SalivaSense 2.0: Multiplex cfDNA‑cfRNA Epigenome Signatures Enabling Pico‑Stage Oral Squamous Cell Carcinoma Detection, Validation Frameworks and Translational Pipelines

Background: Oral squamous cell carcinoma (OSCC) is characterized by a high mortality rate primarily because it is often diagnosed at an advanced stage, creating a profound global survival disparity. Early detection is paramount, yet a significant screening gap persists, especially in community and low-resource dental settings. This review articulates the case for SalivaSense 2.0, a conceptual framework designed to transform routine saliva sampling into an ultrasensitive multiplex liquid biopsy capable of detecting the disease at its nascent, "pico-stage".Main Body: The core innovation of SalivaSense 2.0 lies in the synergistic integration of stable cell-free DNA methylation signatures with dynamic cell-free RNA transcriptional profiles. This dual-analyte approach generates a comprehensive epigenomic fingerprint that can characterize tumorigenesis at its earliest detectable stages. The proposed assay is built on an automated microfluidic cartridge for highly efficient nucleic acid isolation from saliva. Downstream analysis employs advanced technologies like nanopore sequencing and electrochemical nanobiosensors. This system is unified by a sophisticated artificial intelligence pipeline that uses molecular barcoding and neural networks to suppress sequencing errors and computationally mitigate biological noise from confounders such as tobacco use, periodontal inflammation, and the oral microbiome. This achieves an exceptionally low detection limit, enabling the identification of minute cancer signals. The framework also delineates a complete translational pathway, from rigorous analytical and clinical validation benchmarks to the development of accessible point-of-care devices, including smartphone-linked readers and simplified sample logistics.Conclusion: While significant challenges in clinical validation, global data harmonization, and demonstrating economic feasibility remain, overcoming these obstacles is essential. Successfully translating this technology from the laboratory to the front lines of care could decisively shift OSCC management from reactive surgical intervention toward proactive, saliva-based preventive screening, dramatically improving patient outcomes worldwide.