Modality-specific quantitative radiologic characterization of diffuse sclerosing osteomyelitis of the mandible: a pilot study

Abstract

Diffuse sclerosing osteomyelitis (DSO) of the mandible is a rare chronic inflammatory disease characterized by recurrent painful swelling and trismus. While advanced stages are known to show radiographically evident bone sclerosis, objective quantitative imaging criteria remain poorly defined. This study aimed to characterize modality-specific radiological features of DSO using intra-individual side-to-side comparison of bone density and cortical thickness. This single-center retrospective study included 22 patients treated for DSO between 2010 and 2021. Pre-treatment panoramic radiographs were available for all patients, CT datasets for 6 patients, and CBCT for 3 patients. Bone density was quantified using relative grayscale values in panoramic radiography, Hounsfield units (HU) in CT, and gray values in CBCT. Cortical thickness was measured on CT using standardized regions of interest, with contralateral-side comparison. Two blinded observers performed all measurements. Quantitative analysis demonstrated significantly higher bone density on the affected side in panoramic radiography and CT (panoramic: 46.0 ± 4.0% vs. 39.0 ± 3.6%, p < 0.001; CT: 1220.9 ± 215.8 HU vs. 1108.0 ± 163.9 HU, p = 0.01). In the three available CBCT datasets, descriptively higher gray values were observed on the affected side. CT analysis revealed significantly increased cortical thickness (5.63 ± 0.96 mm vs. 3.86 ± 0.75 mm, p = 0.04). A blurred inferior alveolar nerve canal was consistently observed on panoramic radiographs. Quantitative side-to-side assessment provides an objective radiological description of DSO and may support imaging assessment when interpreted together with clinical and histopathological findings. In this selected cohort, DSO-affected regions showed relative densification, cortical thickening in the available CT examinations, and blurring of the inferior alveolar nerve canal on panoramic radiographs.