I have a small white spot behind my lower right molar, i don't have wisdom teeth. it's painless as of now. no red border or inflammation. ?

Callous: this area often gets hyperkerstized or calloused due to chewing. Can be worse if you smoke. Get it checked

Normal?: Having a white spot in the area behind your lower molars may be a normal abnormality. The spot can be scar tissue, lichen planis, small growth, cancerous lesion, or many other leukoplakic forms. It is a very common site for trama from eating, etc. Your dentist may have seen it and noted the site. I would see your dentist and express your concern. A simple brush biopsy may confirm the type.