What is the cause of oral leukoplakia?

Oral leukoplakia at this stage there is no particularly clear cause, oral leukoplakia has certain risk factors, that is, what factors can promote the occurrence of leukoplakia; smoking is the most obvious factor, to the current stage of the results of the study, liquor is also to pay attention to, there are other stimuli, such as hot food, long-term consumption of irritating food will also lead to inducing factors.