Accuracy of 3-dimensional stereophotogrammetry: Comparison of the 3dMD and Bellus3D facial scanning systems with one another and with direct anthropometry

RationaleDelivery of continuous positive airway pressure (CPAP) is the standard treatment for obstructive sleep apnea (OSA) in children and adults. Treatment adherence is a major challenge as many patients find the CPAP mask uncomfortable. The study aim was to demonstrate the feasibility of delivered CPAP through customised nasal masks by assessing mask leak and comfort of customised masks compared to commercially available CPAP masks.MethodsSix healthy adult volunteers participated in a cross-over study including commercial masks in three different sizes (petite, small/medium, and large) from the same supplier and a customised mask fabricated for each subject using 3D facial scanning and modern additive manufacturing processes. Mask leak and comfort were assessed with varying CPAP levels and mask tightness. Leak was measured in real time using an inline low-resistance Pitot tube flow sensor, and each mask was ranked for comfort by the subjects.ResultsMask leak rates varied directly with CPAP level and inversely with mask tightness. When ranked for comfort, three subjects favoured the customised mask while three favoured a commercial mask. The petite mask yielded the highest mask leaks and was ranked least comfortable by all subjects. Relative mask leaks and comfort rankings for the other commercial and customised masks varied between individuals. Mask leak was comparable when comparing the customised masks with the highest ranked commercial masks.ConclusionCustomised masks successfully delivered target CPAP settings in all six subjects, demonstrating the feasibility of this approach.

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A New Frame for Orienting Infants With Cleft Lip and Palate During 3-Dimensional Facial Scanning

The Cleft Palate-Craniofacial Journal ◽

10.1177/10556656211028512 ◽

2021 ◽

pp. 105566562110285

Author(s):

KH Alisha ◽

Puneet Batra ◽

Sreevatsan Raghavan ◽

Karan Sharma ◽

Aditya Talwar

Keyword(s):

Cleft Lip ◽

Cleft Lip And Palate ◽

3 Dimensional ◽

Whole Process ◽

The Face ◽

Ideal Tool ◽

Considerable Distortion ◽

The One ◽

Camera Holder ◽

Facial Scanning

Background: Nonradiographic 3-D assessment of soft tissue facial structures is an ideal tool to measure 3-D facial change and smartphone apps like Bellus 3D have brought these technologies to our doorsteps. Although this app works well for adults, it doesn’t do so well with infants as their stabilization is difficult thus proper alignment becomes problematic often leading to distortion. This seriously hampers the repeatability and reliability of the whole process. Material and Method: A stainless steel rod of 150-cm length is curved into a semicircle of a radius of 42.5 cm. Bases are fabricated at both the ends to firmly hold the stand on the table. A Teflon ring of one inch is made for adjusting the diameter of the camera holder. A camera holder is then attached to the Teflon ring. The mobile holder mounted is free to move within the arc. A 3-D facial scan of a single patient was carried out with the camera mounted on the frame and once without the frame. The same was compared using side-by-side comparison and superimposition of the .STL files from the frontal, profile, and worm’s eye view. Result and Conclusion: It was found that considerable distortion was noted around the nasal and paranasal areas when the scan was performed without the frame as compared to the one that was taken with the frame. This technique avoided distortion and the difficulty in turning the baby’s head to record the lateral portion of the face.

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Accuracy of Mobile Device–Compatible 3D Scanners for Facial Digitization: Systematic Review and Meta-Analysis (Preprint)

10.2196/preprints.22228 ◽

2020 ◽

Author(s):

Hang-Nga Mai ◽

Du-Hyeong Lee

Keyword(s):

Mobile Device ◽

Meta Analysis ◽

Cochrane Library ◽

Data Sets ◽

Craniomaxillofacial Surgery ◽

3D Scanners ◽

The Difference ◽

Facial Scanning ◽

Anatomical Information ◽

Scanning Systems

BACKGROUND The accurate assessment and acquisition of facial anatomical information significantly contributes to enhancing the reliability of treatments in dental and medical fields, and has applications in fields such as craniomaxillofacial surgery, orthodontics, prosthodontics, orthopedics, and forensic medicine. Mobile device–compatible 3D facial scanners have been reported to be an effective tool for clinical use, but the accuracy of digital facial impressions obtained with the scanners has not been explored. OBJECTIVE We aimed to review comparisons of the accuracy of mobile device–compatible face scanners for facial digitization with that of systems for professional 3D facial scanning. METHODS Individual search strategies were employed in PubMed (MEDLINE), Scopus, Science Direct, and Cochrane Library databases to search for articles published up to May 27, 2020. Peer-reviewed journal articles evaluating the accuracy of 3D facial models generated by mobile device–compatible face scanners were included. Cohen d effect size estimates and confidence intervals of standardized mean difference (SMD) data sets were used for meta-analysis. RESULTS By automatic database searching, 3942 articles were identified, of which 11 articles were considered eligible for narrative review, with 6 studies included in the meta-analysis. Overall, the accuracy of face models obtained using mobile device–compatible face scanners was significantly lower than that of face models obtained using professional 3D facial scanners (SMD 3.96 mm, 95% CI 2.81-5.10 mm; z=6.78; <i>P</i><.001). The difference between face scanning when performed on inanimate facial models was significantly higher (SMD 10.53 mm, 95% CI 6.29-14.77 mm) than that when performed on living participants (SMD 2.58 mm, 95% CI 1.70-3.47 mm, <i>P</i><.001, df=12.94). CONCLUSIONS Overall, mobile device–compatible face scanners did not perform as well as professional scanning systems in 3D facial acquisition, but the deviations were within the clinically acceptable range of <1.5 mm. Significant differences between results when 3D facial scans were performed on inanimate facial objects and when performed on the faces of living participants were found; thus, caution should be exercised when interpreting results from studies conducted on inanimate objects.

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Intersections of Epigenetics, Twinning and Developmental Asymmetries: Insights Into Monogenic and Complex Diseases and a Role for 3D Facial Analysis

Twin Research and Human Genetics ◽

10.1375/twin.14.4.305 ◽

2011 ◽

Vol 14 (4) ◽

pp. 305-315 ◽

Cited By ~ 11

Author(s):

Gareth Baynam ◽

Peter Claes ◽

Jeffrey M. Craig ◽

Jack Goldblatt ◽

Stefanie Kung ◽

...

Keyword(s):

Geometric Morphometrics ◽

Emerging Technologies ◽

Complex Diseases ◽

Developmental Processes ◽

Facial Analysis ◽

3 Dimensional ◽

Body Patterning ◽

Measures Of Asymmetry ◽

Facial Scanning ◽

Early Developmental

For decades the relationships of twinning and alterations in body patterning, such as laterality and asymmetry, have been investigated. However, the tools to define and quantify these relationships have been limited and the majority of these studies have relied on associations with subjectively defined phenotypes. The emerging technologies of 3-dimensional (3D) facial scanning and geometric morphometrics are providing the means to establish objective criteria, including measures of asymmetry, which can be used for phenotypic classification and investigations. Additionally, advances in molecular epigenetics provide new opportunities for novel investigations of mechanisms central to early developmental processes, twinning and related phenotypes. We review the evidence for overlapping etiologies of twinning, asymmetry and selected monogenic and complex diseases, and we suggest that the combination of epigenetic investigations with detailed and objective phenotyping, utilizing 3D facial analysis tools, can reveal insights into the genesis of these phenomena.

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Accuracy of Mobile Device–Compatible 3D Scanners for Facial Digitization: Systematic Review and Meta-Analysis

Journal of Medical Internet Research ◽

10.2196/22228 ◽

2020 ◽

Vol 22 (10) ◽

pp. e22228 ◽

Cited By ~ 1

Author(s):

Hang-Nga Mai ◽

Du-Hyeong Lee

Keyword(s):

Mobile Device ◽

Meta Analysis ◽

Cochrane Library ◽

Data Sets ◽

Craniomaxillofacial Surgery ◽

3D Scanners ◽

The Difference ◽

Facial Scanning ◽

Anatomical Information ◽

Scanning Systems

Background The accurate assessment and acquisition of facial anatomical information significantly contributes to enhancing the reliability of treatments in dental and medical fields, and has applications in fields such as craniomaxillofacial surgery, orthodontics, prosthodontics, orthopedics, and forensic medicine. Mobile device–compatible 3D facial scanners have been reported to be an effective tool for clinical use, but the accuracy of digital facial impressions obtained with the scanners has not been explored. Objective We aimed to review comparisons of the accuracy of mobile device–compatible face scanners for facial digitization with that of systems for professional 3D facial scanning. Methods Individual search strategies were employed in PubMed (MEDLINE), Scopus, Science Direct, and Cochrane Library databases to search for articles published up to May 27, 2020. Peer-reviewed journal articles evaluating the accuracy of 3D facial models generated by mobile device–compatible face scanners were included. Cohen d effect size estimates and confidence intervals of standardized mean difference (SMD) data sets were used for meta-analysis. Results By automatic database searching, 3942 articles were identified, of which 11 articles were considered eligible for narrative review, with 6 studies included in the meta-analysis. Overall, the accuracy of face models obtained using mobile device–compatible face scanners was significantly lower than that of face models obtained using professional 3D facial scanners (SMD 3.96 mm, 95% CI 2.81-5.10 mm; z=6.78; P<.001). The difference between face scanning when performed on inanimate facial models was significantly higher (SMD 10.53 mm, 95% CI 6.29-14.77 mm) than that when performed on living participants (SMD 2.58 mm, 95% CI 1.70-3.47 mm, P<.001, df=12.94). Conclusions Overall, mobile device–compatible face scanners did not perform as well as professional scanning systems in 3D facial acquisition, but the deviations were within the clinically acceptable range of <1.5 mm. Significant differences between results when 3D facial scans were performed on inanimate facial objects and when performed on the faces of living participants were found; thus, caution should be exercised when interpreting results from studies conducted on inanimate objects.

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Coastal Monitoring: A New Approach

Chimera ◽

10.33178/chimera.26.9 ◽

2013 ◽

Vol 26 (2012/2013) ◽

pp. 69-83

Author(s):

Sarah M. Kandrot

Keyword(s):

Laser Scanning ◽

Morphological Changes ◽

Survey Methods ◽

Terrestrial Laser Scanning ◽

Coastal Environments ◽

3 Dimensional ◽

Multi Temporal ◽

Hazard And Risk ◽

Maximum Protection ◽

Scanning Systems

Monitoring changes in the morphology of coastal environments is important for understanding how they function as systems and how they can be most effectively managed to offer maximum protection of the coastal hinterland. The quick, precise, and efficient method of topographic data capture associated with a remote sensing (RS) technology called terrestrial laser scanning (TLS), also known as ground-based Light Detection and Ranging (LiDAR), facilitates improved monitoring of morphological changes to coastal environments over traditional survey methods. Terrestrial laser scanning systems are capable of providing extremely detailed 3-dimensional topographic information in the form of a “point cloud” – a densely packed collection of x,y,z coordinates that collectively represent the external surface (often the ground) of a surveyed area. Such detailed elevation information is useful for coastal research, resource management and planning, hazard and risk assessment, and evaluating the impacts of climate change and sea-level rise on the coast. This paper introduces TLS and its applications in a coastal setting and addresses some of the challenges associated with its use as a monitoring tool in vegetated coastal dune environments. Such challenges include optimising time spent in the field, working with large datasets, classifying simple and complex scenes, and analysing multi-temporal datasets.

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Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080249 ◽

1977 ◽

Vol 35 ◽

pp. 562-563

Author(s):

Robert Glaeser ◽

Thomas Bauer ◽

David Grano

Keyword(s):

Three Dimensional ◽

Dimensional Structure ◽

Serial Sections ◽

Thin Sections ◽

3 Dimensional ◽

Transmission Electron ◽

Freeze Dried ◽

Dimensional Reconstruction ◽

Stereo Imagery ◽

Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

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Structural preservation and absolute contrast of catalase crystal sections prepared with tannic acid

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010007597x ◽

1983 ◽

Vol 41 ◽

pp. 448-449

Author(s):

C.W. Akey ◽

M. Szalay ◽

S.J. Edelstein

Keyword(s):

Tannic Acid ◽

Beef Heart ◽

X Rays ◽

Screw Axis ◽

General Applicability ◽

Thin Sections ◽

Beef Liver ◽

3 Dimensional ◽

Dimensional Reconstruction ◽

Structural Preservation

Three methods of obtaining 20 Å resolution in sectioned protein crystals have recently been described. They include tannic acid fixation, low temperature embedding and grid sectioning. To be useful for 3-dimensional reconstruction thin sections must possess suitable resolution, structural fidelity and a known contrast. Tannic acid fixation appears to satisfy the above criteria based on studies of crystals of Pseudomonas cytochrome oxidase, orthorhombic beef liver catalase and beef heart F1-ATPase. In order to develop methods with general applicability, we have concentrated our efforts on a trigonal modification of catalase which routinely demonstrated a resolution of 40 Å. The catalase system is particularly useful since a comparison with the structure recently solved with x-rays will permit evaluation of the accuracy of 3-D reconstructions of sectioned crystals.Initially, we re-evaluated the packing of trigonal catalase crystals studied by Longley. Images of the (001) plane are of particular interest since they give a projection down the 31-screw axis in space group P3121. Images obtained by the method of Longley or by tannic acid fixation are negatively contrasted since control experiments with orthorhombic catalase plates yield negatively stained specimens with conditions used for the larger trigonal crystals.

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Deviations from Ideal Decagonal Symmetry in Electron Diffraction Patterns of the “Decagonal” Phase in the Al-Co-Cu Alloy System

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088889 ◽

1991 ◽

Vol 49 ◽

pp. 914-915

Author(s):

Atul S. Ramani ◽

Earle R. Ryba ◽

Paul R. Howell

Keyword(s):

Electron Microscope ◽

Alloy System ◽

Nominal Composition ◽

Dimensional Lattice ◽

3 Dimensional ◽

Decagonal Phase ◽

Cu Alloy ◽

Transmission Electron ◽

Lattice Periodicity ◽

Diffraction Patterns

The “decagonal” phase in the Al-Co-Cu system of nominal composition Al65CO15Cu20 first discovered by He et al. is especially suitable as a topic of investigation since it has been claimed that it is thermodynamically stable and is reported to be periodic in the dimension perpendicular to the plane of quasiperiodic 10-fold symmetry. It can thus be expected that it is an important link between fully periodic and fully quasiperiodic phases. In the present paper, we report important findings of our transmission electron microscope (TEM) study that concern deviations from ideal decagonal symmetry of selected area diffraction patterns (SADPs) obtained from several “decagonal” phase crystals and also observation of a lattice of main reflections on the 10-fold and 2-fold SADPs that implies complete 3-dimensional lattice periodicity and the fundamentally incommensurate nature of the “decagonal” phase. We also present diffraction evidence for a new transition phase that can be classified as being one-dimensionally quasiperiodic if the lattice of main reflections is ignored.

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