Dr. Marshall has been in private practice in Chicago and was also a faculty member at the Northwestern University Dental School before coming to the University of Iowa. He is an adjunct associate professor in the Department of Orthodontics.
Participates in the preparation of residents for board certification in orthodontics.
Dr. Marshall's research interests include facial growth and development. He participates in the scholarly activity of the orthodontic department as a regular member of resident thesis committees. He authors or co-authors publications submitted from resident and departmental research.
Dr. Marshall is a fellow of the American College of Dentists and a member of Omicron Kappa Upsilon. He served as director of the Illinois Society of Orthodontists from 1998-2003 and as director of the Midwestern Society of Orthodontists (MSO) from 2000-2008. He received the Earl E. Shepard Award from the MSO in 2008. He is a member of the E.H. Angle Society of Orthodontists and the College of Diplomates of the American Board of Orthodontics. Dr. Marshall served on the Mentor Committee of the American Board of Orthodontics College of Diplomates from 2001-2003 and served as councilor for the same organization from 2005-2009. He served as a delegate of the American Association of Orthodontists House of Delegates from 2002-2010. He is a member of the editorial board of the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist. He currently serves as a consultant examiner to the American Board of Orthodontics.