Dr. Duffner grew up in Thornton, went to school in Chicago and has lived in the south suburbs all of his life. In 1988 he married his wife Rosemary McGrath, MD., who is a family practitioner in Mokena. They have three children, Eileen, Brendan and Caitlin.
He earned his degree in physics from Loyola and his degree in dentistry from the University of Illinois. He has been practicing with Dr. Kreuz at their dental office in Homewood since 1985.
Dr. Duffner is a passionate bicyclist and enjoys cycling to work from Frankfort. He bicycles for the National MS Society every year to help raise funds to fight Multiple Sclerosis. If you would like to join the fight and help raise funds for his 2023 ride, please click here to help him reach his goal of raising $10,000 towards research to eliminate MS.
In 2013, Dr. Duffner organized a ride to benefit Mercy Housing, a faith based nationwide non-profit that provides homes and services to homeless veterans, single parents, people with special needs and many others. He and five friends bicycled 3667 miles coast to coast in six weeks raising over $60,000 and spreading the word about Mercy Housing.