Interview: What is Deep CBCT analysis and what does it mean for the orthodontist?

Russian start-up 3D Smile was founded in response to a lack of software applications for aligner treatment

Marina Domracheva, the founder and CEO, personally supervised all steps of aligner production, from 3-D printing and finishing of printed models to contracting dental clinics. This allowed her to quickly understand all the barriers and demands of the dental laboratory, specifically regarding the digital workflow for aligner treatment and made it possible for the company to grow into a developer of specialised software for aligner treatment. At the 2019 Annual Session of the American Association of Orthodontists (AAO) in Los Angeles in the US, Theodore Aptekarev, the company’s chief technology officer, told Dental Tribune International about 3D Smile and its deep CBCT analysis software.

Mr Aptekarev, what is 3D Smile and Deep CBCT analysis?

We are a software developer and aligner manufacturer. The company was founded in 2014 in Moscow in Russia, and we are now entering the US market. It is our first time at the AAO annual session.

As an aligner company, we developed a tool that differentiates us from any aligner company in the world. We call it “Deep CBCT analysis”. It is a software tool that allows dentists and technicians to do treatment planning based on the bone and roots and enables them to avoid anatomically impossible tooth movement at the treatment planning stage.

We did an analysis of 1,700 patients with and without Deep CBCT analysis, and the results were that the use of Deep CBCT analysis reduces the probability of a mid-course correction or early refinement by up to two times. Statistically, it potentially shortens the treatment time by up to 30%.

Does 3D Smile operate exclusively in Russia at the moment and is your presence at the AAO annual session a step towards expansion to the US?

At the moment, we sell our brand in Russia, eastern Europe, eastern Scandinavia and the Baltic countries. We are an ISO medical device-certified manufacturer and are working on addressing all the regulatory barriers to start selling in the US and are waiting for Food and Drug Administration approval to sell our own aligners here.

For what cases is Deep CBCT analysis a good tool for an orthodontist?

For dentists treating patients with bite protrusion, larger arch expansions and crowding of over 3 mm.

If we consider bite protrusion, having information at the treatment planning stage about how the roots will move and what their shape is, gives the dentist essential information, such as a possible root collision, and allows him or her to reconsider his or her approach, to rethink the whole treatment. If he or she knows the possible obstacles, he or she can offer a shorter treatment, without the root collision, that is more predictable and thus more effective.

Mesial root angulation is an anatomically impossible type of movement which cannot be guessed even from the root perspective. The software offers two treatment plans, one with mesial root angulation, the other with crown angulation. We could have a case where from the crown perspective the plans look more or less the same, but from the root perspective show a high mesial root angulation. If the angulation is too high, it may be impossible to move the tooth. At some point, the tray will not fit, the patient will not be happy etc. Therefore, knowing this beforehand allows the dentist to change his or her approach, change the root angulation to crown angulation via distalisation, and get a predictable treatment plan.

Uncontrolled arch expansion can lead to a posterior open bite. If we try to move two molars, but the roots of the molars will meet the cortical plate, instead of moving, the molars will just tilt. When the teeth tilt, the cusps start contacting each other and this will result in both of the molars going into intrusion, leading to a posterior open bite, a different complication needing treatment by itself and therefore creating a new problem.

The visualisation provided to the dentist at the treatment planning stage includes a coloured distance map showing the distance from the edge of the root to the edge of the bone, allowing the dentist to see if anything dangerous could arise. It shows all the things the dentist should not do or that can go wrong when planning the treatment, for example, the possibility of seeing how the root angulation should not be done.

Our Deep CBCT analysis produces a web-based 3-D planner (no need to install anything), yielding high-resolution and fully animated 3-D models. An international patent for it is pending approval.

Most dentists working with aligners use 3-D planning, so what makes your software stand out?

If you are a dentist who understands radiography and how to use the modern complex radiographic software that comes with CBCT machines, then you can take the time to look at the radiographic images and build your own 3-D reconstruction from them, to understand the initial condition. I don’t think that all dentists are able to use the sometimes impossible interface or software of a radiographic machine or always have the expertise to be able to read through all the 3-D digital data; therefore, they need assistance to help them interpret this data.

3D Smile takes the plurality of digital data and sorts it out for them. We just take what is needed for this particular application, for orthodontists who do clear aligners; we could say we take oranges and make orange juice for them. We do data fusion, fuse high-resolution 3-D models of the crown that come from an intraoral scan with the root models that we obtain from our Deep CBCT analysis.

It’s apparent that you are very proud of and passionate about this technology.

Indeed I am. We have had unbelievable results. We launched the Deep CBCT analysis technology at the International Dental Show in 2017, and a good example for you to understand the progress we’ve made since then is to tell you that at that time we needed 2.5 hours of computing time to process one case. Now the turnaround time for one of our clients in China, for example, is 19 minutes. That includes taking all the data from China, transferring it to our data centre, doing all the computations and transferring the results back through the Great Firewall of China.