Get the Best Oral Lichen Planus Treatment in India Aishwarya Pillai Apr 6, 2023, Treatments Despite having a prevalence of 0.2-5% in the world population, oral lichen planus is one of the most common mucosal diseases. Depending upon the variant, the condition can also turn cancerous. The word lichen planus has been derived from Greek as well as Latin. Lichen is taken from the Greek word Leichen, meaning tree moss, while planus is taken directly from Latin, meaning flat even surface.