Use of the Fractal Dimension to Differentiate Epithelium and Connective Tissue in Oral Leukoplakias

SIMPLE SUMMARY: Dysplasia grade identification is the only consolidated factor by which to evaluate the risk of developing oral cancer from oral leukoplakia lesions. An objective manner to determine dysplasia grade is still lacking and this has prompted our research. Our findings can help dentists and pathologists to predict oral leukoplakia prognosis with a non-invasive, easy-to-use tool, using the fractal dimension as invariant. ABSTRACT: Background: Oral leukoplakia (OL) is considered one of the most common potentially malignant oral disorders (OPMD), with a verified increased risk of developing oral cancer. The identification of the dysplasia grade (low–high) is the only consolidated factor used to evaluate this risk. The objective of this study was to verify the role of the fractal dimension (FD) in assessing this dysplasia. Methods: To begin, 29 OL and 10 normal oral mucosa (NOM) biopsies were retrieved for FD analysis of the epithelial (dime) and the connective (dimc) tissue. Results: In the OL group, the median value of dime is higher (1.67, IQR = 0.12) than for the NOM group (1.56, IQR = 0.08), with statistically significant differences (Wilcoxon test, p = 0.0031). There were no differences in relation to dimc. Significant differences were observed between the non-dysplasia vs. high-grade (p = 0.0156) and low-grade vs. high-grade (p = 0.0049) groups. No significant differences were identified in relation to dimc for the different degrees of dysplasia. For a cut-off point of 1.44 of dime, a specificity of 96.6% was obtained, a sensitivity of 100%, and an AUC = 0.819 (p = 0.003). Conclusions: FD at the level of the epithelium may be used as a diagnostic tool in OL.