Without a look at the clinical picture of the legion it would be difficult to give a rational suggestion about the white patches that you are suffering from. It's good that you do not smoke but smoking is not the only reason for such patches. A detailed clinical history about other habits and your dietary schedule need to be taken to aid in the diagnosis. Presence of irregularly positioned or sharp teeth also needs to be checked. Some laboratory test might also be required. A proper clinical check up with an oral pathologist will be the next prudent step to arrive at the right diagnosis so that the right treatment can be instituted if required. Regards.