Our Orthodontics Team

Our Doctors/Faculty

Brent Larson, DDS, MS, Division Director

Brent Larson, DDS, MS, Division Director 
Dr. Larson received his dental degree from the University of Minnesota in 1981, completed a GPR in the Air Force in 1982 and practiced general dentistry until 1985. He received his Certificate and Master's degree in Orthodontics from the University of North Carolina in 1987. He spent three years as an orthodontist in the U.S. Air Force before joining the staff and faculty at the Mayo Clinic in 1990. At Mayo he served as Program Director in Orthodontics and received several "Teacher of the Year" awards. In 1996 Dr. Larson left Mayo for full-time private practice in Rochester, Minnesota, where he continues to practice one day a week. In 2004, he returned to full-time academics as Associate Professor and Director of Orthodontics at the University of Minnesota. He has written many scientific articles, contributed book chapters, and given many lectures in the U.S. and abroad. He recently received the Distinguished Dental Alumnus Award from the University of Minnesota.

Dr. Larson is a Past-President of the Minnesota Association of Orthodontists, the Midwestern Society of Orthodontists (MSO) and the American Association of Orthodontists (AAD). 

Thorsten Gruenheid

Thorsten Gruenheid, DDS, Dr med dent, PhD, MHA 
Associate Professor

Dr. Gruenheid received his training at the Universities of Mainz, Amsterdam, and Minnesota. He is certified by the American Board of Orthodontics and has lectured nationally and internationally on a variety of topics in orthodontics and oral biology. Dr. Gruenheid provides orthodontic treatment primarily to an underserved child and adolescent population at the University of Minnesota Orthodontic Faculty Practice.


John P. Beyer, DDS, PhD

John P. Beyer, DDS, PhD 
Clinical Associate Professor 
Dr. Beyer earned his Dental Degree, Certificate in Orthodontics and PhD from the University of Minnesota. After completing his graduate training Dr. Beyer was a fulltime faculty member for twelve years within the Division of Orthodontics. He spent time teaching at both the graduate and undergraduate level and was briefly appointed co-director of the graduate program in orthodontics. Dr. Beyer then went into private practice for five years, while still maintaining involvement in the graduate orthodontic training program through a part-time adjunct position. In 2014, he returned to fulltime academics at the University of Minnesota’s Division of Orthodontics and is currently the director of the Graduate orthodontic training program.

Amy Tasca, DDS, PhD

Amy Tasca, DDS, PhD 
Clinical Associate Professor and Holder, Robert J. Isaacson Chair in Orthodontics 
Dr. Tasca, originally from Winona, Minnesota, completed a six-year BA/DDS program at the University of Missouri Kansas City. After graduation, she practiced general dentistry in Breckenridge, Colorado and completed a teaching fellowship in Oral Surgery at UMKC. In 2012, Dr. Tasca returned to Minnesota to begin work on her PhD in conjunction with her Certificate in Orthodontics. At the completion of her residency program in 2018, she joined the University of Minnesota’s Division of Orthodontics as a full-time faculty member. 

Petra Bachour, DMD, MS

Petra Bachour, DMD, MS 
Clinical Assistant Professor 
Dr. Petra Bachour earned her DMD degree from the Harvard School of Dental Medicine. She then received her Certificate in Orthodontics and Master’s of Science degree from the University of Minnesota School of Dentistry. Dr. Bachour joined the faculty at the University of Minnesota Division of Orthodontics in 2022. She continues to practice orthodontics in the community.

Dr. Bachour has interest in emerging orthodontic technologies with a focus on digitally-driven orthodontics.

Our Residents

Class of 2024

Dr. Suzanne Anderson 
Dr. Nathan Caple 
Dr. Casey Ng 
Dr. Emilyn Asinas 
Dr. Robert Klabunde 
Dr. Deborah Liu

Class of 2025

Dr. Ryan Keesler 
Dr. Sara Schadeberg 
Dr. Kaimen Obeng 
Dr. Katherine Kucharyszyn 
Dr. E.Y. Masunaga 
Dr. Emerson Gonyea

Our Team

We know that our office is only as effective and as welcoming as the people who work in it, which is why we take pride in our friendly and well-trained team members! As a team, we are especially interested in making all our patients feel right at home! We put your needs first to achieve efficient and comprehensive treatment in a supportive and nurturing environment. We promise to speak candidly with you about possible treatments as well as any risks and associated costs of treatment, and how treatment can address your individual needs as a patient.

Our staff consists of team members with specialized training and multiple certifications, and each one of our team members has years of experience in treating patients with the highest level of care. We strive to stay abreast of the very latest in technology and advances by regularly attending continuing education courses and seminars.

Clinic Coordinator 

Clinic Supervisor

Faculty Practice Lead

Financial Coordinator 


Front Desk  

Dental Assistants