Oral potentially malignant disorders (OPMDs): An overview

Oral potentially malignant disorders (OPMDs) represent a wide range of oral lesions and conditions that carry a variable risk of malignant transformation to oral squamous cell carcinoma (OSCC). Clinically, the majority of OPMDs present as white and/or red lesions. Oral leukoplakia is one of the most common OPMDs. The reported global prevalence of OPMDs is 4.47%, although there is considerable variation between different geographical regions. One of the most serious consequences of OPMDs is malignant transformation to OSCC, with approximately 7.9% of OPMDs progressing to OSCC. The risk of malignant transformation varies substantially among different OPMDs, with proliferative verrucous leukoplakia having the highest malignant transformation rate at 49.5%, followed by oral erythroplakia at 33.1% and oral leukoplakia at 9.5%. Although the presence and grade of oral epithelial dysplasia (OED) are strongly associated with the risk of malignant transformation, we currently lack an established tool that can accurately identify OPMDs at high risk for such outcomes.This book chapter aims to provide a general introduction to OPMDs and their epidemiology, followed by a discussion of associated etiological factors, a proposed model of molecular pathogenesis, diagnostic approaches, common treatment modalities, and prognostic factors for oral leukoplakia.