Digital Smile Design- An Overview of 3D Digital Workflow
Correspondence Address :
Pooja Mohan Chitlange,
Intern, Department of Public Health Dentistry, Sharad Pawar Dental College and Hospital, Datta Meghe Institute of Medical Sciences (Deemed to be University), Sawangi (Meghe), Wardha-442001, Maharashtra, India.
E-mail: poojachitlange1999@gmail.com
Smile designing is a branch of cosmetic dental procedure that corrects imperfections of the teeth and restores dental health and appearance of the person. Today Digital Smile Design (DSD) is changing the future of dental practice worldwide. It’s a unique approach to modern dentistry is revolutionising smile designing clinics worldwide. DSD is a software which used worldwide, is based on specific photographs and software analysis. DSD is a tool (software) that helps in easy communication and discussion between all the smile designers, dental laboratory technician as well as with patients. DSD especially can be used in a multidisciplinary approach and hence not only used in prosthetic rehabilitation but also used in other branches of dentistry like Orthodontic, Periodontics, etc., The concept of smile designing is not new. The need of aesthetic can be traced from the earliest civilisations of both the Phoenicians (about 800 BC) and Etruscians (about 900 BC). They used to carve animal tusks to simulate the shape, form and hue of natural teeth. Pierre Fauchard (1678-1761) from of France, together with several colleagues modernised and promoted dentistry and also started aesthetic practices. There are many parameters such as dentofacial parameter, gingival parameter, ease of use, documentation ability, cost, time required, systematic digital workflow and organisation, and compatibility of the program with Computer-aided design/Computer-aided Manufacturing (CAD/CAM) or other parameters that may affect the user’s decision. DSD helps both clinician and patient to improve treatment planning and stimulate the final results of the treatment. There are many software available, and the clinicians can use any of the software according to their needs. Some software can be used easily as a mobile app. This article reviews the basic principles of smile design, various parameters of smile design, comparison of various software, uses, advantages and limitations of DSD.
Aesthetic dentistry, Computer-aided design and computer-aided manufacturing, Cosmetic dentistry, Intraoral scanner, Smile
Cosmetic dentistry has the ability to not only change but also enhance once appearance. Smile designing is a branch of cosmetic dentistry that corrects disturbances of the teeth and restores dental problems and aesthetics of the person. Having a smile you love increases your confidence as well as your self-esteem. Smile is the first to be noticed by someone when they look at you. Now, it is possible to achieve your dream smile with smile designing. Today DSD is changing the future of dental practice worldwide. It’s a unique approach to modern dentistry is revolutionising smile designing clinics worldwide. Teeth have always been considered the most important factor for beauty (smile) (1). The main objective of a smile designing is to fulfil patient’s requirements and the results of the procedure should enhance patient’s facial aesthetics and smile. Smile designing is an irreversible procedure, so it is difficult to convince and educate through conventional smile design technique but with DSD it is very easy to motivate and educate patient by developing and showing the smile digitally and it helps them to visualise it prior to the treatment by creating and presenting a virtual simulation of their new smile design.
The DSD is a software which used worldwide, is based on particular photographs and software analysis (2),(3). DSD is a tool (software) that helps in easy communication and discussion between all the smile designers, laboratory technician as well as with patients. DSD especially is a multidisciplinary approach and hence, it is not only used in prosthetic rehabilitation but also used in other branches of dentistry like Orthodontic, Periodontics etc., (4). DSD workflow needs an intraoral scanner and software programs, photographs and videos. Intraoral scanners are dynamic instruments that allow for instant evaluation of impression quality and the ability to submit models to the laboratory via e-mail, minimising money and time (1).
Background
The concept of designing a smile is evolving continuously. The demand for aesthetics can be traced back to the Phoenicians (around 800 BC) and Etruscians (around 900 BC). They used to carve animal tusks to mimic the form, shape and colour of real teeth (2). Pierre Fauchard (1678-1761) from France, together with several colleagues modernised and promoted dentistry and also started aesthetic practices (3). The concept of smile designing developed rapidly during 18th century. During 18th century the oral health was affected due to the wide spread of caries, because of high intake of sweets, poisoning due to heavy metals and some systemic diseases. Therefore, over the time, the demand for aesthetics increased more among the high socio-economic groups before spreading among the population. Modern dentistry attempted to satisfy the aesthetic and functional needs by developing a variety of novel treatment alternatives (4). In recent years, smile design has advanced from traditional (manual) smile design to DSD, which has now improved from 2 Dimensional (2D) to 3 Dimensional (3D). Previously, manual drawings on printed photographs of the patient were used for the demonstration of the end results of therapy; however, this has since been replaced with absolute automated drawing using DSD software on a computer. This is simple to operate, edit and explain to patients (5). In the year 2017, Christian Coachman has proposed the evolution of Digital Smile Design Software (DSDS) as six generations described in (Table/Fig 1) (6).
Components of Smile Aesthetics
The components of smile aesthetics are divided into four main components which are facial aesthetics, gingival aesthetics, macro-aesthetics and micro-aesthetics (7). The components of smile aesthetics contain various parameters of analysis which are listed in (Table/Fig 2).
Digital Smile Designing Procedure
The cosmetic aspects in different DSD software vary, but the core method of constructing a smile stays the similar. All of the programmes allow you to build your own smile by drawing reference lines and structures on intraoral and extraoral images. The front image of the face is created using reference lines of facial analysis. The horizontal guiding lines are intercommissural lines and interpupillary lines which offer a perfect balance on the horizontal parts of an aesthetically attractive face, while the vertical guiding lines are the glabella, nose, chin, dental midline and mandible (8),(9). DSD allows a relative analysis of the teeth and face after determining horizontal and vertical proportion. Dentogingival analysis is performed after face analysis. The gingiva shown is determined by the measurement of height of the top lip at rest and during smiling. The smile curve is obtained by connecting the curvature of the incisal margins of the upper front teeth. The proportions of the lower lip and the anterior-posterior curve of the teeth establish the dental contour. This face image’s intraoral view is then cropped. On the teeth, three reference lines are drawn: a horizontal straight line from tip of one canine to the tip of another canine, a vertical line crossing the midline (passing from the interdental papillae) and a horizontal line on the incisal margins of central incisors. This helps to reproduce the cross, i.e., the reference facial midline on the face and interpupillary line, onto the intraoral view. A few other lines are drawn for a full dental study, such as the connecting lines of the gingival and incisal battlements and the gingival zenith (5).
Some theories are used for the selection of ideal dimensions of teeth for ideal size of dental length to width ratio, Golden proportion, Pound’s theory, Visagism, Dentogenic theory or recurring aesthetic dental proportion (10),(11),(12),(13),(14),(15). After all of the preliminary work has been completed a digital ruler is used to make the necessary modifications. The alterations can be customised to the patient’s aesthetic preferences and unique demands (16). A fresh smile is displayed to a patient once all of the modifications have been completed. This digital smile may be used to prepare a final model that can be visually assessed in the patient’s oral cavity. The model not only permits visualisation of gingival architecture, lips and facial shape, but also speech during the try-in phase before any permanent alterations occur (17). The complete workflow of DSD is shown in (Table/Fig 3) (5),(18).
Workflow of Digital Smile Design (DSD)
The following are the proportions used in smile designing;
Golden proportion: The golden proportion was initially stated by Lombardi in dentistry and Levin subsequently developed it. When a line is divided into two sections in the golden proportion, the ratio of the small segment to the large segment is equal to the ratio of large section to overall line. The golden proportion or divine proportion, ratio of following terms is about 1:1.618 (19).
Facial proportion: The rule of thirds separates the face vertically into about three equal portions in facial proportion. The lower 3rd of the face is then divided into three parts, with the incisal plane ideally situated at the intersection of the top and middle third (19).
Dental proportion: The height of the ideal central incisor should be one-sixteenth of the height of the face from the ideal hairline to the chin and the width should be one-sixteenth of the interzygomatic width (19).
Golden percentage: Snow analysed the individual apparent tooth width as a proportion of the overall apparent width of the six anterior teeth bilaterally. In order to generate an aesthetically attractive grin, he established the golden percentage, which states that the proportionate width of individual tooth should be 25% central incisor, 15% lateral incisor and 10% canine of the overall width of the anterior section (19).
There are many DSD software developed by different companies. The clinician can use any of the programmes according to the needs. The (Table/Fig 4) shows the list of the DSD software available.
Many aspects, including dentofacial parameter, gingival parameter, documentation capability, cost, ease of use, systematic digital workflow and organisation, time required and application compatibility with
CAD/CAM, may impact the user’s choice. Many aesthetic criteria, including the facial midline, dentofacial midline, gingival height and contour, facial profile, height and smile curve, as well as intra and interdental proportions, influence smile evaluation and design (20),(21),(22).
In year 2017, Omar D and Duarte C, conducted a study comparing eight DSD softwares (Photoshop CS6, Keynote, Planmeca Romexis Smile Design, Cerec SW 4.2, Aesthetic Digital Smile Design (ÀDSD), Smile Designer Pro, DSD App and VisagiSMile) (22). With over 25 parameters but the scoring was done based on 20 parameters. The (Table/Fig 5) shows the 12 face analysis parameters, three dentogingival analysis parameters, five parameters of dental analysis, and five additional parameters that were chosen from the examined literature (10),(11),(12),(23),(24),(25),(26),(27),(28),(29),(30). Despite the fact that the application was not designed particularly for dental use, it was found that keynote and photoshop CS6 provide a more comprehensive smile design than other professional DSD programmes (23).
According to Omar D and Duarte C, out of 20, photoshop scored 20, followed by keynote which scored 19 out of 20 (22). Photoshop has capability to fulfil all the parameters of the facial, dentogingival, dental analysis (31),(32),(33). Similar to photoshop, keynote can analyse every parameter but was not able to change and create detailed ideal changes on the tooth structure (34),(35). Both keynote and photoshop are photo editing software hence, cannot be specific for dental use. It cannot be operated by mobile phone and cannot be used with CAD/CAM. The software is not developed for patient documentation and dental use therefore, required special training to operate this software. Similarly, ADSD program scored 18 out of 20, but it contains limited facial analysis parameters (36),(37). The software is specifically developed for DSD and the workflow has been designed for dental use. This software is also not used with CAD/CAM. It requires fewer operative skills to operate software effectively. However, the functionalities are confined to those currently present in the software (32).
Planmeca Romexis Smile Design is a DSD software that may be used to simulate smiles, plan treatments and communicate effectively. It is compatible with both Mac and Windows. It doesn’t need any additional software to work. It’s quick and easy to use. Designing a smile with a 2D face shot and accurate teeth selection takes only a few minutes. The programme enables the operator to carefully alter the location, shape and size of each tooth in order to obtain perfect proportion and aesthetics (33),(35).
Cerec SW 4.2, scored 13 out of 20 (38),(39). This software is not efficient as above-mentioned software in facial and dentogingival parameter analysis. There are very few frontal facial parameters and facial profile parameters incorporated in this software. This software can be used with CAD/CAM but cannot be operated as mobile app. Additionally, DSD App, SDP and VisagiSMile programs had similar scores, 10 out of 20 (34),(40),(41),(42). The most significant disadvantages of these programmes were discovered in the analysis of facial component, which is typically employed for picture calibration in these systems. These programmes did not contain frontal face parameters or facial profile parameters. Some of these programmes however, unable to change delicate natural aspects, which can result in a less convincing digital replica of the smile. Later in 2017, the DSD app intended to encompass every area of frontal and facial profile analysis, as well as an orofacial surgical simulation extension (22),(42).
Photoshop, keynote and ADSD has a greater number of aesthetic analysis parameters. Other DSD softwares has a smaller number of aesthetic analysis parameters but incorporated comprehensive dentogingival and dental aesthetic functions. The PRSD, Cerec SW 4.2 and DSD App all supported 3D processing moreover, Cerec SW 4.2 and PRSD can be used in conjunction with CAD/CAM. Both the smile designer pro and DSD app can be operated as mobile phone software (22),(23).
In the year 2017, Santos FR et al., performed a periodontal surgery for gummy smile with the help of DSD. The results of the surgery were excellent and patient was happy with the end results. He concluded that by the help of DSD it is very easy to demonstrate the end results of the treatment to the patients (43). Garcia PP et al., published a study report of a maxillary anterior rehabilitation using the DSD system and a direct model technique in 2018. He found that the use of DSD in association with mock-up for diagnostic and treatment planning yielded good results in the cosmetic rehabilitation of the front teeth (44). Stanley M et al., conducted a case study in 2018. In this scenario, DSD software and CAD/CAM (monolithic lithium disilicate) ceramic veneers and crowns, were used to alleviate vertical dimension loss, aesthetics, and temporomandibular joint diseases (following a minimal tooth preparation technique) (14).
Advantages of Digital Smile Design (DSD)
• DSD assists patients in visualising the predicted outcomes prior to beginning treatment. This enhances the treatment’s predictability (45).
• Operator can motivate and educate the patient by showing the final outcome digitally before doing any irreversible procedure this can also serve in crucial medicolegal purposes (5).
• Clinicians and patients can both digitally visualise and analyse gingival, dental and facial characteristics that will decide the final smile and facial aesthetics (46).
• DSD contributes to the personalisation of smile design by exceeding patient’s involvement in their own smile designing, results in a more cosmetically motivated, emotive and confident smile (46).
• Before the treatment begins, comparison between before and after treatment images using a digital scale, horizontal and vertical reference lines can be done (46).
• DSD not only helps in better communication between patients and clinician but also helps in better communication between other team members, lab technician, etc.,
Limitation of DSD
• The evaluation and further planning depend only on photos and videos, any variation in documentation may result in distortion of reference image and results in improper diagnosis and treatment planning.
• The treatment with DSD is economically expensive as for complete 3D digital work updated 3D software, CAD/CAM software, intraoral scanner and 3D printer are necessary (5).
• Some software requires specific training to operate software which makes it more costly and time consuming. Although, the complete procedure is time consuming, the results of the software are very good. As the technology is developing the limitations of the system can be overcome.
From the above discussion, it can be concluded that as in this new era cosmetics and aesthetics are of more concern, everyone loves to have perfect smile and aesthetics. DSD has made the smile designing very easy. There are many advantages of DSD with limitations. DSD especially is a multidisciplinary 3D approach and can be used in various different branches of dentistry. There are many softwares available. clinician can use any of the software according to their needs. Some softwares can also be used easily as a mobile app. Thus, being user friendly and convenient to use and helping both the clinician and the patient to improve the treatment planning and stimulate the final results.
DOI: 10.7860/JCDR/2023/61467.17386
Date of Submission: Nov 14, 2022
Date of Peer Review: Dec 05, 2022
Date of Acceptance: Dec 12, 2022
Date of Publishing: Jan 01, 2023
AUTHOR DECLARATION:
• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? Yes
• Was informed consent obtained from the subjects involved in the study? NA
• For any images presented appropriate consent has been obtained from the subjects. NA
PLAGIARISM CHECKING METHODS:
• Plagiarism X-checker: Nov 22, 2022
• Manual Googling: Nov 26, 2022
• iThenticate Software: Dec 07, 2022 (9%)
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