Conclusion: Patients who developed MRONJ after tooth extraction had higher al-BMD before tooth extraction, and a relationship between MRONJ and osteosclerosis cannot be ruled out. On the other hand, al-BMD did not change before and after the cessation of BMA, and MRONJ did not occur in patients treated with low-dose ARAs, suggesting that the cessation of BMA is not necessary. (J Osaka Dent Univ 2024; 58: 153-164)</p>