Our Doctor

RTHiller_cropDr. Dennis C. Hiller started his first specialty of orthodontics practices in Conway and Berlin in 1983. Over the past three decades, he has opened practices in the communities of Littleton, Conway, Plymouth and St. Johnsbury, VT. Dr. Hiller is passionate about his work and is known for his wonderful sense of humor, quality treatment and warm personality.

“The most rewarding part about devoting my professional life to orthodontics is that I have the privilege of improving a person’s confidence and self-esteem through their new smile,” Dr. Hiller says.


He resides in Thornton, New Hampshire and enjoys being involved in his community and church almost as much as spending time with his family. Dr. Hiller also enjoys golfing, viticulture, hiking and boating. He and Pat, his wife of 44+ years, have four children - Bryan and wife Miki, Matthew and wife Breanna, Kate and husband Dan, and Allison. He also has four adorable grandsons, Brayden, Tanner, Hudson and Jacob and five beautiful granddaughters, Payton, Abigail Lily, Macklynn and Blakeley (thousands of pictures available!). A northern New Hampshire resident by choice, Dr. Hiller has been an involved community member serving on many boards and committees over his career. He currently serves on the Advisory Board for the Ham Foundation as well as the board of the North Country Investment Council.

As a very involved member of his professional associations, he has served as Trustee to the New Hampshire Dental Society; President of the Northeastern Society of Orthodontists; Chairman of the Council on Governmental Affairs of the American Association of Orthodontists (AAO) and is the current Speaker of the House of Delegates of the AAO.


Dr. Hiller was born and reared in Nanticoke, a small town in northeastern Pennsylvania.  He attended Rensselaer Polytechnic Institute where he earned a Bachelor of Science in Biology; Temple University School of Dentistry where he earned both a Doctor of Dental Surgery (1981) and a Master’s of Science in Dentistry and Certificate of Specialization in Orthodontics (1983).

Continuing Education

By participating in more than double the required hours, Dr. Hiller is able to stay abreast of all the developments and provide the most advanced care possible. His memberships make it possible for him to continue his education and grow in his knowledge and skill as an orthodontist. He is currently enrolled in the Master's Clinician Program with Invisalign. Dr. Hiller is a frequent lecturer to local dentists and hygienists also.

“When I receive wedding and graduation photos as well as thank-you notes from both current and past patients, it reminds me of the impact I have been able to make on their lives. And for that, I am truly grateful.” - Dr. Dennis Hiller

Our Locations

Conway, NH
127 Main, Street

Littleton, NH
175 Cottage Street

Plymouth, NH
15 Town West Road

St. Johnsbury, VT
161 Western Ave