Tom Deahl earned a D.M.D. from Southern Illinois University at Edwardsville's School of Dental Medicine, and a Ph.D. in Radiation Biology and certificates in Oral and Maxillofacial Radiology and in Oral Pathology from The University of Iowa. He has practiced general dentistry in downstate Illinois, and has taught maxillofacial radiology at both SIU Edwardsville and UT Health San Antonio. He has served as staff lecturer for INR, a nonprofit health professions continuing education group in Concord, California. He is a diplomate of the American Board of Oral and Maxillofacial Radiology.