could be parotid calculus
There has been an increase of this type of lump found on that area of the head and your doc may not tell you this (He/She may not be aware) but check your cell phone usage. Could be a non-malignant tumor. Google cell phones and non-mal tumors of the face and neck and you will get more details than I can supply. I personally would use blue-tooth or speaker mode only (and do) and get checked for thyroid, para-thyroid, etc.
Hi there, im not sure, i could completely be missing the point but we have glands just under our jaw, like lumps of bone, one either side, one day when i was ill they were painful and thats when i discovered them, i was worried at first but my mum told me not to move them about and eventually the pain stopped. Im not sure if this has helped. If not then i suggest you get it checked at the doctors :)