Diagnostic adjuncts for oral potentially malignant disorders such as leukoplakia or erythroplakia can aid the clinician in triaging abnormal lesions and facilitate both biopsy site selection and surgical management. No adjuncts replace gold standard biopsy and histopathological examination, and their optimal use requires training and experience. This article covers the potential applications, both in primary and expert settings, of adjuncts, such as tissue autofluorescence, toluidine blues staining, and cytopathology. It covers new and emerging adjuncts such as confocal microscopy, liquid biopsy, oral microbiome testing, and the role of artificial intelligence. Incisional biopsy site selection and techniques will also be discussed.