Timing and Associated Factors to Formation and Detection of Sequestrum in Patients With Medication‐Related Osteonecrosis of the Jaw

Objective This study investigated the timing of sequestrum formation and detection, and associated factors with medication‐related osteonecrosis of the jaw (MRONJ) among patients who had undergone conservative management. Methods This study retrospectively analyzed data from 214 patients with MRONJ who underwent conservative management after invasive dental procedures between January 2014 and July 2025. The time to sequestrum detection was measured from the dental procedure to sequestrum development. Demographic and clinical variables, including primary disease, comorbidities, medication type and duration, and medication cessation, were investigated. Results Among 101 included patients, the mean time to sequestrum formation and detection was 6.82 ± 5.44 months. Patients with osteoporosis (6.31 ± 5.31 months) developed sequestra significantly earlier than those with malignancy (9.99 ± 5.35 months) ( p = 0.018). The time to detection was longer in patients with comorbidities compared with those without comorbidities (8.21 ± 5.30 vs. 5.98 ± 5.40, p = 0.045). Notably, there was a significant difference depending on whether medication was discontinued (5.61 ± 4.93 vs. 9.82 ± 5.56 months, p < 0.001). Multivariate analysis identified medication cessation as the only independent factor affecting sequestrum detection time ( p = 0.002). Conclusions Sequestra typically formed and were detected at approximately 6–7 months, and continuation of medication after invasive dental treatment was associated with delayed sequestrum development.