Oral potentially malignant disorders (OPMDs) and oral epithelial dysplasia (OED) include a group of conditions that affect the oral mucosa with an increased risk of malignancy. Up to a third of OPMDs may transform to squamous cell carcinomas.  Tobacco (smoked and smokeless), E-cigarettes and, to a lesser degree, alcohol abuse, are strongly associated with most OPMDs. ^1,2  Most cases of oral epithelial dysplasia (OED) are associated with the use of tobacco (smoked and smokeless) or areca nut, alone / in combination, or (to a lesser degree) with alcohol abuse, but for many cases of OED etiopathogenesis remains unknow. ³ Areca nut chewing is the main etiological factor for oral submucous fibrosis 

A controversy over the role of HPV in proliferative verrucous leukoplakia (PVL) still exists, and Ki-67 positivity prevalence was also small.  On the other hand, DNA ploidy was found in almost all PVL lesions, while p53 positivity was found in only 27%. ⁴  HPV-associated oral epithelial dysplasia may cause by epithelial infection by high-risk HPV subtypes, usually type 16, although other types may be detected. ⁵