Non-Invasive Techniques for Detection and Diagnosis of Oral Potentially Malignant Disorders

Oral squamous cell carcinoma (OSCC) is the most common oral and maxillofacial malignancy, and its morbidity and mortality rates are still high in most countries. Oral potentially malignant disorders (PMDs) are used to refer to a heterogeneous group of conditions that are characterized by increased risk for malignant transformation to OSCC. Currently identified oral PMDs include leukoplakia, erythroplakia, palatal lesions associated with reverse smoking, oral lichen planus, oral submucous fibrosis, actinic keratosis, and discoid lupus erythematosus. The early detection and diagnosis of these lesions are important for cancer prevention and disease management. In recent years, there has been a growing and persistent demand for new non-invasive, practical diagnostic techniques that might facilitate the early detection of oral PMDs. The non-invasive detection techniques evaluated in this review are divided into four categories: vital staining with a solution that can be used as a mouth rinse or applied onto a suspected area of the mouth, light-based detection systems, optical diagnostic technologies that employ returned optical signals to reflect structural and morphological changes within tissues, and salivary biomarkers. Most of these techniques have shown great potential for screening and monitoring oral PMDs. In this review article, the authors critically assess these non-invasive detection techniques for oral PMDs. We also provide a summary of the sensitivity and specificity of each technique in detecting oral PMDs and oral cancer, as well as their advantages, disadvantages, clinical applications, and indications.