Esthetic dental perception comparisons between 2D- and 3D-simulated dental discrepancies

Triple digital guides for implant-supported restorations with alveoloplasty procedure in the esthetic zone

OBJECTIVE

The principal aim of this report is to address the challenge of integrating prosthetic crowns with natural dentition in the esthetic zone. It highlights the utilization of a prosthetically driven treatment plan, designed to ensure predictable esthetic outcomes.

CLINICAL CONSIDERATIONS

This report details a technique that utilizes three digital guides, all derived from a 3-dimensional digital smile design. The integration of a restoration guide, an implant drilling guide, and an alveoloplasty guide is described. These tools collectively facilitate the precise execution of both surgical and prosthetic procedures, enhancing treatment accuracy and esthetic integration.

CONCLUSIONS

This technique considers the esthetic prosthetic crowns, implant positions, and alveoloplasty collectively. It enhances the predictability of esthetic outcomes in oral implantology and potentially provides an integrated prosthetically driven workflow in cosmetic dental treatments.

CLINICAL SIGNIFICANCE

The application of multiple digital guides derived from the same prosthetically driven treatment significantly enhances the predictability of esthetic outcomes in oral implantology.

Clinical use of digital applications for diagnostic and treatment planning in prosthodontics: A scoping review

AIM

This scoping review aimed to compile and evaluate clinical trials investigating digital applications in prosthetic diagnostics and treatment planning by assessing their clinical relevance and future potential.

METHODS

Following the PCC-framework for scoping reviews and combining the source of analysis (Population/P: "prosthodontics"), the technique of interest (Concept/C: "digital application") and the field of interest (Context/C: "diagnostics"), a three-pronged search strategy was applied in the database PubMed and Web of Science. Clinical trials (≥10 study participants, English/German) were considered until 2023-03-09. Reporting adhered to the PRISMA-ScR statement.

RESULTS

The search identified 520 titles, of which 18 full-texts met the inclusion criteria for data extraction. The trials involved a total of 14,457 study participants and were mapped for prosthetic subdisciplines: fixed (n = 9; 50%) and removable (n = 4; 22%) prosthodontics, reconstructive dentistry in general (n = 3; 17%), and temporo-mandibular joint disorders (n = 2; 11%). Data merging of medical format files, as DICOM+STL, was the dominant digital application (n = 7; 39%); and virtual treatment simulation using digital smile design or digital wax-up represented the most frequent prosthetic diagnostics (n = 6; 33%).

CONCLUSION

This scoping review identified a relatively low number of clinical trials. The future potential of digital diagnostics appears to be mostly related to the subdiscipline of fixed prosthodontics, especially regarding virtual treatment simulation for communication with the patient and among dental professionals. Artificial intelligence emerged as a key technology in many of the identified studies. Further research in this area is needed to explore the capabilities of digital technologies in prosthetic diagnostics and treatment planning.

Smartphone applications for facial scanning: A technical and scoping review

INTRODUCTION

Facial scanning through smartphone scanning applications (SSA) is increasingly being used for medical applications as cost-effective, chairside method. However, clinical validation is lacking. This review aims to address: (1) Which SSA could perform facial scanning? (2) Which SSA can be clinically used? (3) Which SSA have been reported and scientifically validated for medical applications?

METHODS

Technical search for SSA designed for face or object scanning was conducted on Google, Apple App Store, and Google Play Store from August 2022 to December 2023. Literature search was performed on PubMed, Cochrane, EMBASE, MEDLINE, Scopus, IEEE Xplore, ACM Digital Library, Clinicaltrials.gov, ICTRP (WHO) and preprints up to 2023. Eligibility criteria included English-written scientific articles incorporating at least one SSA for clinical purposes. SSA selection and data extraction were executed by one reviewer, validated by second, with third reviewer being consulted for discordances.

RESULTS

Sixty-three applications designed for three-dimensional object scanning were retrieved, with 52 currently offering facial scanning capabilities. Fifty-six scientific articles, comprising two case reports, 16 proof-of-concepts and 38 experimental studies were analysed. Thirteen applications (123D Catch, 3D Creator, Bellus 3D Dental Pro, Bellus 3D Face app, Bellus 3D Face Maker, Capture, Heges, Metascan, Polycam, Scandy Pro, Scaniverse, Tap tap tap and Trnio) were reported in literature for digital workflow integration, comparison or proof-of-concept studies.

CONCLUSION

Fifty-two SSA can perform facial scanning currently and can be used clinically, offering cost-effectiveness, portability and user-friendliness. Although clinical validation is crucial, only 13 SSA were scientifically validated, underlying awareness of potential pitfalls and limitations.

Influence of facial width on the perception of lip protrusion and its differences between profile and 3-dimensional video clip

INTRODUCTION

This study evaluated the influence of facial width on the perception of lip protrusion and investigated the concordance between 2-dimensional (2D) profile images and 3-dimensional (3D) video clips in assessing lip protrusion.

METHODS

An Asian female standard head model was created using 3D modeling software. Eight head models were constructed by modifying the standard head model in terms of facial width (broad, neutral, and slim) and lip protrusion (retrusive, straight, and protrusive). Overall, 97 Asian raters rated the lip protrusion from the 2D profiles and 3D rotation video clips of the 9 models.

RESULTS

No significant differences were found in the perception of lip protrusion in terms of sex, age, or occupation. Compared with the 2D profiles, the 3D video clips were rated as more protrusive in 8 of the 9 head models, with the retrusive broad, retrusive neutral, straight broad, and straight slim faces showing statistical significance (P <0.01). The rating is significantly higher in slim faces than in broad faces across the 3 groups of 2D profiles (P <0.01). For 3D video clips, the rating was higher in slim faces than in broad faces in all 3 groups, whereas differences were significant in the straight and protrusive groups only (P <0.01).

CONCLUSIONS

In this study, 3D video clips were more sensitive to the perception of lip protrusion than were 2D profiles to some extent. The lips were rated relatively more protrusive in a slim face than in a broad face. Therefore, the relationship between facial width and lip protrusion should be considered in orthodontic treatment goals and treatment plans.

The influence of different tooth proportions obtained using digital smile design on the perception of smile esthetics

OBJECTIVE

The aim of this study is to examine the effect of designs using different esthetic dental proportions made with a digital smile design program on the esthetic perception of individuals of different ages, genders and educational statuses.

MATERIALS AND METHODS

Different smile designs were made on facial photos taken of a female and male model using a smile design program. Four different dental proportions (golden proportion [GPR], golden percentage [GPE]), Preston proportion [P] and recurring esthetic dental proportion [RED]) and two different tooth shapes (oval and square) were used. Images with 16 different smile designs were presented to 4th and 5th-year students of a faculty of dentistry, dentists, specialist dentists and laypersons for scoring.

RESULTS

The gender of the participants did not affect the scores given (p > 0.05), and participants over the age of 30 and lay people had higher scores (p < 0.05). The GPR design was scored lower than RED when all designs were subdivided by tooth shape and gender (p < 0.001).

CONCLUSIONS

The esthetic perceptions of people of different ages and dentistry education levels may differ from each other. Using the GPR when designing a digital smile may not be suitable for both genders.

CLINICAL SIGNIFICANCE

If esthetic dental proportions are to be utilized when designing a smile, it may be more appropriate to use the P and RED proportions instead of the GPR. In addition, if the patients whose smiles will be designed are young and have received dental education, it should be considered that their esthetic expectations may be high. Trial registration ClinicalTrials.gov Identifier: NCT0567043.

Perceptual difference of smile aesthetics between 2-dimensional photographs and 3-dimensional dentofacial images: a cross-sectional study

BACKGROUND

The aim of this study was to compare the perceptual difference of smile aesthetics between 2D photographs and 3D dentofacial images as perceived by orthodontists and graduate students.

METHODS

Forty-eight subjects finished orthodontic treatment were recruited with 2D photographs of frontal, oblique and lateral views as well as 3D dentofacial images. Twelve senior orthodontists and 13 postgraduate students were asked to rate the 2D and 3D smile simulations based on visual analog scale (VAS) and to vote for smile features that affect the attractiveness of smile. At the end, they completed a questionnaire about their views on different smile simulations. Wilcoxon signed-rank, Bland-Altman analysis, and multiple linear regression were used to compare the ratings and votes of smile perception between raters and between records.

RESULTS

Orthodontists and postgraduate students rated smile consistently with 2D photographs, while orthodontists tended to give a higher rate for unattractive smiles and a lower rate for attractive smiles with 3D dentofacial images. The 3D dentofacial images were rated significantly lower than 2D photographs and the voting of most of the smile features showed significant negative main effect on VAS scores, while the effect of demographic characteristics of raters, voting on visible width of upper dentition and buccal corridor was not significant. In addition, a significant negative main effect of commissure and facial profile was found on the rating discrepancy between 2D and 3D images.

CONCLUSIONS

Senior orthodontists tend to perceived 3D images more conservatively in smile evaluation. 3D dentofacial images were rated lower than 2D photographs and most of the smile features affect the aesthetic perception of smile. The perceptual difference of commissure and facial profile contributed to the lower ratings in 3D dentofacial images.

Effects of Artificial Extraoral Markers on Accuracy of Three-Dimensional Dentofacial Image Integration: Smartphone Face Scan versus Stereophotogrammetry

Recently, three-dimensional (3D) facial scanning has been gaining popularity in personalized dentistry. Integration of the digital dental model into the 3D facial image allows for a treatment plan to be made in accordance with the patients’ individual needs. The aim of this study was to evaluate the effects of extraoral markers on the accuracy of digital dentofacial integrations. Facial models were generated using smartphone and stereophotogrammetry. Dental models were generated with and without extraoral markers and were registered to the facial models by matching the teeth or markers (n = 10 in each condition; total = 40). Accuracy of the image integration was measured in terms of general 3D position, occlusal plane, and dental midline deviations. The Mann−Whitney U test and two-way analysis of variance were used to compare results among face-scanning systems and matching methods (α = 0.05). As result, the accuracy of dentofacial registration was significantly affected by the use of artificial markers and different face-scanning systems (p < 0.001). The deviations were smallest in stereophotogrammetry with the marker-based matching and highest in smartphone face scans with the tooth-based matching. In comparison between the two face-scanning systems, the stereophotogrammetry generally produced smaller discrepancies than smartphones.

A proportional appraisal of smile perception by laypersons, dental professionals, and a smile designing software: An in vivo study

Aim

To equivalence the perception of smile among laypersons, dental professionals and a commercially available popular smile designing software.

Settings and Design

In vivo - comparative study.

Materials and Methods

A total of 72 participants within age range of 18-30 years were randomly selected with a natural permanent dentition. All the subjects underwent extra oral and intra oral photographic evaluation as per the American Academy of Cosmetic Dentistry (AACD) guidelines. A total of 11 evaluators were selected for the study and were divided into four groups. The evaluation procedure comprised of assessment of patients' natural smile by laypersons, dental professionals and a smile designing software. A questionnaire was prepared for recording the responses which included a five-point Likert scale.

Statistical Analysis Used

Data was statistically analysed using SPSS version 23. Frequencies and chi square test were done for intergroup comparison.

Results

There was a statistically significant difference present in comparison across P < 0.05 all the groups.

Conclusions

There was significant difference in the perception of smile among evaluators and a smile designing software. Smile designing software prefers to modify the smile as per in built criteria and is more inclined towards creating an ideal smile.

Self-perception and self-representation preference between 2-dimensional and 3-dimensional facial reconstructions among dentists, dental students, and laypersons

STATEMENT OF PROBLEM

Computer-aided design (CAD) software can merge the intraoral digital scan with patient photographs or 3-dimensional (3D) facial reconstructions for treatment planning purposes. However, whether an individual perceives a 3D facial reconstruction as a better self-representation compared with a 2-dimensional (2D) photograph is unclear.

PURPOSE

The purpose of this observational study was to compare self-perception ratings and self-representation preference of the 2D and 3D facial reconstructions among laypersons, dental students, and dentists.

MATERIAL AND METHODS

Three populations participated in the study: laypersons, dental students, and dentists (n=20, N=60). Facial and intraoral features were digitized by using facial and intraoral scanners, and a complete-face smile photograph was obtained. Two simulations were performed for each participant: 2D (2D group) and 3D (3D group) reconstructions. In the 2D group, a maxillary digital veneer waxing from the left to the right second premolars was produced without altering the shape, position, or length of the involved teeth. A software program (Dental Systems; 3Shape A/S) was used to merge the maxillary digital waxing with the full-face smile photograph. One image was obtained for each participant. In the 3D group, a dental software program (Matera 2.4; Exocad GmbH) was used to merge the intraoral and facial scans. Subsequently, 1 video of a 180-degree rotation of each 3D superimposition was obtained. Participants evaluated both superimpositions on a scale from 1 (least esthetically pleasing) to 6 (most esthetically pleasing). Finally, participants were asked which superimposition they preferred for a potential treatment outcome representation.

RESULTS

All the ratings were esthetically pleasing (median group rating 5 or 6). When analyzed solely for differences across occupation groups, ratings for the 2D representation varied significantly across populations (Kruskal-Wallis chi-squared=13.241, df=2, P=.001), but the ratings for the 3D representation did not exhibit statistically significant differences (Kruskal-Wallis chi-squared=4.3756, df=2, P=.112). Ordinal logistic regression revealed no significant main effects but a significant effect of the population×image-type interaction on the esthetic rating. All participants felt well-represented in both the 2D and 3D representations. Also, 40% of dentists, 55% of dental students, and 50% of laypersons preferred the 3D reconstructions. Sex and occupation in general had no effect on the ratings. However, students tended to give higher ratings to the 3D representations of themselves.

CONCLUSIONS

There is no evidence based on the current study that 2D and 3D representations were perceived differently, but representation preferences may depend on a person's occupation. When individuals rated 3D visualization higher than 2D visualization, they strongly preferred the 3D visualization for representing the treatment outcome.

2D and 3D patient's representation of simulated restorative esthetic outcomes using different computer-aided design software programs

OBJECTIVE

To review the techniques and available 2D and 3D computer-aided design (CAD) software programs to perform a diagnostic waxing for restorative procedures when cone beam computed tomography is not indicated.

OVERVIEW

An electronic review was performed in Medline, Embase, and Scopus search engines. A manual search was also conducted. The articles evaluating methods to obtain a 2D or 3D patient's representation for restorative dental procedures were included. A total of 33 articles were included for full text review. CAD programs provide the capability to integrate facial features from 2D photographs or 3D facial scans and facilitate facially driven digital diagnostic waxing procedures. Diagnostic and design tools varied among the programs, and multiple technique descriptions were found. However, the literature evaluating the accuracy of virtual patients and the perception variations between the 2D and 3D dimensional representations is limited.

CONCLUSIONS

The integration of digital technologies into treatment planning procedures introduce variation into the conventional interfaces; however, the concepts remain the same. Further studies are needed to evaluate the accuracy of the virtual representations and the influence of the type of dimensional representation on the esthetic perceptions among dental professionals.

CLINICAL SIGNIFICANCE

The 2D and 3D CAD software programs facilitate the integration of facial features into digital diagnostic waxing procedures; however, the esthetic perception of the patient's virtual representation might vary among the different systems.

Rehabilitating simulated worn dentition by using a complete digital workflow and five anatomic guidelines

This report describes the rehabilitation of worn dentition by using a complete digital workflow on a nonhinged simulated patient. A dentiform was used to represent an individual with loss of occlusal vertical dimension. Interim restorations were designed following the simulated patient's midline, interpupillary line, and ala-tragus line and a defined central incisal edge position, posterior maxillary teeth central groove, and buccal cusp position of posterior maxillary teeth. The definitive restorations were then designed and fabricated by following the contour of the interim restorations.

Layperson and Dental Professional Perception When Evaluating Their Own Virtually 2D or 3D Simulated Esthetic Discrepancies

PURPOSE

To analyze the perceptions of laypersons, dental students, and dentists regarding disparities of the maxillary dental midline and the occlusal plane (OP) when analyzing their own 2D or 3D clinical simulation.

MATERIAL AND METHODS

20 participants per group volunteered (N = 60). Intraoral and facial scans, and a photograph were obtained from each participant. Two simulation groups were created: 2D and 3D groups, which were subdivided into two subgroups. In the first subgroup, the OP was modified by 1-degree increments without changing the maxillary midline. In the second subgroup, the OP was modified by the same increments, but the maxillary midline was altered to match the OP inclination. Participants were asked to rate the simulations on a 1-to-6 scale and a question survey. Ordinal logistic regression (OR) was used to analyze the ratings.

RESULTS

Tilt of the OP had the strongest negative effect on the ratings which was further amplified by the dental midline inclination (OR = 0.122). Midline modification alone did not affect the ratings (OR = 0.744). 3D simulations had a stronger positive effect on the ratings compared to 2D simulations. For dental students, the positive rating effect of 3D simulations was similar to dentists. For laypersons, the positive rating effect of 3D simulations compared to the 2D simulations decreased relative to dentists. The survey revealed that 45% of the dentists, 80% of the students, and 50% of the laypersons preferred the 3D simulation.

CONCLUSIONS

The type of dimensional representation affected the esthetic perception of all participants. 3D simulations obtained higher esthetic ratings for the same esthetic discrepancy than 2D simulations. However, all participants' ratings decreased with increased tilt of the OP and were further decreased with the inclination of the dental midline.