Welcome to HCM
I went through your history & would like to tell you that your problem seems to be due to your wisdom tooth.I would like to ask you:-
-has your wisdom tooth fully erupted?
-do you experience difficulty in opening mouth??
-do you have habit of smoking??
-do you have difficulty in protruding tongue??
-is there blanching of oral mucosa??
If its related to wisdom teeth then you get it removed because its not of much use.
If you have smoking & other habits then it can be premalignant lesion.
White line is linea alba & is normal variant occur due to cheek biting