Role of optical imaging in oral cancer and oral potentially malignant disorders: implications for oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic, potentially malignant disorder characterized by progressive stromal fibrosis and epithelial atrophy, leading to functional loss and an increased risk of malignant transformation. Areca nut consumption remains the principal etiological factor in South and Southeast Asia. Despite its distinct clinicopathological features, OSF assessment relies largely on clinical examination and invasive biopsy, underscoring the need for non-invasive approaches capable of interrogating tissue structure and composition. Optical imaging (OI) technologies, including confocal-based imaging, optical coherence tomography (OCT), narrow-band imaging (NBI), and Raman spectroscopy (RS), have been widely investigated in oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC). However, the applicability of OI to OSF remains undefined. The aims of this narrative review are to: 1) critically synthesize current OI evidence in oral mucosal disease, and 2) evaluates the biological plausibility and technical limitation of applying these modalities to OSF from a pathobiology point of view. Highlighted in this review are the cellular and extracellular matrix alterations that may generate measurable optical signals and the paucity of OSF-specific validation studies, in addition to discussing constraints related to imaging penetration depth and disease grading, and outlining future research directions, including extracellular-matrix-focus optical biomarkers and artificial intelligence-assisted analysis. Collectively, this work positions OI in OSF as a hypothesis-generating and exploratory domain requiring rigorous, pathology-correlated investigation before clinical translation.