The primary aim of this study was to assess longitudinal radiographic changes in medication-related osteonecrosis of the jaw (MRONJ) using the expanded Composite Radiographic Index (eCRI) and to determine their associations with clinical disease severity and treatment outcomes. Secondary objectives included identifying individual radiographic parameters most strongly associated with clinical staging.

In this single-center retrospective cohort study, MRONJ patients were monitored using cone-beam computed tomography (CBCT). Clinical severity was assessed using a seven-subclass scoring system (K0–K6), summarized as the Clinical Score (CS). Radiographic changes were evaluated using the eCRI. Statistical analyses included linear mixed-effects modeling to account for longitudinal data, Spearman’s rank correlation for clinical-radiographic associations, and multivariate linear regression to identify factors associated with outcomes. Significance was set at p < 0.05.

A total of 102 CBCT scans from 28 patients were analyzed over a mean follow-up of 17.2 ± 10.7 months. Linear mixed-effects models revealed that lytic changes ( p = 0.002) and sequestration ( p = 0.034) were significantly associated with advanced AAOMS stages. The combined presence of lytic changes and sequestration showed a significant positive correlation with higher Clinical Scores ( p = 0.013). Conversely, no significant associations were found for sclerosis or periosteal reaction ( p > 0.05). Multivariate analysis identified baseline eCRI as the only factor independently associated with radiographic outcome ( p < 0.001).

The eCRI effectively captures longitudinal radiographic alterations in MRONJ. No statistically significant association between sclerosis or periosteal reaction and prognostic outcomes was observed in this cohort, although the limited sample size may have reduced statistical power. In contrast, the coexistence of lytic changes and sequestration served as a robust indicator of clinical severity. Persistence of these findings may reflect a tendency toward prolonged disease activity and may justify closer reassessment during follow-up. Integrating radiographic findings with clinical assessment may enhance accuracy in monitoring progression and support individualized treatment planning.