How Would You Assess the State of Digital Smile Design?

Christian Coachman, DDS, CDT; Galip Gurel, DDS; Diogo Alves, DDS and Ralph Georg, MS

Dr. Coachman

Modern restorative dentistry is comprehensive and interdisciplinary. Interdisciplinary treatment planning is facially driven and starts with smile design. Consequently, improving the process of designing adequate smiles has become paramount. Until recently, tools and systems to design smiles were quite limited, and facial harmony was difficult to achieve. Smile rehabilitations required many adjustments, involved a considerable amount of "back and forth," and final outcomes were not always ideal. This was due in part to inadequate dentist-technician communication protocols, lack of orofacial esthetic knowledge, and restrictive tools and workflows.

My personal journey as a smile designer has gone through several stages. Initially, tools were very limited, often even lacking facial images. We sometimes drew over smile photographs by hand. Without reference to the face or working model, it was impossible to facially guide the diagnostic wax-up. Significant adjustments were usually needed upon intraoral try-in, as the creation of harmony between face and smile was largely a guessing game. It was as though the patient's mouth was being transformed into a "laboratory" to test initial ideas. Facebows and articulators were helpful from a functional perspective but useless for dentofacial esthetic integration. Airway was completely ignored during the diagnostic wax-up.

Next came digital 2D drawings done with Keynote or PowerPoint software over the patient's facial pictures to draft a potentially ideal smile. To transfer it to a wax-up, the clinician relied only on a visual connection between the drawings on the computer and the design/wax-up over the model. This, at least, enabled us to learn about and consider the face as an important aspect of smile design. The process evolved significantly with digital tools to make measurements over the 2D digital design and transfer these measurements with a caliper and pencil to the model as guides for the wax-up design.

The process became predictable with 3D software used to integrate the face into the design. The calibration of the intraoral STL scan file and the facial picture was a critical breakthrough that made the so-called "2D-3D connection" possible. It facilitated facial analysis and drawing of guidelines over the facial images and the ability to overlap them with the 3D model to guide the design. At this point, 3D digital diagnostic "wax-ups" were introduced, which are still used in every case.

The next advancement was a software to not only design smiles but also provide specialty treatment simulations; this finally brought the concept of interdisciplinary treatment simulations to reality. This means creating orthodontic, orthognathic, periodontic, implant, and restorative simulations guided by the initial facially driven digital smile design (DSD). This powerful visual communication tool took team communication, planning, and decision-making to the next level.

Today, dentistry is moving into a complete 3D workflow by substituting the facial 2D images with facial 3D scans. This eliminates another limitation: inappropriate photograph angles. It also facilitates an even more complete analysis of the face in every angle. Another feature under development is integration of facial and jaw movements into the full DSD process. Jaw motion tracking devices that capture mandibular movements into the 3D software and digital articulators are already available, making artificially generated jaw movements in an analog articulator obsolete. The final missing link to DSD is the movement of the face. Videos are still relied upon to evaluate facial movements and lip dynamics. It is expected that soon more affordable devices will become available to scan the face and dynamic movements in 3D as well.

Exciting developments in smile design have happened in recent years. Looking ahead, increasingly intuitive and affordable solutions should become available to allow more dentists and their patients to benefit from predictable, comprehensive, healthy, and natural-looking smile rehabilitations.

Dr. Gurel

Before discussing digital smile design (DSD), let's first talk about smile design. In today's dentistry, the whole treatment is based on achieving the final esthetic outcome of the case. This final outcome should be defined at the very beginning of the case, and the treatment planning should be based on finally achieving that design.

This initial smile design, or mock-up, whether achieved in an analog or digital manner, is the most crucial step for many different reasons. First, it will be the first "visual communication" between the dentist and patient and, therefore, should be presented as impeccably as possible. Second, it will allow the dentist and patient to "test drive" the new design in motion (live with the patient). Third, the mock-up should be realistic in order to guide the rest of the treatment planning. And, finally, it should be delivered quickly, preferably at this first esthetic consulting appointment, where the patient would be most influenced. In my daily clinical practice, I still always use the direct mock-up technique for this first design simply because I have been doing it this way for years, and, more importantly, it flows in an interactive fashion with the patient.

Dentistry entered into the digital era over the course of the past two decades, starting with data acquisition, smile design softwares (CAD), and manufacturing (CAM and 3D printing). I believe that in the very near future robotics will be completing this whole digital workflow.

Among the different digitally driven applications mentioned above, DSD had already been on stage, and there have been many different apps and softwares in the market for a number of years. Some are based on the softwares created by entrepreneurial dentists, including groups such as Digital Smile Design, SmileCloud, Ivosmile, and Rebel, and some are attached to the softwares of intraoral scanners.

DSD certainly requires a learning curve, and it will take dentists away from their comfort zone. Meanwhile, they also must still know the fundamental basics of creating a smile design. The advantage is that currently almost all the digital smile design softwares work over at least a 2D full-face photograph (if not 3D) so that the designs are done in a facially driven manner. Some programs are more user-friendly than others, and it may take time to develop skills with regard to modifying the lines and line angles, positioning the teeth, etc, on a computer.

Perhaps the last piece of the DSD puzzle yet to be developed is the automated immediate conversion of the 2D smile design into 3D. Most softwares require an intermediate step of sending this 2D data to an experienced lab to have this 3D design done, which adds extra cost and time.

Going forward, the software that is the most user-friendly with the function of automatically converting 2D designs into 3D and immediately allows dentists to 3D-print this model, and provides the opportunity to try-in the new smile design in the patient's mouth at the very first appointment will set the standard.

Dr. Alves and Mr. Georg

Simply put, digital smile design (DSD) is a technical tool used to design and modify a patient's smile digitally and help the patient visualize the smile before the treatment physically starts. With this process a digital mock-up of the new smile design is created and presented to the patient beforehand, providing visual communication and encouraging patient involvement in their own smile design. This can help ensure a predictable treatment outcome and increase case acceptance.¹

Smile design workflows, ideas, or methods have been in use for several decades. Motivational smile design is a creative way to visually explain to the patient the advantages of an esthetic treatment. It used to be that dentists and technicians drew pictures. The first software was created in the late 1980s and ran on DOS. The use of PowerPoint followed, which was an improvement. Different software solutions then emerged, continuing right up until today. All of the solutions so far, however, have the same major issue: the workflow is based on a 2D picture analysis, 2D smile simulation, and 2D plan. Technically, it is impossible to create a 3D smile design based on a 2D smile simulation having 2D outlines as templates and the corresponding 3D templates.

On the frontal smile photograph, the designer sets some visual references called a "smile frame" to define the "smile curve" and the height and width of the teeth templates. 2D outlines visualize the position and the size of the smile design. The designer modifies the height and width of these outlines to simulate the outcome of the esthetic treatment. The limitations of the DSD concept lie in the fact that a 2D reference cannot visualize and represent a 3D object in space (tooth template) considering all the factors that play important roles in esthetic planning.

From a dental planning point of view, the 2D digital smile design has no clinical value and cannot be used as a "plan" for the 3D design.

About the Authors

Christian Coachman, DDS, CDT
Founder and Chief
Executive Officer, DSD-Digital Smile Design; Private Practice,
São Paulo, Brazil

Galip Gurel, DDS
Visiting Professor at New York University College of Dentistry, New York, New York, and University of Marseille Faculty of Dentistry, Marseille, France; Past President, European Academy of Aesthetic Dentistry; Private Practice, Istanbul, Turkey

Diogo Alves, DDS
Clinical Content Specialist, SmileFy Academy, Miami, Florida; Post-Graduate in Implantology and Implant Prosthodontics, Federal University of Paraná, Brazil

Ralph Georg, MS
Creator and Founder,
SmileFy Academy,
Miami, Florida

Reference

1. Jafri Z, Ahmad N, Sawai M, et al. Digital smile design - An innovative tool in aesthetic dentistry. J Oral Biol Craniofac Res. 2020;10(2):194-198.