Specific Aim 2: Evaluate the effect of Complete Decongestive Therapy (CDT) provided in an outpatient setting or a home-based program in reducing lymphedema in patients previously treated with surgery and/or radiation therapy (± chemotherapy) for oral cavity and oropharyngeal cancer at 1, 3 and 6 months follow-up. Patient characteristics, treatment variables, and the health care environment will be analyzed as possible explanatory variables that influence the effect of lymphedema treatment.