the cure for bruxism can be many and varied depending on the cause.
Once the cause has been removed then self-healing will take place whether fasting or not, but the fast will accelerate this healing process.
Remove the cause (once discovered) and healing will take place, including the reduction of your jaw muscles, which when not overworked will reduce in size over time.
Please do not confuse the word "starvation" with "fasting" as explained in my previous post.