Comparative Evaluation of Salivary Malondialdehyde Levels in Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma

Background: Oxidative stress is implicated in the pathogenesis of oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC). Malondialdehyde (MDA), a product of lipid peroxidation, may serve as a salivary indicator of oxidative stress. Objective: To estimate and compare salivary MDA levels among patients with OSCC, oral leukoplakia (OL), oral submucous fibrosis (OSMF), and healthy controls. Materials and Methods: This observational, cross-sectional, comparative study included 80 participants, with 20 participants in each group. Unstimulated whole saliva was collected and MDA was estimated using a thiobarbituric acid reactive substances-based spectrophotometric method. Results: Mean salivary MDA optical density was highest in OSCC (0.6774 ± 0.1898), followed by OL (0.2922 ± 0.2324), OSMF (0.2032 ± 0.1954), and controls (0.0299 ± 0.0203). One-way ANOVA showed a significant difference among groups (F=46.6122, p=0.0001). Tukey's post-hoc analysis showed significant differences between OSCC and each other group, OL and control, and OSMF and control; the difference between OL and OSMF was not significant. Conclusion: Salivary MDA levels were significantly elevated in OPMDs and OSCC compared with healthy controls. The findings support an association between increased lipid peroxidation and these oral disorders; however, the diagnostic and prognostic utility of salivary MDA requires validation in larger prospective studies.