Obviously you need to check with your doctor, but sounds like lymphedema to me. Your lymph fluid doesn't have anywhere to go anymore now that you've had lymph nodes removed, so it pools in places like the jaw line. My doctor referred me to Occupational Therapy to deal with the lymphedema I was experiencing - I didn't even realize how swollen I was until I had my first manual lymphatic drainage massage - there were instant results. My speech even improved - lymphatic fluid can also pool in your tongue and inside of your cheeks. My OT taught me how to do the massage technique myself, and now when I see that my jaw line is puffing up or my cheeks are starting to get thick, I can manage it on my own.