FACS simply indicates that he is a Fellow of the American College of Surgeons (i.e. a board-certified surgeon). It means nothing in terms of cancer expertise.

Here's a link to the doctors at the UT Cancer Institute in Knoxville. As Anne-Marie says above, you'll want to see an oral/maxillofacial surgeon. They do have the cancer expertise: http://www.utmedicalcenter.org/cancer_institute/physicians_and_caregivers/ci_ut_physicians/

And here's the info for the head/neck cancer service: http://www.utmedicalcenter.org/cancer_institute/cancer_medical_services/head_and_neck/

All the best --
Leslie