Faculty receive patent for aligner measurement method

A collaborative research endeavor between the Division of Biomaterials, the College of Science and Engineering and the Division of Orthodontics led to a patent for two School of Dentistry researchers.

Alex Fok, PhD, MSc, professor and director of the Minnesota Dental Research Center for Biomaterials and Biomechanics, and Brent Larson, DDS, MS, professor and director of the Division of Orthodontics, were awarded U.S. Patent No. 12,352,557 for “Orthodontic Aligner With Strain Measurement Features, And Methods Of Making And Using The Same.”

“The patent is issued for the use of fluorescent digital image correlation (an optical strain gauge method) to measure the surface strains on orthodontic aligners so as to monitor their biomechanical performances in situ,” explained Fok. “A unique feature of the proposed method is the use of fluorescent, instead of visible, speckles to maintain the aesthetic of the aligners. This will allow the method to be used clinically.”

Instead of simply making predictions, “this innovation gives us the ability to see how the aligner is actually performing in the patient’s mouth,” Larson explained.

The value of an “in situ” monitoring is beneficial from a clinical and a research perspective. This method can potentially give us the ability to measure how treatment is proceeding in real time, allowing adjustments to make treatment efficient for each individual patient,” Larson explained. This allows for better planning, with fewer corrections needed.

The process of getting an approved patent was long, and included quite a bit of hard work: the researchers first tested the use of digital image correlation using visible speckles, before moving to the more clinically-friendly fluorescent method. “From the initial disclosure to the final patent being issued took several years,” explained Larson.

And their work has already paid off. “We have since demonstrated a direct correlation between aligner surface strains and the tooth forces aligners produce, lending further support to the legitimacy of our method,” Fok explained.

Moving forward, the team hopes to further refine the aligners made with fluorescent speckles until they are as effective as those with visible speckles. This will allow their patented method to be used frequently and simply in the clinical setting. “We would like to continue to develop the technique, to make it efficient and patient friendly.”

As they move forward, Fok and Larson are excited about what the future brings—for this project and for others.

“This is just one step in our attempts to improve patient care through the use of advanced technology and innovation,” Larson reflected. “This is what happens in the unique environment that exists in the University setting that brings clinicians and engineers together.”