The Application and Validity of a New Composite Radiographic Index for Patients with Osteonecrosis of the Jaws

<b>Background/Objectives</b>: This study aims to determine the validity of a recently developed and published index (the modified Composite Radiographic Index-CRIm) as an indicator of disease gravity and progression in the CBCT scans of patients with medication-related osteonecrosis of the jaw (MRONJ) and to detect possible correlations between the radiologic findings and clinical staging of the disease. <b>Methods</b>: This study included 43 MRONJ patients with CBCT scans from the School of Dentistry of National and Kapodistrian University of Athens, approved by the Research Ethics Committee. Clinical staging (0-3) was provided based on AAOMS 2022 guidelines. A total of 52 CBCT scans were analyzed, with maxillae and mandibles evaluated separately when both were involved. Two independent observers assessed eight radiologic features, including lytic changes, sclerosis, periosteal reaction, sequestration, non-healing extraction sockets, and other findings (sinus involvement, inferior alveolar canal involvement, and jaw fracture). The CRIm was applied to quantify osseous changes, scoring each feature (0 (absent), 1 (localized/single), 2 (extensive/multiple)), yielding a range of 0-12. For the statistical analysis, Fisher's exact test and Spearman's correlation coefficient were used. <b>Results</b>: Clinical Stage 1 consisted of 19 jaws, Stage 2 consisted of 16 jaws, and Stage 3 consisted of 17 jaws. No affected jaws were recorded with Stage 0. A statistically significant correlation between the clinical stage and lytic changes, sequestration, and inferior alveolar canal involvement was found (<i>p</i>-value < 0.05). Extensive lytic changes, sclerosis, sequestration, periosteal bone formation, and inferior alveolar canal involvement were mostly observed in clinical Stage 3. Furthermore, a statistically significant correlation between clinical stage and CRIm classification was found (rho = 0.446; <i>p</i>-value < 0.001). <b>Conclusions</b>: The CRIm tends to increase as the clinical stages of MRONJ advance, suggesting a correlation between them.