Patients with head and neck cancer will experience alteration of oral anatomy and physiology caused by the disease and the treatment required. Despite the implied effects on the dynamics of mastication, objective studies have not been conducted to evaluate masticatory function of these patients. Masticatory performance and swallowing threshold performance were evaluated with Frito corn chips as the test substance. Edentulous patients treated for cancer demonstrated deficiencies in both tests. Masticatory performance and swallowing threshold performance improved with prosthodontic rehabilitation but this improvement was less than with comparable controls. Techniques to evaluate masticatory factors such as dentition, dentures, biting force, temporomandibular joint status, range of motion, and saliva are suggested.