Scarring can be caused by loads of things, an infection such a tuberculosis, etc, most importantly stop smoking......There is no point sitting there worrying with a *** in your mouth....this has frightened you and you should give up for your future health as smoking does cause cancer....read the box...Hopefully you wont develope cancer....you have a much better chance if you give up.....
I know some people get lung cancer without ever smoking, but why give the disease a chance, put yourself first and be healthy....take care JanieB