Dentist examining X-ray of patient's molars.
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The AI for dentists startup has set its sights on Seattle

  • Hope Reese
6/8/2022

The Seattle Study Club has partnered up with Overjet, the AI-for-dentists startup.

AI has been making inroads into medicine for some time: Over the last several years, many oncologists have adopted machine learning systems to help detect breast cancer, skin disease and other types of cancer. In the dental field, however, it’s a different story.

“There’s a whole host of scans that AI has been leveraged for, but dentistry has lagged [behind],” said Dr. Chris Balaban. Balaban is the vice president of clinical affairs for Overjet, a startup that hopes to bring AI to dentistry.

In May 2022, the Boston-based company was granted FDA clearance for its machine-learning software, which can help detect dental caries (cavities) and bone loss. This builds on its first FDA clearance, a year prior, for its AI-based Overjet Dental Assist, which helped measure bone levels in patients with gum disease, an affliction that can lead to tissue and bone loss. While companies like VideaHealth also harness AI in dental cavity detection, Overjet claims it is the only dental AI company to address both gum disease and cavities — which, according to the CDC, are the two greatest threats to dental health.

The new software, called Caries Assist, was built on a machine learning algorithm that was trained on millions of data points. Balaban says that one dentist can only look at so many X-rays over the course of his career — around 100,000, he estimates — and those include that dentist’s patients, in a specific demographic. But the algorithms have a much more expansive set of material to process.

“Tens of thousands of different dentists’ lifetimes of observations,” as he said. For example, “the model that can detect enamel, trained on 400,000 X-rays, is the equivalent of 160 years of a doctor looking at X-rays.”

When applied to analyze over 7,000 tooth surfaces, Caries Assist yielded an increase in cavity detection by 32%, the company said. (These numbers have not yet been independently verified.)

In addition to offering a subscription-service to large dental groups and insurance companies in the US, Overjet has partnered with the Seattle Study Club — the world’s largest network of dental professionals, with more than 250 dental groups worldwide. The groups get together monthly, to take a look at case studies and talk through various dental solutions.

“There’s always a good, better and best way to approach things,” Balaban said. Now, the SSC is using Overjet as part of its training. The club puts together clinical models, as part of a curriculum, and it will integrate the AI-based training so that dental practitioners can explore their product.

According to Balaban, there have been a few big moments in dental history, such as the transition from film X-rays to digital sensors. In his opinion, “AI is the next technical revolution in dentistry.” Balaban saw a “big bang of AI in dentistry” in 2021, in which machine learning was harnessed in 3D scanning and X-ray interpretation.

Balaban attributes the lag in adopting AI in dentistry to a generational gap, and a resistance to new technology. Loupes, for instance, which are magnifying glasses for dentists, are now used by all medical students, but were also slow to be adopted by an older generation.

“Old school guys didn’t practice like this — there were far more guys back then — they just had their own way of doing things,” Balaban said. But his job, he believes, is to convince them that the AI is here “to augment your clinical abilities and help you make decisions better than you already do.”

The tool is not meant to diagnose, but to help dental clinicians make “better decisions based on data that has never been quantified for them,” Balaban said. “The computer is putting together all of these data points to say ‘these are your choices,’ and for the patient to understand what we’re talking about.”

As what he calls a “patient literacy tool,” Overjet also offers visual graphics that can better explain to patients what’s really going on.

Dental problems are often complex, Balaban said. “Not all cavities are created equal. If it’s in the enamel, we could wash it, but if it’s in the next layer, you need to treat it.” With Overjet, you’re getting a prediction based on 500,000 examples of similar decay, he said, which takes into account everything from the placement on the tooth to the difference between different X-rays. “We’re not just taking a snapshot of what happens today, but we’re looking at the whole history, how things change over time,” he said.

Ultimately, Overjet’s goal is to help “bring the black-and-white world of dentistry into color,” Balaban said. “We want the computer to help them see.”