Group 1 (Pre-Radiation) Subjects who are currently undergoing or scheduled to undergo treatment with radiotherapy with or without chemotherapy (induction or concurrent) with intent to eradicate the malignancy. Treatment will include the following: 1) primary or nodal disease adjacent to (within 2 cm) the mandible (i.e., likely to receive a dose of at least 50 Gy to some portion of the mandible volumes) and 2) >60% probability of survival for 3 years after treatment.