Hi.. Can understand your concern.. As per your complain a ball like lump near the jawline under the skin is most probably an enlarged lymph node.. An enlarged or swollen lymph node most commonly occurs due infection in any close area of the body like in case of lump under the jaw the swollen lymph node can be due to any deeply infected tooth, deep seated infection in gums, inflamed gum flap over the erupting or impacted wisdom tooth, salivary gland infections, throat and ear infections. Many a times the infections in other parts of the body are carried through the lymph and carried to the distant lymph nodes. The infecting organisms settle in the lymph nodes and cause inflammation leading to swelling. Other reasons can be swelling in salivary glands due to any obstructions in the ducts or any infections in the salivary glands or any cysts or tumours in the glands.. You need not to worry about it as when the infection will settle down they will also reduce in size,just take care that if you have any infected tooth or any other kind of infections as i explained above you should consult the appropriate doctor/dentist and get treated.. Hope your query is solved.. If you find the answer helpful please write a positive review and click on find this answer helpful as a token of appreciation.. Thanks and regards.. Dr.Honey Nandwani Arora.