Lump on jaw can be there because of infected tooth. Impingement of some sharp food stuff can also lead to swelling of the jaw and can cause soreness. If it is present at the end of jaw, then it can be because of wisdom tooth eruption
. It can also be a canker sore
or can be there because of some pathology. Without clinical examination, it is difficult to give definite diagnosis. You have to visit your dentist
for evaluation and treatment. If it is because of infected tooth, then treatment is required for the infected tooth. If it is there because of impingement of some sharp food stuff, then it will regress on removal of sharp food stuff. Wisdom tooth eruption can lead to swelling of the jaws and gums and can lead to soreness. By the time, you visit your dentist, you can do warm saline rinses for some relief. If it is paining bad, then you can apply orajel
over it or can take otc pain medicines.