Comparison of user satisfaction and image quality of fixed and mobile camera systems for 3-dimensional image capture of edentulous patients: A pilot clinical study

Comparative evaluation of novel framework-supported 3-dimensional facial scanning using smartphone device with freehand facial scanning in patients seeking orthodontic treatment: A cross-sectional study

INTRODUCTION

Surface anthropometric assessment of soft tissues is an ideal approach for measuring 3D facial changes with smartphone/tablet-based applications revolutionizing 3D facial acquisition. However, the scans obtained are prone to distortion and have limited repeatability due to the freehand recording of the scans in continuous image capture mode, thus also reducing their reliability. The aim was to introduce the design and operation of an innovative apparatus for acquiring 3D facial scans in a standardised, repeatable, and convenient way for young children and adults.

MATERIAL AND METHODS

The apparatus presents a framework with a straight and scissor arm with the recommended dimension of 68×60×34cm with a 360-degree rotatory joint similar to wall-mounted X-ray systems used in dental offices. Facial scans of 15 patients aged between 19-25 years (mean age=23.13 years) were recorded using the two techniques (framework-supported [SF] and freehand [SWF]) Scandy Pro app in Apple iPad Pro. The scans were exported in .stl format and analysed using Meshlab and Viewbox 4 software for surface comparison, scan time, and mean absolute distance (MAD) between facial soft tissue landmarks.

RESULTS

Scans using the framework (SF) showed fewer aberrations, especially in the nasolabial and periorbital areas. Zygoma R and L (0.608±1.605 and 0.503±1.191 respectively) displayed the most difference, while Point A (0.323±1.381), Pogonion (0.364±1.344), and infraorbital region R and L (0.307±0.785 and 0.362±1.089 respectively) displayed the least. With no scan interruptions, the average scan time decreased threefold to 10.14seconds for SF compared to 27.81seconds for SWF, with 12 instances of tracking loss. Superimposition analysis of SF scans shows ICC values from 0.574 to 0.882, indicating good agreement.

CONCLUSION

The proposed framework provides a reliable, accurate, and cost-effective alternative for 3D facial imaging using smartphone devices. It demonstrates high reproducibility and significant reductions in scan time and tracking loss. This apparatus could facilitate the routine clinical use of 3D facial scanning in orthodontics, offering portable and non-invasive solutions.

Trueness and precision of a handheld, a desktop and a mobile 3D face scanning system: An in vitro study

OBJECTIVE

This in vitro study investigated the trueness and precision of three different face scanning systems: a handheld, a desktop and a mobile 3D face scanning system.

MATERIAL AND METHODS

Fourteen landmarks were placed on a mannequin head, and sixteen inter-landmark distances were measured using a digital vernier caliper, repeated 20 times over 80 days. Three 3D face scanning systems were evaluated: a handheld (Metismile; Shining 3D Tech Co., Hangzhou, China), a desktop (RAYFace v2.0; Ray Co., Ltd., Gyeonggi-do, Korea), and a mobile application (Heges, Simon Marinek) on a smart device (iPad Pro X, Apple Inc., Cupertino, CA). Sixty facial scans were analyzed using metrology software (Geomagic Control X), and inter-landmark distances were compared to anthropometric measurements. Trueness was determined by absolute linear deviation and analyzed using one-way ANOVA, with Bonferroni and Tamhane tests for significant variance. Precision was compared to anthropometric measurements and analyzed using Kruskall-Wallis test.

RESULTS

3D analysis showed that the handheld scanner had the highest trueness (0.18 ± 0.15 mm) and precision (0.22 ± 0.04 mm). The desktop scanner had a trueness of 0.35 ± 0.26 mm and precision of 0.61 ± 0.18 mm, while the mobile scan application had a trueness of 0.54 ± 0.34 mm and precision of 0.47 ± 0.12 mm. All systems showed the highest trueness for vertical measurements compared to horizontal measurements. In the lower face, the precision was higher than anthropometric measurements for all 3D face scanning systems.

CONCLUSIONS

The handheld scanner demonstrated the highest trueness and its precision surpassed anthropometric measurements. The desktop scanner outperformed the mobile scan application in trueness but not in precision.

CLINICAL SIGNIFICANCE

The handheld, the desktop and the mobile face scanning system showed clinically acceptable trueness (< 0.6 mm) and could be used for virtual facebow transfer. All 3D face scanning systems in the present study demonstrated superior precision in the lower face compared to anthropometric measurements.

Evolution of Dental Occlusion: Integrating Digital Innovations

The landscape of dental occlusion is undergoing a transformative shift with the integration of digital technologies offering accuracy, efficiency, and improved patient outcomes. This article explores the advancements in digital innovations that have reshaped occlusal analysis and management. By examining tools such as three-dimensional (3D) scanning, virtual articulators, and occlusal diagnostic software, we highlight their impact on treatment planning and clinical workflows. These technologies enable dental professionals to analyse occlusal relationships with a level of detail previously unattainable, paving the way for more accurate and individualised treatment plans. The implementation of digital approaches also enhances patient engagement, as visual data aids in understanding treatment processes. This article also reviews the available research on the reliability of these innovations, providing an evidence-based perspective on their clinical application.

Clinical evaluation of the accuracy of two face scanners with different scanning technologies

OBJECTIVES

This study compared the clinical accuracy of two different stationary face scanners, employing progressive capture and multi-view simultaneous capture scanning technologies.

METHODS

Forty dentate volunteers participated in the study. Soft tissue landmarks were marked with a pen on the participants' faces to measure the distances between them. Clinical measurements were manually obtained using a digital vernier caliper by two independent examiners. The participants were then scanned using one of two stationary face scanners: Obiscanner (Fifthingenium), which employs progressive capture technology requiring the subject's head to rotate during image acquisition, or RAYFace (RAY), which utilizes multiple cameras to simultaneously capture a complete 3D image. The scans were imported into mesh-processing software, and digital measurements were taken by the same examiners. Data analysis included pairwise comparison tests and the calculation of the intra-class correlation coefficient (ICC; α = 0.05).

RESULTS

Digital measurements were significantly longer than clinical measurements across all measured distances (p < 0.001). Comparisons between the scanners revealed that vertical measurements using RAYface exhibited greater percentage differences compared to those using Obiscanner (p < 0.05), while horizontal measurements were more variable with Obiscanner than those obtained using RAYface (p < 0.05). Intra-examiner differences were significant for both methods (p < 0.001), although inter-examiner differences were only significant for clinical measurements (p < 0.001), not for digital measurements (p > 0.05). Inter-examiner reliability for digital measurements was high (ICC≥0.99).

CONCLUSIONS

Significant differences were observed in the accuracy of the two stationary face scanners using progressive capture and multi-view simultaneous capture scanning technologies, with each device demonstrating specific strengths and limitations.

CLINICAL SIGNIFICANCE

Although face scanners offer relatively high accuracy and consistency, particularly across different acquisition technologies, careful consideration of their performance characteristics is essential for optimizing accuracy in facial measurements.

Reliability of a face scanner in measuring the vertical dimension of occlusion

OBJECTIVE

This study evaluated the reliability of a face scanner in measuring the vertical dimension of occlusion (VDO).

METHODS

Fully dentate volunteers (n = 20; mean-age = 30.0 ± 10.7 years) were recruited. Clinical facial measurements were obtained using a digital caliper and a face scanner (Obiscanner, Fifthingenium, Italy). The scans were imported into a mesh-processing software, and the distances were measured digitally. Measurements were obtained for each participant with the jaws positioned in maximal intercuspation (MI) and with increased vertical distances of 2, 4, and 6 mm. Vertical and horizontal measures were obtained using facial anatomical landmarks: Glabella (GL), Pronasale (PrN), Subnasale (SbN), inferior border of the right and left Alare, Labiale superius (Ls), right and left Cheilion (Ch), Soft Pogonion (SPg), right and left Tragus of the ear (Tr), for all selected vertical positions. Data analysis included intra-class correlation coefficient (ICC), pairwise comparison tests, Bland-Altman plots, and Passing-Bablok regression.

RESULTS

120 VDO measurements (clinical=60, digital=60) were recorded by two independent evaluators. Mean differences between digital and clinical measurements ranged from 0.054 ± 0.14 mm to 0.203 ± 0.13 mm. All parameters were strongly correlated (r > 0.93; p < 0.001). ICC estimates revealed excellent reliability, and the measuring procedure yielded the same results on repeated trials irrespective of the raters and measurement methods. Bland-Altman plots revealed a difference, between digital and clinical measurements, of 1.7 % for the vertical measurements. Regression analysis revealed no significant proportional difference between the two methods, so both can be used interchangeably.

CONCLUSIONS

The findings of this study demonstrate that VDO can be measured accurately from face scans using 3D mesh-processing software and that even small changes in the VDO could be detected using the digital methods.

CLINICAL SIGNIFICANCE

Findings provide evidence about the reliability of a digital method for jaw relation registrations and may be applied towards incorporating this method into clinical workflows for computer-aided-design/ computer-assisted-manufacturing (CAD-CAM) dentures.

Evaluation of the 3D error of 2 face-scanning systems: An in vitro analysis

STATEMENT OF PROBLEM

Facial scanning systems have been developed as auxiliary tools for diagnosis and planning in dentistry. However, little is known about the trueness of these free software programs and apps for facial scanning.

PURPOSE

The purpose of this in vitro study was to evaluate the trueness of 3D facial scanning by using Bellus3D and +ID ReCap Photo.

MATERIAL AND METHODS

A mannequin head was used as the master model. The control group was created by scanning the mannequin head with a noncontact structured blue light 3D scanner (ATOS Core). Two facial scanning methods were used for the experimental groups: a facial scanning app (FaceApp) and the Plus identity photogrammetry methodology (ReCap Photo). In both methods, image capturing was performed under the same natural lighting conditions with a smartphone (iPhone X) calibrated with an app. Trueness was assessed from the 3D measurement error, which was calculated with a 3D mesh analysis software program (GOM Inspect). Two comparison groups were created: ATOS versus Bellus3D (B3D) and ATOS versus +ID with ReCap Photo (+IDRP). The results were statistically evaluated by using the Shapiro-Wilk and paired t tests (α=.05).

RESULTS

B3D had a greater error than +IDRP in measuring the regions of the upper and lower lips, nose, and mentum (P<.01). This error was statistically higher for +IDRP (P<.01) in the right face area, but the left face area showed no statistically significant difference between the evaluated scanning methods (P=.93). The 3D global trueness of B3D was 0.34 ±0.14 mm, and that of +IDRP was 0.28 ±0.06 mm.

CONCLUSIONS

Both methods evaluated in this study provided a 3D model of the face with clinically acceptable trueness and should be reliable tools for planning esthetic restorations.

Esthetic treatment planning with digital animation of the smile dynamics: A technique to create a 4-dimensional virtual patient

A method is presented for obtaining a virtual 4-dimensional patient that replicates the intended esthetic treatment. The process involves facial and intraoral scanning to acquire records and software manipulation to enable a virtual waxing of the smile. Once the digital design is complete, patient information can be merged to generate an animated video of the projected rehabilitation, displaying movement and smile dynamics. This strategy provides a noninvasive and reliable diagnostic tool for predicting clinical outcomes.

Comparison of Two Innovative Strategies Using Augmented Reality for Communication in Aesthetic Dentistry: A Pilot Study

During dental prosthetic rehabilitation, communication and conception are achieved using rigorous methodologies such as smile design protocols. The aim of the present pilot study was to compare two innovative strategies that used augmented reality for communication in dentistry. These strategies enable the user to instantly try a virtual smile proposition by taking a set of pictures from different points of view or by using the iPad as an enhanced mirror. Sixth-year dental students (n=18, women = 13, men = 5, mean age = 23.8) were included in this pilot study and were asked to answer a 5-question questionnaire studying the user experience using a visual analog scale (VAS). Answers were converted into a numerical result ranging from 0 to 100 for statistical analysis. Participants were not able to report a difference between the two strategies in terms of handling of the device (p=0.45), quality of the reconstruction (p=0.73), and fluidity of the software (p=0.67). Even if the participants' experience with the enhanced mirror was more often reported as immersive and more likely to be integrated in a daily dental office practice, no significant increase was reported (p=0.15 and p=0.07). Further investigations are required to evaluate time and cost savings in daily practice. Software accuracy is also a major point to investigate in order to go further in clinical applications.