Differential diagnosis between oral squamous cell carcinoma and osteomyelitis through mandibular canal changes on panoramic radiographs

Differentiating between oral squamous cell carcinoma (OSCC) and osteomyelitis (OM) through imaging is essential due to the overlapping clinical and radiological presentations of these conditions, complicating diagnosis. This study assessed the adjunctive diagnostic value of mandibular canal–related radiographic features on panoramic radiographs to aid in differentiating OSCC from OM, and to propose a simple and efficient approach for general dental practitioners. A total of 166 panoramic radiographs from patients with histopathologically confirmed OSCC (n = 83) and OM (n = 83), involving the mandibular third molar region and/or retromolar trigone with bone destruction, were retrospectively analyzed. The border changes of the mandibular canal and adjacent sclerosis were assessed on the panoramic radiographs. Statistical analysis was performed using chi-squared tests to determine the significance of differences between OSCC and OM for each radiographic feature. Receiver operating characteristic analysis was also performed to evaluate the discriminative performance of a composite scoring model for distinguishing OSCC from OM, in which one point was assigned for each high-risk imaging feature for OSCC. Destruction of the borders of the mandibular canal was significantly more frequent in OSCC cases (P < 0.001), while border thickening of the mandibular canal and adjacent sclerosis were more commonly associated with OM (P < 0.001). Additionally, a composite scoring model based on these imaging features demonstrated high discriminative performance, with an area under the curve of 0.92, further supporting differentiation between OSCC and OM. The changes in the mandibular canal, including border destruction, border thickening, and adjacent sclerosis, observed on panoramic radiographs may serve as useful adjunctive indicators for differentiating OSCC from OM. Recognition of these features on routine panoramic imaging may help guide appropriate further diagnostic evaluation, particularly in clinical settings where immediate access to three-dimensional imaging is limited.