Diagnostic Accuracy of Raman Spectroscopy for Oral Potentially Malignant Disorders: A Systematic Review and Meta-Analysis

<b>Objective</b>: The aim of this study was to summarize the accuracy and efficacy of Raman spectroscopy (RS) technology in identifying Oral Potentially Malignant Disorders (OPMDs). <b>Methods</b>: This systematic review was registered in PROSPERO (CRD420251124866). A literature search was conducted in databases including PubMed, Embase, and Web of Science from inception up to September 2025. The risk of bias of included studies was evaluated using the QUADAS-2 tool. Appropriate statistical techniques were applied to perform heterogeneity analysis, subgroup analyses, and calculation of pooled diagnostic efficacy indices. <b>Results</b>: A total of 12 studies involving 2810 samples were included. In the "OPMDs vs. Normal" group, RS achieved a pooled sensitivity of 0.84 (95% CI: 0.78-0.88), specificity of 0.90 (95% CI: 0.73-0.97), and AUC of 0.89 (95% CI: 0.86-0.91). In the "OPMDs vs. Oral squamous cell carcinoma (OSCC)" group, the pooled sensitivity was 0.89 (95% CI: 0.82-0.94), specificity was 0.91 (95% CI: 0.85-0.95), and AUC was 0.94 (95% CI: 0.91-0.96). Heterogeneity analysis revealed low heterogeneity in the "OPMDs vs. OSCC" group (I² = 22.8%) and moderate heterogeneity in the "OPMDs vs. Normal oral mucosa" group (I² = 58.9%). Subgroup analyses were performed: sample type exerted no significant impact on heterogeneity (<i>p</i> > 0.19), while Raman type (micro vs. fiber) showed potential to modulate diagnostic efficacy, micro-Raman had higher sensitivity (0.916 vs. 0.811), and fiber-Raman had better specificity (0.917 vs. 0.843). No significant publication bias was observed (Egger's <i>p</i> > 0.3). <b>Conclusions</b>: Raman spectroscopy is an effective and reliable tool for screening and differentiating OPMDs.