Validation of the Vectra H1 portable three-dimensional photogrammetry system for facial imaging

An exclusionary screening method based on 3D morphometric features to sort commingled atlases and axes

In forensic commingled contexts, when the disarticulation occurs uniquely at the atlantoaxial joint, the correct match of atlas and axis may lead to the desirable assembly of the entire body. Notwithstanding the importance of this joint in such scenarios, no study has so far explored three-dimensional (3D) methodologies to match these two adjoining bones. In the present study, we investigated the potential of re-associating atlas and axis through 3D-3D superimposition by testing their articular surfaces congruency in terms of point-to-point distance (Root Mean Square, RMS). We analysed vertebrae either from the same individual (match) and from different individuals (mismatch). The RMS distance values were assessed for both groups (matches and mismatches) and a threshold value was determined to discriminate matches with a sensitivity of 100%. The atlas and the corresponding axis from 41 documented skeletons (18 males and 23 females), in addition to unpaired elements (the atlas or the axis) from 5 individuals, were superimposed, resulting in 41 matches and 1851 mismatches (joining and non-joining elements). No sex-related significant differences were found in matches and mismatches (p = 0.270 and p = 0.210, respectively), allowing to pool together the two sexes in each group. RMS values ranged between 0.41 to 0.77 mm for matches and between 0.37 and 2.18 mm for mismatches. Significant differences were found comparing the two groups (p < 0.001) and the highest RMS of matches (0.77 mm) was used as the discriminative value that provided a sensitivity of 100% and a specificity of 41%. In conclusion, the 3D-3D superimposition of the atlanto-axial articular facets cannot be considered as a re-association method per se, but rather as a screening one. However, further research on the validation of the 3D approach and on its application to other joints might provide clues to the complex topic of the reassociation of crucial adjoining bones.

Accuracy of Smartphone-Based Three-Dimensional Facial Scanning System: A Systematic Review

BACKGROUND

Recently, the integration of 3D face scanning into smartphones has raised vast interest in plastic surgery. With the release of smartphones featuring 3D face scanning technology, users now can capture detailed 3D models of their faces using their smartphones. However, trueness and precision of this system is less well established.

METHODS

PubMed, Cochrane Library, Embase, ScienceDirect, Scopus, and Web of Science databases were searched for studies evaluating 3D scanning of smartphone devices and conventional 3D imaging systems from January 1, 2017, to June 1, 2023. A qualitative systematic review was conducted by two review authors after independently selecting studies, extracting data, and assessing the risk of bias of included studies.

RESULTS

A total of 11 studies were included, all focusing on the accuracy of smartphone 3D facial scanning. The results show that although smartphones perform poorly on deep and irregular surfaces, they are accurate enough for clinical applications and have the advantage of being economical and portable.

CONCLUSIONS

Smartphone-based 3D facial scanning has been basically validated for clinical application, showing broad clinical application prospects in plastic surgery.

LEVEL OF EVIDENCE II

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors   www.springer.com/00266 .

Comparison of methodologies for craniofacial soft-tissue cephalometrics: The value of virtual reality

BACKGROUND

Myriad options are available for plastic surgeons to perform soft-tissue analysis, which is vital to perioperative evaluation and research. Our objective is to compare the accuracy, precision, and efficiency of the available cephalometric modalities for conducting facial soft-tissue measurements.

METHODS

Twenty soft-tissue facial measurements were performed by 5 measurers with varying experiences on 5 adult subjects, using 6 methods-manual calipers, cone-beam CT, virtual reality (VR), 3D stereophotogrammetry, iPad-based 3D photogrammetry, and 2-dimensional photographs. Measurement sessions were timed and performed in triplicate, for a total of 9000 measurements. Intraclass correlation coefficient (ICC) was calculated for accuracy and one-way ANOVA was used for comparison. The coefficient of variation (CoV) was compared among groups to evaluate the precision of different methods by considering caliper measurements as the gold standard.

RESULTS

ICC among raters was 0.932, indicating excellent reliability. VR was significantly faster than other methods (137 s vs. 217 s for caliper, p < 0.001). CoV was the highest for 2D photographs and the lowest for VR (11.0 vs. 6.4, p < 0.001). The CoV of the caliper was similar to that of other methods, except for 2D photography, which was significantly higher. Measurements with the greatest absolute difference from caliper measurements, across modalities, were those around the eyes (left to right exocanthion), tragion to antitragion, and tragion to exocanthion.

CONCLUSION

2D photography is not an accurate method for cephalometric measurements. VR had the lowest variation between measurements, and was the fastest and equivalent to caliper measurements in accuracy. For studies involving a large number of cephalometrics, VR measurements may be a good option to improve study throughput.

3D Analysis of the Cranial and Facial Shape in Craniosynostosis Patients: A Systematic Review

With increasing interest in 3D photogrammetry, diverse methods have been developed for craniofacial shape analysis in craniosynostosis patients. This review provides an overview of these methods and offers recommendations for future studies. A systematic literature search was used to identify publications on 3D photogrammetry analyses in craniosynostosis patients until August 2023. Inclusion criteria were original research reporting on 3D photogrammetry analyses in patients with craniosynostosis and written in English. Sixty-three publications that had reproducible methods for measuring cranial, forehead, or facial shape were included in the systematic review. Cranial shape changes were commonly assessed using heat maps and curvature analyses. Publications assessing the forehead utilized volumetric measurements, angles, ratios, and mirroring techniques. Mirroring techniques were frequently used to determine facial asymmetry. Although 3D photogrammetry shows promise, methods vary widely between standardized and less conventional measurements. A standardized protocol for the selection and documentation of landmarks, planes, and measurements across the cranium, forehead, and face is essential for consistent clinical and research applications.

Facial Analysis of Patients with Unilateral or Bilateral Cleft Lip and Palate Using 3D Stereophotogrammetry

OBJECTIVES

To evaluate the quantitative values of linear and angular facial anthropometrics in patients with unilateral cleft lip and palate (UCLP) and compare them with those of patients with bilateral cleft lip and palate (BCLP) using three-dimensional (3D) facial imaging.

DESIGN

Retrospective, observational, and cross-sectional study.

SETTING

Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP).

PATIENTS/ PARTICIPANTS

In total, 61 non-syndromic patients with CLP who underwent multidisciplinary treatment and rehabilitated with a prosthesis were enrolled and divided into those with UCLP (G1; n = 31) and those with BCLP (G2; n = 30).

INTERVENTION

Facial images were captured using a 3D camera after landmarks were marked on each patient's face. The software evaluated linear and angular parameters. Statistical tests were applied. Significance was determined as P < 0.05.

MAIN OUTCOME MEASUREMENTS

Overall, 22 linear and 13 angular measurements were evaluated.

RESULTS

The nasal length (P = 0.08), middle third of the face (P = 0.06), base nose width (P < 0.001), nasal root width (P < 0.001), nasal tip angle (P = 0.018), philtrum width (P < 0.001), lower face width (P = 0.039) and midfacial depth (P = 0.040) were significantly higher in G2; the upper cutaneous lip height was significantly higher in G1. Sexual dimorphism was observed except for linear measurements (linear distance between the labiale superius and labiale inferius landmarks, nasal root width, and upper cutaneous lip length) and angular measurements.

CONCLUSIONS

G2 had a greater length and width of nose and nasal root, nasal tip angle, philtrum width, and lower face width, midfacial depth, and midface third than G1. These findings also revealed the presence of sexual dimorphism.

Frontiers in Three-Dimensional Surface Imaging Systems for 3D Face Acquisition in Craniofacial Research and Practice: An Updated Literature Review

Digitalizing all aspects of dental care is a contemporary approach to ensuring the best possible clinical outcomes. Ongoing advancements in 3D face acquisition have been driven by continuous research on craniofacial structures and treatment effects. An array of 3D surface-imaging systems are currently available for generating photorealistic 3D facial images. However, choosing a purpose-specific system is challenging for clinicians due to variations in accuracy, reliability, resolution, and portability. Therefore, this review aims to provide clinicians and researchers with an overview of currently used or potential 3D surface imaging technologies and systems for 3D face acquisition in craniofacial research and daily practice. Through a comprehensive literature search, 71 articles meeting the inclusion criteria were included in the qualitative analysis, investigating the hardware, software, and operational aspects of these systems. The review offers updated information on 3D surface imaging technologies and systems to guide clinicians in selecting an optimal 3D face acquisition system. While some of these systems have already been implemented in clinical settings, others hold promise. Furthermore, driven by technological advances, novel devices will become cost-effective and portable, and will also enable accurate quantitative assessments, rapid treatment simulations, and improved outcomes.

Three-Dimensional Surface Analysis for Preoperative Prediction of Breast Volume: A Validation Study

BACKGROUND

Few studies have examined whether preoperative three-dimensional surface imaging can accurately predict breast volume. Reliably predicting breast volume preoperatively can assist with breast reconstruction planning, patient education, and perioperative risk stratification.

METHODS

The authors conducted a review of patients who underwent mastectomy from 2020 to 2021 and included all patients who had preoperative VECTRA XT three-dimensional imaging. VECTRA Analysis Module (VAM) and VECTRA Body Sculptor (VBS) were used for volumetric analysis using standard anatomical breast borders. Breast weights were obtained intraoperatively. Predictive accuracy was defined as VAM estimates ±10% of mastectomy specimen weight or ±100 g of mastectomy weight.

RESULTS

The study included 179 patients (266 breasts). There was no significant difference ( P = 0.22) between mean mastectomy weight of 620.8 ± 360.3 g and mean VAM estimate of 609.5 ± 361.9 g. Mean VBS estimate was 498.9 ± 337.6 g, which differed from mean mastectomy weight ( P < 0.001). When defining predictive accuracy as ±100 g, 58.7% of VAM and 44.4% of VBS estimates were accurate. Body mass index, body surface area, and ptosis grade significantly affected VAM and VBS breast volume predictions.

CONCLUSIONS

VAM is more accurate at predicting mastectomy weight than VBS, likely because of VAM's analysis of surface topography rather than discrete surface landmarks. Discrepancies between VECTRA estimates and mastectomy weight were likely attributable to differences between surgical mastectomy borders and breast borders used in volumetric analysis. Surgeons should consider the physical characteristics of patients when using three-dimensional imaging.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, I.

Development and Validation of a Comprehensive Perioral Evaluation Method Using Three-Dimensional Stereophotogrammetry

BACKGROUND

The non-invasive three-dimensional (3D) stereophotogrammetry is widely used in anthropometry for medical purpose. Yet, few studies have assessed its reliability on measuring the perioral region.

OBJECTIVES

This study aimed to provide a standardized 3D anthropometric protocol for the perioral region.

METHODS

38 female and 12 male Asians were recruited (mean age 31.6 ± 9.6 years). Two sets of 3D images using the VECTRA 3D imaging system were acquired for each subject, and two measurement sessions for each image were performed independently by two raters. 25 landmarks were identified, and 28 linear, 2 curvilinear, 9 angular and 4 areal measurements were evaluated for intrarater, interrater, and intramethod reliability.

RESULTS

Our results showed high reliability of 3D imaging-based perioral anthropometry by mean absolute difference (0.57 and 0.57 unit), technical error measurement (0.51 and 0.55 unit), relative error of measurement (2.18% and 2.44%), relative technical error of measurement (2.02% and 2.34%), and intraclass correlation coefficient (0.98 and 0.98) for intrarater 1 and intrarater 2 reliability; respectively 0.78 unit, 0.74 unit, 3.26%, 3.06% and 0.97 for interrater reliability; and respectively 1.01 unit, 0.97 unit, 4.74%, 4.57% and 0.95 for intramethod reliability.

CONCLUSIONS

This standardized protocol utilizing 3D surface imaging technologies are feasible and highly reliable in perioral assessment. It could be further applied for diagnostic purpose, surgical planning and therapeutic effect evaluation in clinical practice in relation to perioral morphologies.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Development of Three-Dimensional Breast Scan and Measurement Application Using Laser Imaging Detection and Ranging Sensor on iPhone

SUMMARY

Laser imaging detection and ranging (LiDAR) is a modern three-dimensional (3D) technology that uses a time-of-flight method based on the round-trip time of an infrared laser beam to detect the presence and features of objects. The iPhone 12 Pro is the first smart mobile device with built-in LiDAR sensors. The authors' team developed a software application based on iOS devices with built-in LiDAR sensors for 3D breast scanning and automatically analyzing the breast's geometric measurement. Breast geometry, including midclavicle-to-nipple distance, sternal notch-to-nipple distance, nipple-to-inframammary fold (IMF) distance, distance between nipples, and body circumference on nipple and IMF level were measured using the software application and tapeline. The relative technical error of measurement (rTEM) value was used to calculate the error ratios between the measurements acquired by the software application and those of the tapeline. Good rTEM values ranging from 2.99% to 5.19% were found in the midclavicle-to-nipple distance, sternal notch-to-nipple distance, distance between nipples, nipple-level circumference, and IMF-level circumference. However, there was a poor rTEM value greater than 10% in the nipple-to-IMF distance. The proposed software application using current iOS devices with built-in LiDAR sensors can provide an ideal 3D scanning system that has a low cost burden, good accuracy, portability, and ease of use.

Can smartphones be used for routine dental clinical application? A validation study for using smartphone-generated 3D facial images

OBJECTIVES

To compare the accuracy of smartphone-generated three-dimensional (3D) facial images to that of direct anthropometry (DA) and 3dMD with the aim of assessing the validity and reliability of smartphone-generated 3D facial images for routine clinical applications.

MATERIALS AND METHODS

Twenty-five anthropometric soft-tissue facial landmarks were labelled manually on 22 orthognathic surgery patients (11 males and 11 females; mean age 26.2 ± 5.3 years). For each labelled face, two imaging operations were performed using two different surface imaging systems: 3dMDface and Bellus3D FaceApp. Next, 42 inter-landmark facial measurements amongst the identified facial landmarks were measured directly on each labelled face and also digitally on 3D facial images. The measurements obtained from smartphone-generated 3D facial images (SGI) were statistically compared with those from DA and 3dMD.

RESULTS

SGI had slightly higher measurement values than DA and 3dMD, but there was no statistically significant difference between the mean values of inter-landmark measures across the three methods. Clinically acceptable differences (≤3 mm or ≤5°) were observed for 67 % and 74 % of measurements with good agreement between DA and SGI, and 3dMD and SGI, respectively. An overall small systematic bias of ± 0.2 mm was observed between the three methods. Furthermore, the mean absolute difference between DA and SGI methods was highest for linear (1.41 ± 0.33 mm) as well as angular measurements (3.07 ± 0.73°).

CONCLUSIONS

SGI demonstrated fair trueness compared to DA and 3dMD. The central region and flat areas of the face in SGI are more accurate. Despite this, SGI have limited clinical application, and the panfacial accuracy of the SGI would be more desirable from a clinical application standpoint.

CLINICAL SIGNIFICANCE

The usage of SGI in clinical practice for region-specific macro-proportional facial assessment involving central and flat regions of the face or for patient education purposes, which does not require accuracy within 3 mm and 5° can be considered.

Facial Feminization Surgery: Anatomical Differences, Preoperative Planning, Techniques, and Ethical Considerations

Facial Feminization Surgery (FFS) is a transformative surgical approach aimed at aligning the facial features of transgender women with their gender identity. Through a systematic analysis, this paper explores the clinical differences between male and female facial skeletons along with the craniofacial techniques employed in FFS for each region. The preoperative planning stage is highlighted, emphasizing the importance of virtual planning and AI morphing as valuable tools to be used to achieve surgical precision. Consideration is given to special circumstances, such as procedure sequencing for older patients and silicone removal. Clinical outcomes, through patient-reported outcome measures and AI-based gender-typing assessments, showcase the efficacy of FFS in achieving proper gender recognition and alleviating gender dysphoria. This comprehensive review not only offers valuable insights into the current state of knowledge regarding FFS but also emphasizes the potential of artificial intelligence in outcome evaluation and surgical planning to further advance patient care and satisfaction with FFS.

Evaluation of the Portable Next-Generation VECTRA H2 3D Imaging System for Measuring Upper Eyelid Area and Volume

BACKGROUND

Although a portable 3-dimensional (3D) imaging system has been used for periocular measurement analysis, this system has yet to be tested and validated for periocular area and volume measurements.

OBJECTIVES

The aim of this study was to define the upper eyelid and upper eyelid fold region through a modified landmark strategy and validate a portable 3D imaging system for area and volume measurements in this periocular region.

METHODS

Eighty-one healthy adult Caucasians underwent 3D facial imaging with the VECTRA M3 (static) and VECTRA H2 (portable) 3D imaging systems (Canfield Scientific, Inc., Parsippany, NJ). Subsequently, the upper eyelid and upper eyelid fold regions were selected according to a modified landmark localization strategy. Direct measurements of area and volume were performed to assess intrarater, interrater, intramethod, and intermethod reliability, and to compare the agreement between the 2 devices.

RESULTS

The VECTRA M3 and H2 showed high reliability on upper eyelid area measurements. Excellent intra-, inter-, and intramethod reliability agreements were observed in intraclass correlation coefficient; very good agreement in intrarater reliability was observed in the relative error of measurement (REM) and relative technical error of measurement (rTEM); and good inter- and intramethod reliability were observed in the REM and rTEM. For area measurement of the upper eyelid fold, the intrarater, interrater, and intramethod reliability of the M3 was lower than that of the H2. Both systems had poor intrarater, interrater, and intramethod reliability for volume measurements in the upper eyelid and upper eyelid fold region.

CONCLUSIONS

This new portable 3D imaging system achieved excellent or very good reliability values for standardized direct measurements of the upper eyelid and upper eyelid fold region, although volume measurements seem less reliable.

3D-3D dentition superimposition for individual identification: A study of an Eastern Chinese population

Recently, 3D dental intraoral scanning technology has been developed rapidly and applied widely in everyday dental practice. Since 3D dental scanning could provide valuable personal information, it enabled researchers to develop novel procedures for individual identification through 3D-3D dentition superimposition. This study aimed to test the applicability of this method in an Eastern Chinese population and propose a threshold for personal identification. For this purpose, 40 volunteers were recruited, and the initial 80 (upper and lower) 3D intraoral scans (IOS) were collected. After one year, 80 IOS of these volunteers were repeatedly collected. In addition, the other 120 IOS of 60 patients were extracted from the database. The 3D models were trimmed, aligned, and superimposed via Geomagic Control X software, and then the root mean square (RMS) value of point-to-point distance between the two models was calculated. The superimposition of two IOS belonging to the same individual was considered as a match, and superimposition of two IOS belonging to different individuals was considered as a mismatch. Totally, superimpositions of 80 matches and 3120 mismatches were obtained. Intra- and inter-observer errors were assessed through the calculation of relative technical error of measurement (rTEM). Mann-Whitney U test verified possible statistically significant differences between matches and mismatches (P < 0.05). The rTEM of intra- and inter-observer repeatability analyses was lower than 4.7 %. The range of RMS value was 0.05-0.18 mm in matches and 0.72-2.28 mm in mismatches without overlapping. The percentage of accurate identification reached 100 % in blind test through an arbitrary RMS threshold of 0.45 mm. The results indicated that individual identification through the 3D-3D dentition superimposition was effective in Eastern Chinese population. Successful identification could be achieved with high probability when the RMS value of the point-to-point distance of two dentitions is <0.45 mm.

Morphological and Metrical Relationships Between Sphenoid Sinus and Sella Turcica: Possible Applications in Transnasal Transsphenoidal Surgery

INTRODUCTION

Transsphenoidal surgeries imply the risk of intraoperative lesions to the neurovascular structures surrounding the sphenoid sinus (SS). Aim of the present study is to assess the metrical and morphologic relationships existing between SS and sella turcica (ST).

MATERIALS AND METHODS

Two hundred computed tomography-scans of patients were selected. For each patient volumes of SS were calculated from their 3-dimensional models segmented through ITK-SNAP program. Variants of SS in pneumatisation and sellar diameters [antero-posterior (AP) diameter, depth, and length] were evaluated on each computed tomography-scan. Correlations among different measurements were assessed through Spearman test ( P <0.01), whereas associations between sellar parameters and presence of pneumatisation variants were assessed through Mann-Whitney test ( P <0.01).

RESULTS

In males, pneumatization of the greater wings was related to smaller AP diameter ( P <0.01) and depth of ST ( P <0.01), whereas in females lower values of depth were found in patients with pneumatization of the pterygoid processes ( P <0.01). In both sexes, a positive correlation was found between AP diameter and, respectively, length and depth of ST ( P <0.01), together with a negative correlation between volume of SS and depth of ST ( P <0.01). Lastly, in females a positive correlation was found between age and, respectively, length and depth of ST ( P <0.01).

CONCLUSIONS

The present study highlighted new metrical and morphologic relationships between volume and pneumatisation of SS and diameters of ST. Knowledge of these correlations allows to understand more clearly, in the preoperative setting, the surgical working space. Further studies are needed, especially for what concerns the relationship between sellar measurements and age in females.

Validation of three-dimensional facial imaging captured with smartphone-based photogrammetry application in comparison to stereophotogrammetry system

Statement of problem

The development of facial scanners has improved capabilities to create three-dimensional (3D) virtual patients for accurate facial and smile analysis. However, most of these scanners are expensive, stationary and involve a significant clinical footprint. The use of the Apple iPhone and its integrated "TrueDepth" near-infrared (NIR) scanner combined with an image processing application (app) offers the potential to capture and analyze the unique 3D nature of the face; the accuracy and reliability of which are yet to be established for use in clinical dentistry.

Purpose

This study was designed to validate both the trueness and precision of the iPhone 11 Pro smartphone TrueDepth NIR scanner in conjunction with the Bellus3D Face app in capturing 3D facial images in a sample of adult participants in comparison to the conventional 3dMDface stereophotogrammetry system.

Material and methods

Twenty-nine adult participants were prospectively recruited. Eighteen soft tissue landmarks were marked on each participant's face before imaging. 3D facial images were captured using a 3dMDface system and the Apple iPhone TrueDepth NIR scanner combined with the Bellus3D Face app respectively. The best fit of each experimental model to the 3dMD scan was analyzed using Geomagic Control X software. The root mean square (RMS) was used to measure the "trueness" as the absolute deviation of each TrueDepth scan from the reference 3dMD image. Individual facial landmark deviations were also assessed to evaluate the reliability in different craniofacial regions. The "precision" of the smartphone was tested by taking 10 consecutive scans of the same subject and comparing those to the reference scan. Intra-observer and inter-observer reliabilities were assessed using the intra-class correlation coefficient (ICC).

Results

Relative to the 3dMDface system, the mean RMS difference of the iPhone/Bellus3D app was 0.86 ± 0.31 mm. 97% of all the landmarks were within 2 mm of error compared with the reference data. The ICC for intra-observer reproducibility or precision of the iPhone/Bellus3D app was 0.96, which was classified as excellent. The ICC for inter-observer reliability was 0.84, which was classified as good.

Conclusions

These results suggest that 3D facial images acquired with this system, the iPhone TrueDepth NIR camera in conjunction with the Bellus3D Face app, are clinically accurate and reliable. Judicious use is advised in clinical situations that require high degrees of detail due to a lack of image resolution and a longer acquisition time. Generally, this system possesses the potential to serve as a practical alternative to conventional stereophotogrammetry systems for use in a clinical setting due to its accessibility and relative ease of use and further research is planned to appraise its updated clinical use.

Optimization of a Novel Automated, Low Cost, Three-Dimensional Photogrammetry System (PHACE)

Introduction

Clinical tools are neither standardized nor ubiquitous to monitor volumetric or morphological changes in the periorbital region and ocular adnexa due to pathology such as oculofacial trauma, thyroid eye disease, and the natural aging process. We have developed a low-cost, three dimensionally printed PHotogrammetry for Automated CarE (PHACE) system to evaluate three-dimensional (3D) measurements of periocular and adnexal tissue.

Methods

The PHACE system uses two Google Pixel 3 smartphones attached to automatic rotating platforms to image a subject's face through a cutout board patterned with registration marks. Photographs of faces were taken from many perspectives by the cameras placed on the rotating platform. Faces were imaged with and without 3D printed hemispheric phantom lesions (black domes) affixed on the forehead above the brow. Images were rendered into 3D models in Metashape (Agisoft, St. Petersburg, Russia) and then processed and analyzed in CloudCompare (CC) and Autodesk's Meshmixer. The 3D printed hemispheres affixed to the face were then quantified within Meshmixer and compared to their known volumes. Finally, we compared digital exophthalmometry measurements with results from a standard Hertel exophthalmometer in a subject with and without an orbital prosthesis.

Results

Quantification of 3D printed phantom volumes using optimized stereophotogrammetry demonstrated a 2.5% error for a 244μL phantom, and 7.6% error for a 27.5μL phantom. Digital exophthalmometry measurements differed by 0.72mm from a standard exophthalmometer.

Conclusion

We demonstrated an optimized workflow using our custom apparatus to analyze and quantify oculofacial volumetric and dimensions changes with a resolution of 244μL. This apparatus is a low-cost tool that can be used in clinical settings to objectively monitor volumetric and morphological changes in periorbital anatomy.

Comparison of a custom Photogrammetry for Anatomical CarE (PHACE) system with other Low- Cost Facial Scanning Devices

Purpose

To compare a custom Photogrammetry for Anatomical CarE (PHACE) system with other cost-effective 3-dimensional (3D) facial scanning systems to objectively characterize morphology and volume of periorbital and adnexal anatomy.

Methods

The imaging systems evaluated include the low-cost custom PHACE system and commercial software product for the iPhone called Scandy Pro (iScandy) application (Scandy, USA), and the mid-priced Einscan Pro 2X (Shining3D Technologies, China) device and Array of Reconstructed Cameras 7 (ARC7) facial scanner (Bellus3D, USA). Imaging was performed on a manikin facemask and humans with various Fitzpatrick scores. Scanner attributes were assessed using mesh density, reproducibility, surface deviation, and emulation of 3D printed phantom lesions affixed above the superciliary arch (brow line).

Results

The Einscan served as a reference for lower cost imaging systems because it qualitatively and quantitatively renders facial morphology with the highest mesh density, reproducibility (0.13 ± 0.10 mm), and volume recapitulation (approximately 2% of 33.5 μL). Compared to the Einscan, the PHACE system (0.35 ± 0.03 mm, 0.33 ± 0.16 mm) demonstrated non-inferior mean accuracy and reproducibility root mean square (RMS) compared to the iScandy (0.42 ± 0.13 mm, 0.58 ± 0.09 mm), and significantly more expensive ARC7 (0.42 ± 0.03 mm, 0.26 ± 0.09 mm). Similarly, the PHACE system showed non-inferior volumetric modeling when rendering a 124 μL phantom lesion compared to the iScandy and more costly ARC7 (mean percent difference from the Einscan: 4.68 ± 3.73%, 9.09 ± 0.94%, and 21.99 ± 17.91% respectively).

Conclusions

The affordable PHACE system accurately measures periorbital soft tissue as well as other established mid-cost facial scanning systems. Additionally, the portability, affordability, and adaptability of PHACE can facilitate widespread adoption of 3D facial anthropometric technology as an objective measurement tool in ophthalmology.

Three-dimensional quantification of skeletal midfacial complex symmetry

PURPOSE

Quantification of skeletal symmetry in a healthy population could have a strong impact on the reconstructive surgical procedures where mirroring of the contralateral healthy side acts as a clinical reference for the restoration of unilateral defects. Hence, the aim of this study was to three-dimensionally assess the symmetry of skeletal midfacial complex in skeletal class I patients.

METHODS

A sample of 100 cone beam computed tomography (CBCT) scans (50 males, 50 females; age range: 19-40 years) were recruited. Automated segmentation of the skeletal midfacial complex was performed to create a three-dimensional (3D) virtual model using a convolutional neural network (CNN)-based segmentation tool. Thereafter, the segmented model was mirrored and registered to quantify skeletal symmetry using a color-coded conformance mapping based on a surface part comparison analysis.

RESULTS

Overall, the mean and root-mean-square (RMS) differences between complete true and mirrored models were 0.14 ± 0.12 and 0.87 ± 0.21 mm, respectively. Female patients had a significantly more symmetrical midfacial complex (mean difference: 0.11 ± 0.1 mm, RMS: 0.81 ± 0.17 mm) compared to male patients (mean difference: 0.16 ± 0.13 mm, RMS: 0.94 ± 0.23 mm). No significant difference existed between left and right sides irrespective of the patient's gender.

CONCLUSION

The comparison between true and mirrored complete and left/right split midfacial complex showed symmetry within a clinically acceptable range of 1 mm, which justifies the applicability of using the mirroring technique. The presented data could act as a reference guide for surgeons during planning of reconstructive surgical procedures and outcome assessment at follow-up.

Morphometric Assessment of Facial Morphology in Infants with Orofacial Clefts up to two Years of Age: A Three-Dimensional Cross-Sectional Study

OBJECTIVE

To assess modelled facial development of infants with unilateral cleft lip (CL) and cleft lip and palate (UCLP) compared to controls up to two years of age.

DESIGN AND PARTICIPANTS

A total of 209 facial images of children (CL: n = 37; UCLP: n = 39; controls: n = 137) were obtained in four age categories (T0 = 0.2-0.5; T1 = 0.6-1.0; T2 = 1.1-1.5; T3 = 1.6-2.0 years) and were evaluated using stereophotogrammetry and geometric morphometry. All patients underwent lip surgery before T0, patients with UCLP underwent palatoplasty (T0, T1 before palatoplasty; T2, T3 after palatoplasty).

RESULTS

In patients with CL, the forehead was significantly retracted (p ≤ 0.001), while the supraorbital and ocular regions were prominent (p ≤ 0.001). The oronasal region appeared convex (p ≤ 0.001). The lower lip and chin were non-significantly protruded. In patients with UCLP, a significantly retracted forehead and prominent supraorbital region were apparent (p ≤ 0.001). A retrusive oronasal region (p ≤ 0.001) was observed in the middle face. The chin was anteriorly protruded (p ≤ 0.01). No progression of deviations was found with increasing age. After the first year, a slight improvement in the morphological features became apparent. The shape variability of the clefts and controls overlapped, suggesting a comparable modelled facial development.

CONCLUSIONS

The facial morphology of individuals with cleft was comparable to the norm. Shape deviation was apparent in the oronasal region, forehead, and chin, which minimised with increasing age even in complete clefts.

Accuracy of low-cost alternative facial scanners: a prospective cohort study

INTRODUCTION

Three-dimensional facial scans have recently begun to play an increasingly important role in the peri-therapeutic management of oral and maxillofacial and head and neck surgery cases. Face scan images can be generated by optical facial scanners utilizing line-laser, stereophotography, or structured light modalities, as well as from volumetric data: for example, from cone beam computed tomography (CBCT). This study aimed to evaluate whether two low-cost procedures for the creation of three-dimensional face scan images were capable of producing sufficiently accurate data sets for clinical analysis.

MATERIALS AND METHODS

Fifty healthy volunteers were included in the study. Two test objects with defined dimensions (Lego bricks) were attached to the forehead and the left cheek of each volunteer. Facial anthropometric values (i.e., the distances between the medial canthi, the lateral canthi, the nasal alae, and the angles of the mouth) were first measured manually. Subsequently, face scans were performed with a smart device and manual photogrammetry and the values obtained were compared with the manually measured data sets.

RESULTS

The anthropometric distances deviated, on average, 2.17 mm from the manual measurements (smart device scanning deviation 3.01 mm, photogrammetry deviation 1.34 mm), with seven out of eight deviations being statistically significant. For the Lego brick, from a total of 32 angles, 19 values demonstrated a significant difference from the original 90° angles. The average deviation was 6.5° (smart device scanning deviation 10.1°, photogrammetry deviation 2.8°).

CONCLUSION

Manual photogrammetry demonstrated greater accuracy when creating three-dimensional face scan images; however, smart devices are more user-friendly. Dental professionals should monitor camera and smart device technical improvements carefully when choosing and adequate technique for 3D scanning.

A novel standardized approach for the 3D evaluation of upper eyelid area and volume

Background

Three-dimensional (3D) surface imaging and morphometrics are becoming the preferred craniofacial surface imaging modality. However, as a unique advantage of 3D imaging, areal and volumetric measurements have been rarely conducted and validated for evaluating soft tissue change in the periocular region, especially the upper eyelids. Therefore, based on an existing periocular landmark identification strategy, we proposed a novel modified method to define a standardized upper eyelid region for areal and volumetric measurements and validate its reliability for future clinical application.

Methods

Forty-four healthy adult volunteers were enrolled in this cross-sectional study. Three-dimensional facial images were taken with a 3D imaging system. Subsequently, the upper eyelid region selection and areal and volumetric measurements were conducted using a modified landmarks localization strategy to evaluate their intrarater, interrater, and intramethod reliability.

Results

Areal measurement of the upper eyelid revealed highly reliable outcomes for intraclass correlation coefficient (ICC), mean absolute difference (MAD), relative error measurement (REM), technical error of measurement (TEM), and relative technical error of measurement (%TEM) of 0.982, 0.1620 cm², 2.9%, 0.1510 cm², and 2.7% for intrarater reliability, respectively; 0.969, 0.2076 cm², 3.7%, 0.1930 cm², and 3.5% for interrater reliability, respectively; and 0.917, 0.3636 cm², 6.5%, 0.3354 cm², and 6.0% for intramethod reliability, respectively. Unsatisfactory results were found for the volumetric measurement of the upper eyelid: the ICC, MAD, REM, TEM, and %TEM estimates for intrarater reliability were 0.992, 0.2299 mL, 10.3%, 0.2414 mL, and 10.8%, respectively; for interrater reliability, these values were 0.985, 0.2749 mL, 12.3%, 0.3253 mL, and 14.6%, respectively; and for intramethod reliability, these values were 0.433, 1.6716 mL, 77.9%, 2.0615 mL, and 96.1%, respectively.

Conclusions

This is the first study to propose a standardized upper eyelid region selection strategy and simultaneously validate its reliability for 3D areal and volumetric measurements. This study confirmed the high-level reliability of areal measurement and poor reliability of volumetric measurement based on direct measurements using a single image, which may provide better results when this method is combined with the image overlapping and registration procedure. However, this is subject to further validation. Nonetheless, this method could provide quantitative areal and volumetric data on the upper eyelids and might have widespread application potential in the future.

Accuracy and Reliability of 3D Imaging for Facial Movement Evaluation: Validation of the VECTRA H1

Three-dimensional imaging can be used to obtain objective assessments of facial morphology that is useful in a variety of clinical settings. The VECTRA H1 is unique in that it is relatively inexpensive, handheld, and does not require standardized environmental conditions for image capture. Although it provides accurate measurements when imaging relaxed facial expressions, the clinical evaluation of many disorders involves the assessment of facial morphology when performing facial movements. The aim of this study was to assess the accuracy and reliability of the VECTRA H1, specifically when imaging facial movement.

Methods

The accuracy, intrarater, and interrater reliability of the VECTRA H1 were assessed when imaging four facial expressions: eyebrow lift, smile, snarl, and lip pucker. Fourteen healthy adult subjects had the distances between 13 fiducial facial landmarks measured at rest and the terminal point of each of the four movements by digital caliper and by the VECTRA H1. Intraclass correlation and Bland-Altman limits of agreement were used to determine agreement between measures. The agreement between measurements obtained by five different reviewers was evaluated by intraclass correlation to determine interrater reliability.

Results

Median correlation between digital caliper and VECTRA H1 measurements ranged from 0.907 (snarl) to 0.921 (smile). Median correlation was very good for both intrarater (0.960-0.975) and interrater reliability (0.997-0.999). The mean absolute error between modalities, and both within and between raters was less than 2 mm for all movements tested.

Conclusion

The VECTRA H1 met acceptable standards for the assessment of facial morphology when imaging facial movements.

Three-dimensional quantitative analysis of temporal region morphology in Chinese young adult

Background

Temporal filling is commonly used to correct temporal depression. However, there is a lack of quantitative criteria for pre- and post-operative evaluations. The use of three-dimensional scanning may help improving the success of temporal filling by providing quantitative assessments. The study aimed to compare the results of qualitative morphological evaluation of the temporal region with a quantitative, numerical analysis of the temporal difference value (TDV).

Methods

We enrolled twenty-six male and forty-nine female volunteers aged 18 to 29 years. Facial images were acquired in OBJ format using 3dMD facial stereo-photography. The morphologies of the temporal regions were separately evaluated by four researchers in the form of two-dimensional (2D) images. Results were classified as either aesthetic or unaesthetic. The quantitative evaluation of the temporal region was then conducted. First, the temporal region was trimmed out from the original 3D image into a new OBJ file. Second, interpolation was used to construct a smooth, adapted surface. Third, a mathematical model of temporal region flatness denoted as the TDV, which was defined as the sum of the Euclidean distances of all 3D points between the constructed surface and the temporal-region OBJ file. The classification of each sample was compared with its TDV to verify the mathematical model's validity. The cutoff threshold and prediction accuracy of this mathematical model were calculated.

Results

The cutoff threshold between aesthetic and unaesthetic TDV was found to be 24.66 for males and 28.11 for females. The prediction accuracy rate was 0.73 for men and 0.73 for women.

Conclusion

The method has high overlap and good repeatability and minimizes the influence of subjective aesthetics on morphological judgment. TDV has a certain reference value for clinical temporal region evaluation.

Advancement in Human Face Prediction Using DNA

The rapid improvements in identifying the genetic factors contributing to facial morphology have enabled the early identification of craniofacial syndromes. Similarly, this technology can be vital in forensic cases involving human identification from biological traces or human remains, especially when reference samples are not available in the deoxyribose nucleic acid (DNA) database. This review summarizes the currently used methods for predicting human phenotypes such as age, ancestry, pigmentation, and facial features based on genetic variations. To identify the facial features affected by DNA, various two-dimensional (2D)- and three-dimensional (3D)-scanning techniques and analysis tools are reviewed. A comparison between the scanning technologies is also presented in this review. Face-landmarking techniques and face-phenotyping algorithms are discussed in chronological order. Then, the latest approaches in genetic to 3D face shape analysis are emphasized. A systematic review of the current markers that passed the threshold of a genome-wide association (GWAS) of single nucleotide polymorphism (SNP)-face traits from the GWAS Catalog is also provided using the preferred reporting items for systematic reviews and meta-analyses (PRISMA), approach. Finally, the current challenges in forensic DNA phenotyping are analyzed and discussed.

Digital pair-matching of iliac bones: pilot study on a three-dimensional approach with models acquired through stereophotogrammetry

Three-dimensional (3D) pair-matching has brought about an innovative approach for the analysis of commingled skeletal remains, and it has been tested on bone models acquired through CT and laser scans. Here, 3D models of 40 innominate bones (20 left and 20 right) of 20 documented male individuals from a cemeterial skeletal collection were acquired through a stereophotogrammetric device (VECTRA M3, Canfield Scientific, Inc.). The ventral iliac surface was chosen as the anatomical region of interest (ROI) for the analysis. Each left ROI was mirrored and superimposed on the matching right ROI (contralateral element from the same individual) and mismatching ROIs (contralateral elements from different individuals). The point-to-point distance between models was calculated through the Vectra Analysis Module (VAM) software and the root mean square (RMS) point-to-point distance value was used to evaluate the sorting performance of the method, in terms of sensitivity and specificity rates. Differences in RMS between matches and mismatches were investigated through a Student's t test (p < 0.05). The state of preservation of the remains was assessed following an index of anatomical completeness and differences in RMS distances of true matches according to different anatomical completeness were assessed through the Mann-Whitney test (p < 0.05). RMS point-to-point distances of matches and mismatches were significantly different (p < 0.01), being the matches lower than mismatches. The RMS threshold of 2.9 mm identified all the true pairs; the test was 100% sensitive and 51% specific. The RMS of matches with a better state of preservation are significantly lower than the less preserved matches (p < 0.05). In general, a low RMS distance value may indicate a true match, being it to be further verified. The 3D approach for sorting innominate bones provides a valid screening test that could complete subjective and osteometric methods with numerical evidence of the match. Preliminary data suggest a possible relation between RMS distance values and taphonomic condition, which would benefit from further research.

3D-3D Superimposition of Pubic Bones: Expanding the Anthropological Toolkit for the Pair-Matching of Commingled Skeletal Remains

Virtual anthropology (VA) has recently produced an additional tool for the analysis of commingled remains and is based on the distance analysis between three-dimensional (3D) models of bones. To date, the pair-matching of the innominate bone through a 3D approach remains partially unexplored. Here, 44 abdominal CT scans (22 males and 22 females) were selected from a hospital database, and the pubic bones were segmented through ITK-SNAP software. The models were hollowed with Viewbox4 to minimize the amount of trabecular bone. The left pubic bones were mirrored and superimposed on the right ones, according to the smallest point-to-point difference between the two surfaces through VAM software. RMS distances between models were calculated through VAM, producing RMS values for 20 matches and 420 mismatches for each sex group. Differences in RMS distance values between matches and mismatches were investigated through Mann−Whitney tests (p < 0.05); the repeatability of the procedure was assessed through absolute and relative technical error measurement (TEM and rTEM). RMS distance values of matches and mismatches were significantly different (p < 0.01) in both groups. The method yielded optimal results with high sensitivity (100.0%) and specificity (99.8% in males, 98.8% in females) rates according to the chosen threshold. This project contributes to the research field of VA with a valuable adjunct that may bolster and strengthen the results of the current visual and osteometric methods through a multidisciplinary approach.

Accuracy of three-dimensional optical devices for facial soft-tissue measurement in clinical practice of stomatology: A PRISMA systematic review

BACKGROUND

The accuracy of 3-dimensional (3D) optical devices for facial soft-tissue measurement is essential to the success of clinical treatment in stomatology. The aim of the present systematic review was to summarize the accuracy of 3D optical devices used for facial soft-tissue assessment in stomatology.

METHODS

An extensive systematic literature search was performed in the PubMed/MEDLINE, Embase, Scopus and Cochrane Library databases for studies published in the English language up to May 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. Peer-reviewed journal articles evaluating the facial soft-tissue morphology by 3D optical devices were included. The risk of bias was performed using the Quality Assessment Tool for Diagnostic Accuracy Studies-2 guidelines by the 2 reviewers. The potential publication bias was analyzed using the Review Manager software.

RESULTS

The query returned 1853 results. A total of 38 studies were included in this review. Articles were categorized based on the principle of devices: laser-based scanning, structured-light scanning, stereophotogrammetry and red, green, blue-depth camera.

CONCLUSION

Overall, the 3D optical devices demonstrated excellent accuracy and reliability for facial soft-tissue measurement in stomatology. red, green, blue-depth camera can collect accurate static and dynamic 3D facial scans with low cost and high measurement accuracy. Practical needs and availability of resources should be considered when these devices are used in clinical settings.

Facial Scanning Accuracy with Stereophotogrammetry and Smartphone Technology in Children: A Systematic Review

The aim of the study was to systematically review and compare the accuracy of smartphone scanners versus stereophotogrammetry technology for facial digitization in children. A systematic literature search strategy of articles published from 1 January 2010 to 30 August 2022 was adopted through a combination of Mesh terms and free text words pooled through boolean operators on the following databases: PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and OpenGrey. Twenty-three articles met the inclusion criteria. Stationary stereophotogrammetry devices showed a mean accuracy that ranged from 0.087 to 0.860 mm, portable stereophotogrammetry scanners from 0.150 to 0.849 mm, and smartphones from 0.460 to 1.400 mm. Regarding the risk of bias assessment, fourteen papers showed an overall low risk, three articles had unclear risk and four articles had high risk. Although smartphones showed less performance on deep and irregular surfaces, all the analyzed devices were sufficiently accurate for clinical application. Internal depth-sensing cameras or external infrared structured-light depth-sensing cameras plugged into smartphones/tablets increased the accuracy. These devices are portable and inexpensive but require greater operator experience and patient compliance for the incremented time of acquisition. Stationary stereophotogrammetry is the gold standard for greater accuracy and shorter acquisition time, avoiding motion artifacts.

Facial scanning technologies in the era of digital workflow: A systematic review and network meta-analysis

PURPOSE

The aim of this network meta-analysis is to evaluate the accuracy of various face-scanning technologies in the market, with respect to the different dimensions of space (x, y, and z axes). Furthermore, attention will be paid to the type of technologies currently used and to the best practices for high-quality scan acquisition.

MATERIAL AND METHODS

The review was conducted following the PRISMA guidelines and its updates. A thorough search was performed using the digital databases MEDLINE, PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials by entering research lines or various combinations of free words. The main keywords used during the search process were "photogrammetry", "laser scanner", "optical scanner", "3D, and "face".

RESULTS

None of the included technologies significantly deviated from direct anthropometry. The obtained mean differences in the distances between the considered landmarks range from 1.10 to -1.74 mm.

CONCLUSION

Limiting the movements of the patient and scanner allows for more accurate facial scans with all the technologies involved. Active technologies such as laser scanners (LS), structured light (SL), and infrared structured light (ISL) have accuracy comparable to that of static stereophotogrammetry while being more cost-effective and less time-consuming.

Quantification of Facial Allograft Edema During Acute Rejection: A Software-Based 3-Dimensional Analysis

BACKGROUND

Acute rejection (AR) is a common complication in facial transplant (FT) patients associated with allograft edema and erythema. Our study aims to demonstrate the feasibility of using software-based 3-dimensional (3D) facial analysis to quantify edema as it resolves during/after AR treatment in an FT patient.

METHODS

Our patient is a 23-year-old man who underwent a face and bilateral hand allotransplant in August 2020. The Vectra H1 (Canfield, Fairfield, NJ) portable scanner was used to capture 3D facial images at 8 time points between postoperative day (POD) 392 and 539. The images were analyzed with the Vectra Software using a rejection-free image (POD 539) as a control.

RESULTS

Edema increased in the periorbital, lower third, and submandibular regions before AR treatment (POD 392-415). At POD 448, total facial edema was reduced to near baseline values in response to plasmapheresis and thymoglobulin (+156.94 to +28.2 mL). The fastest and most notable response to treatment was seen in the periorbital region, while some edema remained in the submandibular (+19.79 mL) and right lower third (+8.65 mL) regions. On POD 465, after the initial improvement, the edema increased but was resolved with steroid use. Facial edema did not correlate with the histopathological evaluation in our patient.

CONCLUSIONS

We demonstrated the feasibility of analyzing 3D facial images to quantify edema during/after AR treatment in an FT patient. Our analysis detected edema changes consistent with AR followed by an improvement after treatment. This technology shows promise for noninvasive monitoring of FT patients.

Robustness of Distinctive Facial Features in Prader-Willi Syndrome: A Stereophotogrammetric Analysis and Association with Clinical and Biochemical Markers in Adult Individuals

Background: Prader-Willi syndrome (PWS) is a rare genomic imprinting disorder associated to a complex neurodevelopmental phenotype and a distinctive facial appearance. The study investigated the relationships between the quantitative facial dysmorphism in PWS and clinical and biochemical markers of the disease and its treatment. Methods: Facial images of 15 Caucasian adult individuals with PWS (8 males, 42 ± 5 years; 7 females, 37 ± 8 years; BMI 38.87 ± 8.92 kg/m2) were acquired through stereophotogrammetry. From the 3D coordinates of 38 landmarks, linear distances and angles were calculated; they were expressed as z-score values by referring to 403 healthy subjects matched for age and sex and compared by Student’s t-test with Bonferroni correction for multiple testing. Patients underwent auxological and biochemical assessment of endocrine/metabolic dysfunction and nocturnal respiratory function. An exploratory correlation analysis was performed to investigate their associations with the facial phenotype; uncorrected p-values were used. Results and Conclusions: Individuals with PWS showed decreased bifrontal diameter, facial depths, palpebral fissures, mandibular ramus length, lower vermillion height, and modified relative position of exocanthia and nasion. Since these characteristics did not show any associations with clinical and biochemical markers of PWS, they could constitute robust distinctive facial features and contribute to the diagnosis of the disorder. Individuals with PWS showed also a larger mandibular width with smaller gonial angles, thinner upper vermillion, greater inclination of the orbit relative to the Frankfurt plane, and a smaller angle of the auricles versus the facial midplane. Relationships between these facial anthropometric features and body composition, glucidic metabolism indexes, nocturnal hypoxemia episodes, or duration of GH treatment were found, suggesting their potentially useful role in the clinical monitoring and management of the disease. However, they need to be confirmed by subsequent dedicated studies.

Validation of Vectra 3D Imaging Systems: A Review

Aim: Three-dimensional facial imaging systems are a useful tool that is gradually replacing two-dimensional imaging and traditional anthropometry with calipers. In this varied and growing landscape of new devices, Canfield (Canfield Scientific, Parsippany, NJ, USA) has proposed a series of static and portable 3D imaging systems. The aim of this systematic review was to evaluate the current literature regarding the validation of Canfield’s Vectra imaging systems. Materials and Methods: A search strategy was developed on electronic databases including PubMed, Web of Science and Scopus by using specific keywords. After the study selection phase, a total of 10 articles were included in the present review. Results: A total of 10 articles were finally included in the present review. For six articles, we conducted a validation of the Vectra static devices, focusing especially on the Vectra M5, Vectra M3 and Vectra XT. For four articles, we validated the Vectra H1 portable system. Conclusions: All of the reviewed articles concluded that Canfield’s Vectra 3D imaging systems are capable of capturing accurate and reproducible stereophotogrammetric images. Minor errors were reported, particularly in the acquisition of the perioral region, but all the evaluated devices are considered to be valid and accurate tools for clinicians.

Nonsubjective Assessment of Shape, Volume and Symmetry during Breast Augmentation with Handheld 3D Device

Three-dimensional Surface Imaging (3DSI) has become a valuable tool for planning and documenting surgical procedures. Although surface scanners have allowed for a better understanding of breast shape, size, and asymmetry during patient consultation, its use has not been included in intraoperative assessment so far. Validation of the reliability of the intraoperative use of a portable handheld 3DSI equipment as a tool to evaluate morphological changes during breast augmentation surgery. The patients who underwent bilateral subpectoral breast augmentation through an inframammary incision were included in this study. Intraoperative 3DSI was performed with the Artec Eva device, allowing for visualization of the surgical area before incision, after use of breast sizers and implant, and after wound closure. Intraoperatively manual measurements of breast distances and volume changes due to known sizer and implant volumes were in comparison with digital measurements calculated from 3DSI of the surgical area. Bilateral breasts of 40 patients were 3D photographed before incision and after suture successfully. A further 108 implant sizer uses were digitally documented. There was no significant difference between manual tape measurement and digital breast distance measurement. Pre- to postoperative 3D volume change showed no significant difference to the known sizer and implant volume.

Portable three-dimensional imaging to monitor small volume enhancement in face, vulva, and hand: A comparative study

Multiple handheld three-dimensional (3D) systems are available on the market, but data regarding their use in detecting small volumes are limited. The aim of this study was to compare different portable 3D technologies in detecting small volumetric enhancement on a mannequin model and a series of patients. Five portable 3D systems (Artec Eva, Crisalix, Go!Scan, LifeViz Mini, and Vectra H1) were tested in a controlled environment with standardised volumes and in a clinical setting with patients undergoing small volume fat grafting to face, vulva, and hand. Accuracy was assessed with absolute and relative technical error measurement (TEM and rTEM); precision with intra- and inter-observer reliability (r_p and ICC); and usability in clinical practice with the following parameters: portability, suitability of use in operating theatre/clinic, ease of use of hardware and software, speed of capture, image quality, patient comfort, and cost. All tested devices presented overall good accuracy in detecting small volumetric changes ranging from 0.5 to 4 cc. Structured-light laser scanners (Artec Eva and Go!Scan) showed high accuracy, but their use in clinical practice was limited by longer capture time, multiple wiring, and complex software for analysis. Crisalix was considered the most user-friendly, less bothering for patients, and truly portable, but its use was limited to the face because the software does not include vulva and hand. Three-dimensional technologies exploiting the principle of passive stereophotogrammetry such as LifeViz Mini and Vectra H1 were the most versatile for assessing accurately multiple body areas, representing overall the best long-term value for money. Therefore, 3D portable technology is a non-invasive, accurate, and reproducible method to assess the volumetric outcome after facial, vulval, and hand injectables. The choice of the 3D system should be based on the clinical need and resources available.

Navigation of frameless fixation for gamma knife radiosurgery using fixed augmented reality

Augmented reality (AR) offers a new medical treatment approach. We aimed to evaluate frameless (mask) fixation navigation using a 3D-printed patient model with fixed-AR technology for gamma knife radiosurgery (GKRS). Fixed-AR navigation was developed using the inside-out method with visual inertial odometry algorithms, and the flexible Quick Response marker was created for object-feature recognition. Virtual 3D-patient models for AR-rendering were created via 3D-scanning utilizing TrueDepth and cone-beam computed tomography (CBCT) to generate a new GammaKnife Icon™ model. A 3D-printed patient model included fiducial markers, and virtual 3D-patient models were used to validate registration accuracy. Registration accuracy between initial frameless fixation and re-fixation navigated fixed-AR was validated through visualization and quantitative method. The quantitative method was validated through set-up errors, fiducial marker coordinates, and high-definition motion management (HDMM) values. A 3D-printed model and virtual models were correctly overlapped under frameless fixation. Virtual models from both 3D-scanning and CBCT were enough to tolerate the navigated frameless re-fixation. Although the CBCT virtual model consistently delivered more accurate results, 3D-scanning was sufficient. Frameless re-fixation accuracy navigated in virtual models had mean set-up errors within 1 mm and 1.5° in all axes. Mean fiducial marker differences from coordinates in virtual models were within 2.5 mm in all axes, and mean 3D errors were within 3 mm. Mean HDMM difference values in virtual models were within 1.5 mm of initial HDMM values. The variability from navigation fixed-AR is enough to consider repositioning frameless fixation without CBCT scanning for treating patients fractionated with large multiple metastases lesions (> 3 cm) who have difficulty enduring long beam-on time. This system could be applied to novel GKRS navigation for frameless fixation with reduced preparation time.

Implants Versus Lipograft: Analysis of Long-Term Results Following Congenital Breast Asymmetry Correction

Aims

Congenital breast asymmetry represents a particular challenge to the classic techniques of plastic surgery given the young age of patients at presentation. This study reviews and compares the long-term results of traditional breast augmentation using silicone implants and the more innovative technique of lipografting.

Methods

To achieve this, we not only captured subjective parameters such as satisfaction with outcome and symmetry, but also objective parameters including breast volume and anthropometric measurements. The objective examination was performed manually and by using the Vectra^® H2 photogrammetry scanning system.

Results

Differences between patients undergoing either implant augmentation or lipograft were revealed not to be significant with respect to patient satisfaction with surgical outcome (p = 0.55) and symmetry (p = 0.69). Furthermore, a breast symmetry of 93 % was reported in both groups. Likewise, no statistically significant volume difference between the left and right breasts was observed in both groups (p < 0.41). However, lipograft patients needed on average 2.9 procedures to achieve the desired result, compared with 1.3 for implant augmentation. In contrast, patients treated with implant augmentation may require a number of implant changes during their lifetime.

Conclusion

Both methods may be considered for patients presenting with congenital breast asymmetry.

Level of Evidence III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Validation of the Portable Next-Generation VECTRA H2 3D Imaging System for Periocular Anthropometry

Purpose

Portable three-dimensional imaging systems are becoming increasingly common for facial measurement analysis. However, the reliability of portable devices may be affected by the necessity to take three pictures at three time points. The purpose of this study was to evaluate the effectiveness of portable devices for assessing the periocular region.

Methods

In 60 Caucasian volunteers (120 eyes), four facial scans (twice for each instrument) using the portable VECTRA H2 and static VECTRA M3 devices were performed; patients' heads were kept straight, looking ahead, with a neutral facial expression. One assessor set 52 periocular landmarks in the periocular area of each image and subsequently assessed intra- and inter-device reliability by comparing two within-device measurements and one between-device measurement, respectively.

Results

The mean absolute difference (MAD) (0.13 and 0.12 units), relative error of measurement (REM) (0.61 and 0.68%), technical error of measurement (TEM)(1.02 and 0.80 units), relative TEM (rTEM) (5.51 and 4.43%), and intraclass correlation coefficient (ICC) (0.89, 0.89) showed good intra-device reliability for M3 and H2; MAD (0.63, 0.62 units), REM (2.83, 2.69%), TEM (1.31, 1.10 units), rTEM (7.62, 5.57%), and ICC (0.79, 0.83) indicated that inter-device reliability deteriorated compared to intra-device reliability and that the inter-device reliability of the first scan (moderate) was lower than that of the average of the two scans (good).

Conclusions

The portable VECTRA H2 device proved reliable in assessing most periocular linear distances, curve distances, and angles; some improvement in inter-device reliability can be achieved by using the average of two scans.

Applications of three-dimensional surgical planning in facial feminization surgery: A systematic review

BACKGROUND

Despite some reports that have shown an increase in safety, efficiency, and accuracy during feminizing craniofacial procedures utilizing three-dimensional (3D) technology, there are no reports summarizing the available evidence on this matter for facial feminization surgery (FFS). Here, we aimed to systematically review the application of 3D technology on FFS.

METHODS

We conducted a comprehensive search across PubMed, SCOPUS, Ovid MEDLINE®, Web of Science, and ScienceDirect looking for studies reporting the use of 3D surgical planning in the setting of FFS following the PRISMA guidelines. We extracted data on photographic assessment, imaging, surgical application, and surgical technique and outcomes.

RESULTS

This review included 10 studies comprising 1473 transgender female patients and 50 cadaveric cranial specimens. Four studies employed virtual surgical planning (VSP) and the concomitant use of prefabricated cutting guides. One study reported the implementation of 3D VSP using a female skull as a reference. One study used computer-aided design cutting guides and custom plates for FFS. Standardized incorporation of 3D printed models allowed for preoperative planning in three studies. Three studies reported VSP using 3D reconstruction of CT images, but without the use of 3D printing. Three studies used 3D photography with specialized camera technology to enrich clinical documentation and provide a comprehensive facial analysis of soft tissue. Accuracy ranged from 85.7% to 97%. Morbidity ranged from 0% to 12.5%.

CONCLUSION

Based on this data, we believe 3D VSP has promising outcomes in terms of accuracy and low morbidity, encouraging its implementation in FFS. However, further prospective double-arm cohort studies are required.

3D‐3D facial registration method applied to personal identification: Does it work with limited portions of faces? An experiment in ideal conditions

Personal identification of faces represents a challenging issue, especially for what concerns the quantification of the comparison. The 3D‐3D superimposition approach proved to distinguish between matches and mismatches. However, the potential of this procedure applied to cases where only parts of faces are visible still has to be verified. This study aimed at verifying the applicability of a 3D‐3D procedure to faces divided into three thirds. 3D models of fifty male subjects acquired through stereophotogrammetry were used. The 3D facial models were divided into upper, middle, and lower thirds and registered onto other models belonging to the same and different individuals according to the least point‐to‐point distance. In total, 50 matches and 50 mismatches were analyzed. RMS value (root mean square) of point‐to‐point distance between the two facial surfaces was calculated through VAM® software. Statistically significant differences between matches and mismatches in each facial third were assessed through Mann–Whitney test (p < 0.05). On average, RMS value in matches was 0.32 ± 0.12 mm in upper third, 0.36 ± 0.15 mm in middle third, and 0.40 ± 0.20 mm in lower third, respectively; in mismatches, RMS value was 1.40 ± 0.32 mm in upper third, 1.96 ± 0.58 mm in middle third, and 2.39 ± 0.90 mm in lower third, respectively. Differences in RMS values between matches and mismatches were significantly different for all facial thirds, without superimpositions (p < 0.01). This study shows that the existing 3D‐3D superimposition methods may be useful also when only a limited portion of face is visible in ideal conditions. Their application to forensic cases of identification still needs to be verified.

Investigating the Reliability of Novel Nasal Anthropometry Using Advanced Three-Dimensional Digital Stereophotogrammetry

Three-dimensional surface imaging systems (3DSI) provide an effective and applicable approach for the quantification of facial morphology. Several researchers have implemented 3D techniques for nasal anthropometry; however, they only included limited classic nasal facial landmarks and parameters. In our clinical routines, we have identified a considerable number of novel facial landmarks and nasal anthropometric parameters, which could be of great benefit to personalized rhinoplasty. Our aim is to verify their reliability, thus laying the foundation for the comprehensive application of 3DSI in personalized rhinoplasty. We determined 46 facial landmarks and 57 anthropometric parameters. A total of 110 volunteers were recruited, and the intra-assessor, inter-assessor, and intra-method reliability of nasal anthropometry were assessed through 3DSI. Our results displayed the high intra-assessor reliability of MAD (0.012-0.29, 0.003-0.758 mm), REM (0.008-1.958%), TEM (0-0.06), rTEM (0.001-0.155%), and ICC (0.77-0.995); inter-assessor reliability of 0.216-1.476, 0.003-2.013 mm; 0.01-7.552%, 0-0.161, and 0.001-1.481%, 0.732-0.985, respectively; and intra-method reliability of 0.006-0.598°, 0-0.379 mm; 0 0.984%, 0-0.047, and 0-0.078%, 0.996-0.998, respectively. This study provides conclusive evidence for the high reliability of novel facial landmarks and anthropometric parameters for comprehensive nasal measurements using the 3DSI system. Considering this, the proposed landmarks and parameters could be widely used for digital planning and evaluation in personalized rhinoplasty, otorhinolaryngology, and oral and maxillofacial surgery.

Morphologic reproducibility in 6 regions of the 3-dimensional facial models acquired by a standardized procedure: An in vivo study

INTRODUCTION

A standardized procedure was proposed to control involuntary motion and other factors during the capture of structural light scanning that could influence the morphology of 3-dimensional facial models; interoperator reproducibility was evaluated.

METHODS

Twenty subjects volunteered for facial scanning. Three researchers scanned each volunteer 3 times on the same day using the FaceScan structural light scanning system (Isravision, Darmstadt, Germany) and after the proposed procedure. Captures were done at 5-minute intervals. The 3 facial scans acquired by the same researcher were compared by reverse engineering software (Geomagic; 3D Systems, Rock Hill, SC). Six facial regions, including forehead, nose, paranasal, upper lip, lower lip and chin, and cheek, were divided. With the first scan as a reference, the other 2 scans were registered, and surface-to-surface distance maps were acquired to calculate the mean, standard deviation, and root mean squares (RMS) between 2 surfaces. The reproducibility between 3 researchers was then evaluated by a 1-way analysis of variance.

RESULTS

The mean of 6 facial regions was close to 0. The RMS of lip regions were largest (0.48-0.53 mm), the forehead was smallest (0.21 mm), and the others ranged 0.37 mm to 0.42 mm. The standard deviation was slightly smaller than RMS and had the same trend of change. There was no significant difference in RMS among the 3 researchers (P >0.05).

CONCLUSIONS

With the constraint of the standardized procedure, the morphologic reproducibility of facial models in 6 regions was satisfying.

Standardized Three-Dimensional Lateral Distraction Test: Its Reliability to Assess Medial Canthal Tendon Laxity

Background

Assessment of MCT laxity is critical to the surgery options. Our study aimed to analyze the reliability of measuring medial canthal tendon (MCT) laxity by using a novel standardized three-dimensional lateral distraction test (3D-LDT).

Methods

Forty-eight Caucasian volunteers (25 males and 23 females, 96 eyes) between 22 and 84 years of age (55.6 ± 18.6 years old) were included in our study. From a neutral position, the lower eyelid was gently pulled laterally along a horizontal line to define the most distracted position of the lower punctum. Both in the neutral and distracted position, standardized 3D images were acquired for each subject by two observers, and each image were measured twice by two raters. Four landmarks and six corresponding linear measurements were evaluated for intra-rater, inter-rater, and inter-method reliability.

Results

Intra-rater, inter-rater and inter-method reliability analyses of 3D-LDT revealed an intraclass correlation of more than 95%, a mean absolute difference of less than 1 mm, and a technical error of measurement of less than 1 mm. Measurements of relative error (2.59–12.04%) and relative technical error (1.83–16.05%) for the inter-landmarks distance from pupil center to the lower punctum were higher than those from limbus nasal center to the lower punctum (6.13–30.39 and 4.34–26.85%, respectively).

Conclusions

This study provided high reliability of the three-dimensional lateral distraction test (3D-LDT) for assessing medial canthal tendon (MCT) laxity, which were never evaluated by digital imaging system.

Level of Evidence IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Current and Future Photography Techniques in Aesthetic Surgery

Background

The rapidly increasing modalities and mediums of clinical photography, use of 3-dimensional (3D) and 4-dimensional (4D) patient modeling, and widening implementation of cloud-based storage and artificial intelligence (AI) call for an overview of various methods currently in use as well as future considerations in the field.

Objectives

Through a close look at the methods used in aesthetic surgery photography, clinicians will be able to select the modality best suited to their practice and goals.

Methods

Review and discussion of current data pertaining to: 2-dimensional (2D) and 3D clinical photography, current photography software, augmented reality reconstruction, AI photography, and cloud-based storage.

Results

Important considerations for current image capture include a device with a gridded viewing screen and high megapixel resolution, a tripod with leveling base, studio lighting with dual-sourced light, standardized matte finish background, and consistency in patient orientation. Currently, 3D and 4D photography devices offer advantages such as improved communication to the patient on outcome expectation and better quality of patient service and safety. AI may contribute to post-capture processing and 3D printing of postoperative outcomes. Current smartphones distort patient perceptions about their appearance and should be used cautiously in an aesthetic surgery setting. Cloud-based storage provides flexibility, cost, and ease of service while remaining vulnerable to data breaches.

Conclusions

While there are advancements to be made in the physical equipment and preparation for the photograph, the future of clinical photography will be heavily influenced by innovations in software and 3D and 4D modeling of outcomes.

Vectra 3D Simulation in Lower Eyelid Blepharoplasty: How Accurate is it?

BACKGROUND

Estimating the volume of fat to be resected during lower lid blepharoplasty can be challenging. While the excess fat is clearly visible in the upright position, it retracts into the orbital cavity when the patient is in decubitus. Several tools have been developed to predict the volume required for adequate outcomes and to reduce the risk of complications. Among these, 3D photography, in addition to being noninvasive, radiation-free, portable and relatively inexpensive, can be used to make simulations.

OBJECTIVE

To assess the level of agreement between Vectra H1 camera simulations and the outcome of lower eyelid blepharoplasties with volume removal based on these simulations.

METHODS

Preoperatively, a 3D camera and simulation software (Vectra H1, Canfield Imaging Systems) was used to estimate the fat pad volume to be resected from the lower eyelids in a sample of 35 patients (female n = 34) aged 55 years on average. Following the procedure, the patients were photographed at 1, 3 and 6 months and the outcome was compared to the simulation.

RESULTS

The agreement between the simulated volume and the intraoperative volume was high. While the difference between the postoperative volume and the simulated volume decreased over time, at 6 months the actual volume was still 0.30 mL (right eye) and 0.24 mL (left eye) larger than the simulated volume.

CONCLUSIONS

A systematic and significant difference was found between the simulation volume and the postoperative volume. The low level of agreement observed suggests that the accuracy of the tested software is insufficient for reliable simulations.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Chairside virtual patient protocol. Part 1: Free vs Guided face scan protocol

OBJECTIVES

The 3D facial scan technology allows to virtualize the face of the patient, that can be incorporated with other 3D dental images produced by digital scanning of the dental structures. Aim of this study is to investigate the trueness and precision of a low-cost portable face scanner, with two different scan techniques MATERIALS AND METHODS: Ten patients were enrolled for this study and seventeen soft tissue landmarks were selected to perform linear facial measurements, specifically Reference (Ref), Pronasion (Prn), Subnasal (Sn), Exocanthion Left (Ex-L), Exocanthion Right (Ex-R), Pogonion (Pg), Glabella (G), Alar curvature Right (Al-R), Alar curvature Left (Al-L), Zygion Left (Zn-L), Zygion Right (Zn-R), Orbital Left (Or-L), Orbital Right (Or-R), Tragus Right (T-R), Tragus Left (T-L), Chelion Right (Ch-R) and Chelion Left (Ch-L). Interlandmark distances were measured both manually and digitally. For the manual group ten measurements were made using a digital caliper. For digital group measurements were recorded on the patient face scan obtained using an Ipad Pro 3rd Gen. (Apple Store, Cupertino, CA, USA) and Bellus3D Dental Pro-App (Bellus3D, Inc. Campbell, CA, USA) using "face mode" scan with two different scanning techniques, named Free technique (FT) and Slider Technique (ST). Ten measurements were made for each technique. An open-source software (Meshlab; Meshlab) was used to record all the distances. A paired t-test was used to analyze FT and ST results. In order to further evaluate precision and scan repeatability a surface analysis was performed with both scanning techniques using a CAD software (GOM inspect, GOM) and the total differences in absolute 3D deviations were calculated as root mean square.

RESULTS

The comparison between manual and digital measurements showed a mean absolute difference of 0.95±0.25 for FT and 1.00±0.29 for the ST. Trueness analysis showed statistically significant differences for the Exocanthion L- Exocanthion R measurement with FT having better performance (P<.05). Precision analysis showed statistically significant differences for G-Pg, Ref-Zn-R and Prn-Zn-R with ST having better performance (P<.05). To achieve all the scans required without any signs of deformation, 184 scans were performed using Free technique and 124 scans using Slider technique. Surface analysis revealed a mean distance of 0.12±0.45 between Free scans and 0.13±0.46 between Slider scans in accordance with the linear measurement analysis CONCLUSION: The study showed that accuracy of low-cost portable scanner can be suitable for clinical use. The use of ST is suggested for a reliable clinical use due to the better precision and an effective reduction of motion artifacts and the lower compliance required to the patients during the scan.

Influence of Marker Number and Position on Accuracy of Breast Measurement With Three-Dimensional Camera

BACKGROUND

The VECTRA H1 three-dimensional (3D) imaging system (Canfield Scientific, Parsippany, NJ) enables easy 3D image construction and measurement. Although the number and positions of markers on the skin for image synthesis might affect accuracy of measurements, few studies have mentioned the possibility. This study investigated the accuracy and reproducibility of distance measurements using VECTRA H1, focusing on the number and positions of markers.

METHODS

A total of 3, 5, or 7 markers were attached to a female breast model including lateral markers 6 cm from the midline and photographed with VECTRA. Five markers were configured in more two ways, with the lateral markers either positioned 3 cm outside the midline (narrow interval) or 9 cm outside the midline (wide interval). 3D models were created three times under each condition, for a total of 15 models. Differences (measurement error) between measured values on 3D models and actual measured values were verified for six distances, such as distance between the nipples.

RESULTS

The average difference was 11.1 mm with 3 markers (95% confidence interval (CI), 4.38-17.7 mm, p = 0.0028). In comparison, average difference was -0.395 mm (-0.866 to 0.0763 mm, p = 0.095) with 5 markers, and 0.139 mm (-0186 to 0.465 mm, p = 0.379) with 7 markers, all less than 1 mm. Average difference with narrow interval 5 markers was larger than one with wide interval.

CONCLUSIONS

In 3D imaging of the breast using VECTRA H1, distance measurements offering clinically satisfactory accuracy can be made by setting appropriate marker conditions.

LEVEL OF EVIDENCE V

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Facial and Eyelid Changes in Thyroid Eye Disease Are Reversed by Teprotumumab

Thyroid eye disease (TED) causes orbital soft-tissue expansion. Recent studies have suggested that brow and temple changes may also occur. Teprotumumab, a monoclonal antibody to the insulin-like growth factor 1 receptor reduces soft-tissue swelling in TED. In this study, we quantified the changes to pan facial soft-tissue volumes and eyelid position, following treatment with teprotumumab.