Evaluation of cortical mandibular bone in patients with oral squamous cell carcinoma.

Abstract

The aim of the study was to evaluate the mandible cortical bone changes in patients with oral squamous cell carcinoma (OSCC). Twenty patients who underwent some mandibular bone removal as part of the treatment of OSCC had bone samples collected in two parts: in the proximity of the tumor (BPT) and in the surgical margin (BEP). Cortical microarchitecture was analyzed trough micro-computed tomography, together with texture analysis, followed by microcrack evaluation in histological sections and gene expression of RANK, RANKL, OPG, and sclerostin by quantitative polymerase chain reaction. Bone surface was higher in BPT (0.005±0.002 vs 0.004±0.002, p=0.01) compared with BEP. In BPT, the subset of patients without bone invasion presented higher anisotropy (0.83±0.07) compared with the ones with bone invasion (0.70±0.14) (p=0.04). RANK, RANKL, OPG, and sclerostin were found to be downregulated in the majority of cases in both parts. There were significant correlations between the parameters of microarchitecture and gene expression analysis (p<0.001 to p<0.05), most of them related with OPG levels. The cortex in the mandible in the proximity of the tumor reveals more bone surface than the bone in the surgical margin, and the tumor invasion causes a decrease in anisotropy. RANK, RANKL, OPG, and sclerostin are downregulated in mandible, in both parts analyzed. Correlation tests revealed the association between cortical thickness, bone surface, anisotropy, porosity, bone mineral density, and OPG levels. The mandible cortical bone microarchitecture changes in the proximity of the squamous cell carcinoma lesion.