Deep indentation in cheek after SMAS - what is it and how can it be treated? (photo)

1/8/14 I had a SMAS. Two days post-op I developed a seroma on the left side of neck, it was drained four times. The second week in February I developed a deep horizontal-ish indentation on my left cheek. The indentation, tightness and discomfort in my neck and cheek increases with turning my head to the right. My PS said he has never seen anything like this before. I was given a steroid injection, 2 1/2 weeks ago without any relief of symptoms. What is the indentation and how should it be treated?