3D analysis of facial morphology

3D Head Shape Feature Analysis of Zika-Infected Children

Congenital Zika syndrome (CZS) has been identified a constellation of congenital anomalies caused by Zika Virus (ZKV) infection during pregnancy. The infection with ZKV could lead to microcephaly of the fetus due to a severe decrease in brain volume and reduced brain growth. The preliminary screening of CZS is based on measuring head circumference; the diagnosis is made if this measurement is below two standard deviations below the mean. The analyses of the 3D head features of infected infants are limited. This study analyzed 3D head images of 35 ZKV-positive cases with an average age of 16.8 ± 2 months and 35 controls with an average age of 14.4 ± 5 months. This study focused on identifying potential diagnostic characteristics of CZS. The 3D head images were captured using a 3D imaging system. The averaged images of the two groups were aligned to illustrate the size and shape differences. There were significant differences in centroid size, head circumference (HC), head height (HH), and chin height (CH) between the two groups. We also identified significant differences in the indices of chin height/total facial height (CH/TFH) and head height/head circumference ratio (HH/HC) between the CZS and control cases. An HH/HC of 0.49 showed a sensitivity of 0.86 and a specificity of 0.74 in diagnosing CZS, which is more sensitive than the routinely used HC measurement. The index of HH/HC has potential to be used as the gold standard for the early screening for the detection of CZS cases.

Proton beam therapy and dentofacial development in paediatric cancer patients: A scoping review

Purpose

It is known that radiation to dentofacial structures during childhood can lead to developmental disturbances. However, this appears to be a relatively subordinated research subject. For this reason, this review aims to establish the current evidence base on the effect of PBT on dentofacial development in paediatric patients treated for cancer in the head and neck region.

Materials and methods

A comprehensive search was undertaken to identify both published and unpublished studies or reports. A single reviewer completed initial screening of abstracts; 2 independent reviewers completed secondary screening and data extraction. A narrative synthesis was then conducted.

Results

82 records were screened in total, resulting in 11 included articles. These articles varied in terms of study design and reporting quality. Owing to both poor study reporting and limited patient numbers, it is not possible to determine the effect of cancer diagnosis, chronological age at treatment, radiation dose or treatment modality on the incidence of facial deformation or dental development anomalies.

Conclusion

Disturbances in dentofacial development are an under-reported toxicity in paediatric cancer survivors treated with PBT to the head and neck. There is a need for more research on dentofacial toxicity reporting, focused on the impact of treatment age, radiation dose, concurrent therapies, and the subsequent impact on quality of life.

Average Three-Dimensional Skeletofacial Model as a Template for Bone Repositioning during Virtual Orthognathic Surgery

BACKGROUND

Virtual planning has revolutionized orthognathic surgery. This study presents a computer-assisted method for constructing average three-dimensional skeletofacial models that can be applied as templates for surgical planning for maxillomandibular repositioning.

METHODS

The authors used the images of 60 individuals (30 women and 30 men) who had never undergone orthognathic surgery to construct an average three-dimensional skeletofacial model for male participants and one for female participants. The authors validated the accuracy of the newly developed skeletofacial models by comparing their images with 30 surgical simulation images (ie, skulls) that had been created using three-dimensional cephalometric normative data. The comparison was conducted by superimposing surgical simulation images created using the authors' models with the previously created images to analyze their differences, particularly differences in the jawbone position.

RESULTS

For all participants, the authors compared the jaw position in the surgical simulation images created using the authors' average three-dimensional skeletofacial models with that in the images created using three-dimensional cephalometric normative data. The results revealed that the planned maxillary and mandibular positions were similar in both images and that the differences between all facial landmarks were less than 1 mm, except for one dental position. Most studies have reported less than 2 mm to be the success criterion for the distance difference between planned and outcome images; thus, the authors' data indicate high consistency between the images in terms of jawbone position.

CONCLUSION

The authors' average three-dimensional skeletofacial models provide an innovative template-assisted orthognathic surgery planning modality that can enhance the fully digital workflow for virtual orthognathic surgical planning.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

An interactive atlas of three-dimensional syndromic facial morphology

Craniofacial phenotyping is critical for both syndrome delineation and diagnosis because craniofacial abnormalities occur in 30% of characterized genetic syndromes. Clinical reports, textbooks, and available software tools typically provide two-dimensional, static images and illustrations of the characteristic phenotypes of genetic syndromes. In this work, we provide an interactive web application that provides three-dimensional, dynamic visualizations for the characteristic craniofacial effects of 95 syndromes. Users can visualize syndrome facial appearance estimates quantified from data and easily compare craniofacial phenotypes of different syndromes. Our application also provides a map of morphological similarity between a target syndrome and other syndromes. Finally, users can upload 3D facial scans of individuals and compare them to our syndrome atlas estimates. In summary, we provide an interactive reference for the craniofacial phenotypes of syndromes that allows for precise, individual-specific comparisons of dysmorphology.

Population-specific facial traits and diagnosis accuracy of genetic and rare diseases in an admixed Colombian population

Up to 40% of rare disorders (RD) present facial dysmorphologies, and visual assessment is commonly used for clinical diagnosis. Quantitative approaches are more objective, but mostly rely on European descent populations, disregarding diverse population ancestry. Here, we assessed the facial phenotypes of Down (DS), Morquio (MS), Noonan (NS) and Neurofibromatosis type 1 (NF1) syndromes in a Latino-American population, recording the coordinates of 18 landmarks in 2D images from 79 controls and 51 patients. We quantified facial differences using Euclidean Distance Matrix Analysis, and assessed the diagnostic accuracy of Face2Gene, an automatic deep-learning algorithm. Individuals diagnosed with DS and MS presented severe phenotypes, with 58.2% and 65.4% of significantly different facial traits. The phenotype was milder in NS (47.7%) and non-significant in NF1 (11.4%). Each syndrome presented a characteristic dysmorphology pattern, supporting the diagnostic potential of facial biomarkers. However, population-specific traits were detected in the Colombian population. Diagnostic accuracy was 100% in DS, moderate in NS (66.7%) but lower in comparison to a European population (100%), and below 10% in MS and NF1. Moreover, admixed individuals showed lower facial gestalt similarities. Our results underscore that incorporating populations with Amerindian, African and European ancestry is crucial to improve diagnostic methods of rare disorders.

Parents' perspectives on the use of children's facial images for research and diagnosis: a survey

Computer-aided facial diagnostic tools are valuable emerging technologies for the early detection and initial diagnosis of congenital disorders. These tools require large datasets of facial photographs, especially of infants and children, to identify these disorders and improve classification accuracies. Researchers need to balance this need for larger datasets with patients' privacy rights, needs and preferences. This study aimed to investigate parents' views regarding the collection, storage, use and publication of their children's facial images for research and diagnostic purposes. A total of 151 parents of children with and without congenital disorders completed an online survey evaluating their views on the collection, storage, use and publication of children's facial images for research and diagnosis. Overall, 72.5% of parents would allow researchers to take facial photographs of their children, preferring the images to be stored in a secure database that is not available to the public. Parents of children with congenital disorders were more accepting of researchers taking facial photographs of their children, compared to parents of children without these conditions. Half of the respondents would allow facial photographs of their children to be published in academic journals, without their eyes covered, and this acceptance increased as the proportion of the child's face covered increased. Parents also indicated specific requirements to allow the use of these images in other similar research studies which need to be taken into consideration when planning studies that involve facial analysis research.

A study on segmentation and refinement of key human body parts by integrating manual measurements

Optimal ergonomic design for consumer goods (such as garments and furniture) cannot be perfectly realised because of imprecise interactions between products and human models. In this paper, we propose a new body classification method that integrates human skeleton features, expert experience, manual measurement methods, and statistical analysis (principal component analysis and K-means clustering). Taking the upper body of young males as an example, the proposed method enables the classification of upper bodies into a number of levels at three key body segments (the arm root [seven levels], the shoulder [five levels], and the torso [below the shoulder, eight levels]). From several experiments, we found that the proposed method can lead to more accurate results than the classical classification methods based on three-dimensional (3 D) human model and can provide semantic knowledge of human body shapes. This includes interpretations of the classification results at these three body segments and key feature point positions, as determined by skeleton features and expert experience. Quantitative analysis also demonstrates that the reconstruction errors satisfy the requirements of garment design and production. Practitioner summary The acquisition and classification of anthropometric data constitute the basis of ergonomic design. This paper presents a new method for body classification that leads to more accurate results than classical classification methods (which are based on human body models). We also provide semantic knowledge about the shape of human body. The proposed method can also be extended to 3 D body modelling and to the design of other consumer products, such as furniture, seats, and cars. Abbreviations: PCA: principal component analysis; KMO: Kaiser-Meyer-Olkin; ANOVA: analysis of variance; 3D: three-dimensional; 2D: two-dimensional; ISO: International Standardisation Organisation; BFB: body-feature-based.

Multidisciplinary interaction and MCD gene discovery. The perspective of the clinical geneticist

The increasing pace of gene discovery in the last decade has brought a major change in the way the genetic causes of brain malformations are being diagnosed. Unbiased genomic screening has gained the first place in the diagnostic protocol of a child with congenital (brain) anomalies and the detected variants are matched with the phenotypic presentation afterwards. This process is defined as "reverse phenotyping". Screening of DNA, through copy number variant analysis of microarrays and analysis of exome data on different platforms, obtained from the index patient and both parents has become a routine approach in many centers worldwide. Clinicians are used to multidisciplinary team interaction in patient care and disease management and this explains why the majority of research that has led to the discovery of new genetic disorders nowadays proceeds from clinical observations to genomic analysis and to data exchange facilitated by open access sharing databases. However, the relevance of multidisciplinary team interaction has not been object of systematic research in the field of brain malformations. This review will illustrate some examples of how diagnostically driven questions through multidisciplinary interaction, among clinical and preclinical disciplines, can be successful in the discovery of new genes related to brain malformations. The first example illustrates the setting of interaction among neurologists, geneticists and neuro-radiologists. The second illustrates the importance of interaction among clinical dysmorphologists for pattern recognition of syndromes with multiple congenital anomalies. The third example shows how fruitful it can be to step out of the "clinical comfort zone", and interact with basic scientists in applying emerging technologies to solve the diagnostic puzzles.

Age- and Sex-Related Changes in Labial Dimensions of Sudanese Youngs of Arab Descent: A Three-Dimensional Cross-Sectional Study

Proper evaluation of facial features during growth and development requires the knowledge of anthropometric reference values validated for ethnicity, sex and age. In order to provide information concerning the normal sex-related size of the lips during childhood and young adulthood in Sudanese people of Arab descent, the three-dimensional coordinates of nine labial soft tissue landmarks were obtained by a laser scanner in 332 male and 386 female healthy Northern Sudanese subjects aged 3-30 years. Six labial linear distances, the vermilion height to mouth width ratio, vermilion areas and lip volumes were calculated and averaged for age and sex. Comparisons were performed by factorial analysis of variance (p < 0.01). All labial dimensions significantly increased with age. Significant effects of sex were found for four measurements only, with very small effect size; nonetheless, lips and their parts grew faster in females than in males at almost all ages. Philtrum width was the first linear distance that attained adult values. The vermilion height to mouth width ratio was nearly constant across the age groups. Data collected in this study contribute to information about ethnic-specific lip morphology during growth and development. As orolabial features change over time with their own pattern, the relevant age-related trends should be properly considered for clinical treatment planning.

The Characterisation of the Craniofacial Morphology of Infants Born With Zika Virus; Innovative Approach for Public Health Surveillance and Broad Clinical Applications

Background: This study was carried out in response to the Zika virus epidemic, which constituted a public health emergency, and to the 2019 WHO calling for strengthened surveillance for the early detection of related microcephaly. The main aim of the study was to phenotype the craniofacial morphology of microcephaly using a novel approach and new measurements, and relate the characteristics to brain abnormalities in Zika-infected infants in Brazil to improve clinical surveillance.

Methods: 3D images of the face and the cranial vault of 44 Zika-infected infants and matched healthy controls were captured using a 3D stereophotogrammetry system. The CT scans of the brain of the infected infants were analysed. Principal component analysis (PCA) was applied to characterise the craniofacial morphology. In addition to the head circumference (HC), a new measurement, head height (HH), was introduced to measure the cranial vault. The level of brain abnormality present in the CT scans was assessed; the severity of parenchymal volume loss and ventriculomegaly was quantified. Student's t-test and Spearman's Rho statistical test have been applied.

Findings: The PCA identified a significant difference (p < 0.001) between the cranial vaults and the face of the Zika infants and that of the controls. Spearman's rank-order correlation coefficients show that the head height (HH) has a strong correlation (0.87 in Zika infants; 0.82 in controls) with the morphology of the cranial vaults, which are higher than the correlation with the routinely used head circumference (HC). Also, the head height (HH) has a moderate negative correlation (−0.48) with the brain abnormalities of parenchymal volume loss.

Interpretation: It is discovered that the head height (HH) is the most sensitive and discriminatory measure of the severity of cranial deformity, which should be used for clinical surveillance of the Zika syndrome, evaluation of other craniofacial syndromes and assessment of various treatment modalities.

Bowman A. Functional data analysis and visualisation of three-dimensional surface shape

The advent of high-resolution imaging has made data on surface shape widespread. Methods for the analysis of shape based on landmarks are well established but high-resolution data require a functional approach. The starting point is a systematic and consistent description of each surface shape and a method for creating this is described. Three innovative forms of analysis are then introduced. The first uses surface integration to address issues of registration, principal component analysis and the measurement of asymmetry, all in functional form. Computational issues are handled through discrete approximations to integrals, based in this case on appropriate surface area weighted sums. The second innovation is to focus on sub-spaces where interesting behaviour such as group differences are exhibited, rather than on individual principal components. The third innovation concerns the comparison of individual shapes with a relevant control set, where the concept of a normal range is extended to the highly multivariate setting of surface shape. This has particularly strong applications to medical contexts where the assessment of individual patients is very important. All of these ideas are developed and illustrated in the important context of human facial shape, with a strong emphasis on the effective visual communication of effects of interest.

Three-Dimensional Evaluation of the Depressor Anguli Oris and Depressor Labii Inferioris for Botulinum Toxin Injections

BACKGROUND

Botulinum toxin type A (BoNT-A) injection administered at an inappropriate site or depth can produce an unwanted change in facial animation because the depressor anguli oris (DAO) and depressor labii inferioris (DLI) muscles are partially overlapped. Therefore, simple BoNT-A injection guidelines, based on 3-dimensional (3D) facial anatomic references and landmarks, would be very useful.

OBJECTIVES

The aim of this study was to establish novel BoNT-A injection guidelines that include the soft tissue thickness at the lower perioral region. Data were acquired with a 3D scanning system combined with dissections in order to obtain accurate injection sites and depths for the DAO and DLI.

METHODS

3D scans of the facial skin, superficial fat, and facial muscle surface were performed in 45 embalmed cadavers. The thicknesses of the skin and subcutaneous layer were calculated automatically from superimposed images at each of 5 reference points (P) in the perioral region.

RESULTS

In every case (100%), P3 and P5 were located in the DLI and DAO areas, respectively (45/45). Therefore, we defined P3 as the "DLI point" and P5 as the "DAO point." The soft tissue thicknesses at the DLI and DAO points were 6.4 [1.7] mm and 6.7 [1.8] mm, respectively.

CONCLUSIONS

The P3 and P5 described in this study are effective guidelines that only target the DLI and DAO. Clinicians, specifically, can easily use facial landmarks, such as the cheilion and pupil, to assign the DLI and DAO points without any measurement or palpation of the modiolus.

Impairment in facial expression generation in patients with repaired unilateral cleft lip: Effects of the physical properties of facial soft tissues

Patients with repaired unilateral cleft lip with palate (UCLP) often show dysmorphology and distorted facial motion clinically, which can cause psychological issues. However, no report has clarified the details concerning distorted facial motion and the corresponding possible causative factors. In this study, we hypothesized that the physical properties of the scar and surrounding facial soft tissue might affect facial displacement while smiling in patients with UCLP (Cleft group). We thus examined the three-dimensional (3D) facial displacement while smiling in the Cleft and Control groups in order to determine whether or not the physical properties of facial soft tissues differ between the Cleft and Control groups and to examine the relationship between the physical properties of facial soft tissues on 3D facial displacement while smiling. Three-dimensional images at rest and while smiling as well as the facial physical properties (e.g. viscoelasticity) of both groups were recorded. Differences in terms of physical properties and facial displacement while smiling between the two groups were examined. To examine the relationship between facial surface displacement while smiling and physical properties, a canonical correlation analysis (CCA) was conducted. As a result, three typical abnormal features of smiling in the Cleft group compared with the Control group were noted: less upward and backward displacement on the scar area, downward movement of the lower lip, and a greater asymmetric displacement, including greater lateral displacement of the subalar on the cleft side while smiling and greater alar backward displacement on the non-cleft side. The Cleft group also showed greater elastic modulus at the upper lip on the cleft side, suggesting hardened soft tissue at the scar. The CCA showed that this hard scar significantly affected facial displacement, inducing less upward and backward displacement on the scar area and downward movement of the lower lip in patients with UCLP (correlation coefficient = 0.82, p = 0.04); however, there was no significant relationship between greater nasal alar lateral movement and physical properties of the skin at the scar. Based on these results, personalizing treatment options for dysfunction in facial expression generation may require quantification of the 3D facial morphology and physical properties of facial soft tissues.

Three-dimensional topography of facial soft tissues for the safer and effective threading procedures

INTRODUCTION

To reduce complications caused by the procedure, the target layer for thread lifting should be the superficial fat or superficial musculoaponeurotic system of the face. The aim of this study was to establish the thicknesses of the facial skin and superficial fat using a 3D scanning system to provide basic clinical data for thread lifting.

MATERIAL AND METHODS

Thirty fixed Korean and Thai cadavers (male: 17, female: 13) were used. The depths of the skin and superficial fat were measured using a three dimensional (3D) structured-light scanner. Facial images of both undissected and removed skin and superficial fat were taken with the 3D scanner. The paths from the temple and the front of the tragus to the infraorbital, perioral, cheek, and mental areas were displayed on the 3D image. The thickness along the path was measured by calculating the difference between the undissected and dissected 3D images.

RESULTS

The means and standard deviations of thicknesses of the skin and superficial fat were 2.1 ± 0.4 mm and 5.2 ± 1.9 mm in the 11 pathways. The facial skin became thicker going toward the lower aspect of the face from temple to infraorbtial and perioral regions. The thickness of the superficial fat around the marionette line showed the biggest change.

CONCLUSIONS

The present findings indicate that a 3D scanning system can yield crucial anatomical information about the thickness of the facial skin and superficial fat for use in various minimally invasive clinical procedures including thread lifting.

Three-dimensional facial morphology in Cantú syndrome

Cantú syndrome (CS) was first described in 1982, and is caused by pathogenic variants in ABCC9 and KCNJ8 encoding regulatory and pore forming subunits of ATP-sensitive potassium (K_ATP ) channels, respectively. It is characterized by congenital hypertrichosis, osteochondrodysplasia, extensive cardiovascular abnormalities and distinctive facial anomalies including a broad nasal bridge, long philtrum, epicanthal folds, and prominent lips. Many genetic syndromes, such as CS, involve facial anomalies that serve as a significant clue in the initial identification of the respective disorder before clinical or molecular diagnosis are undertaken. However, an overwhelming number of CS patients receive misdiagnoses based on an evaluation of coarse facial features. By analyzing three-dimensional images of CS faces, we quantified facial dysmorphology in a cohort of both male and female CS patients with confirmed ABCC9 variants. Morphometric analysis of different regions of the face revealed gender-specific significant differences in face shape. Moreover, we show that 3D facial photographs can distinguish between CS and other genetic disorders with specific facial dysmorphologies that have been mistaken for CS-associated anomalies in the past, hence assisting in an earlier clinical and molecular diagnosis. This optimizes genetic counseling and reduces stress for patients and parents by avoiding unnecessary misdiagnosis.

Perspective Morphometric Criteria for Facial Beauty and Proportion Assessment

Common sense usually considers the assessment of female human attractiveness to be subjective. Nevertheless, in the past decades, several studies and experiments showed that an objective component in beauty assessment exists and can be strictly related, even if it does not match, with proportions of features. Proportions can be studied through analysis of the face, which relies on landmarks, i.e., specific points on the facial surface, which are shared by everyone, and measurements between them. In this work, several measures have been gathered from studies in the literature considering datasets of beautiful women to build a set of measures that can be defined as suggestive of female attractiveness. The resulting set consists of 29 measures applied to a public dataset, the Bosphorus database, whose faces have been both analyzed by the developed methodology based on the expanded set of measures and judged by human observers. Results show that the set of chosen measures is significant in terms of attractiveness evaluation, confirming the key role of proportions in beauty assessment; furthermore, the sorting of identified measures has been performed to identify the most significant canons involved in the evaluation.

Dipyridamole-loaded 3D-printed bioceramic scaffolds stimulate pediatric bone regeneration in vivo without disruption of craniofacial growth through facial maturity

This study investigates a comprehensive model of bone regeneration capacity of dypiridamole-loaded 3D-printed bioceramic (DIPY-3DPBC) scaffolds composed of 100% beta-tricalcium phosphate (β -TCP) in an immature rabbit model through the time of facial maturity. The efficacy of this construct was compared to autologous bone graft, the clinical standard of care in pediatric craniofacial reconstruction, with attention paid to volume of regenerated bone by 3D reconstruction, histologic and mechanical properties of regenerated bone, and long-term safety regarding potential craniofacial growth restriction. Additionally, long-term degradation of scaffold constructs was evaluated. At 24 weeks in vivo, DIPY-3DPBC scaffolds demonstrated volumetrically significant osteogenic regeneration of calvarial and alveolar defects comparable to autogenous bone graft with favorable biodegradation of the bioactive ceramic component in vivo. Characterization of regenerated bone reveals osteogenesis of organized, vascularized bone with histologic and mechanical characteristics comparable to native bone. Radiographic and histologic analyses were consistent with patent craniofacial sutures. Lastly, through application of 3D morphometric facial surface analysis, our results support that DIPY-3DPBC scaffolds do not cause premature closure of sutures and preserve normal craniofacial growth. Based on this novel evaluation model, this DIPY-3DPBC scaffold strategy is a promising candidate as a safe, efficacious pediatric bone tissue engineering strategy.

Ontogeny of the facial phenotypic variability in Mexican patients with 22q11.2 deletion syndrome

Background

22q11.2 deletion syndrome is a medical condition that results from genomic loss at chromosome 22. Affected patients exhibit large variability that ranges from a severe condition to mild symptoms. In addition, the spectrum of clinical features differs among populations and even within family members. The facial features related to this syndrome are not an exception, and although part of its variation arises through development, few studies address this topic in order to understand the intra and inter-population heterogeneities. Here, we analyze the ontogenetic dynamics of facial morphology of Mexican patients with del22q11.2 syndrome.

Methods

Frontal facial photographs of 37 patients (mean age = 7.65 ± 4.21 SE) with del22q11.2DS and 200 control subjects (mean age = 7.69 ± 4.26 SE) were analyzed using geometric morphometric methods. Overall mean shape and size differences between patients and controls were analyzed, as well as differences in ontogenetic trajectories (i.e. development, growth, and allometry).

Results

We found that Mexican patients show typical traits that have been reported for the Caucasian population. Additionally, there were significant differences between groups in the facial shape and size when all the ontogenetic stages were considered together and, along ontogeny. The developmental and allometric trajectories of patients and controls were similar, but they differed in allometric scaling. Finally, patients and controls showed different growth trajectories.

Conclusion

The results suggest that the typical face of patients with del22q11.2DS is established prenatally; nonetheless, the postnatal ontogeny could influence the dysmorphology and its variability through size-related changes.

A Hierarchical Curve-Based Approach to the Analysis of Manifold Data

One of the data structures generated by medical imaging technology is high resolution point clouds representing anatomical surfaces. Stereophotogrammetry and laser scanning are two widely available sources of this kind of data. A standardised surface representation is required to provide a meaningful correspondence across different images as a basis for statistical analysis. Point locations with anatomical definitions, referred to as landmarks, have been the traditional approach. Landmarks can also be taken as the starting point for more general surface representations, often using templates which are warped on to an observed surface by matching landmark positions and subsequent local adjustment of the surface. The aim of the present paper is to provide a new approach which places anatomical curves at the heart of the surface representation and its analysis. Curves provide intermediate structures which capture the principal features of the manifold (surface) of interest through its ridges and valleys. As landmarks are often available these are used as anchoring points, but surface curvature information is the principal guide in estimating the curve locations. The surface patches between these curves are relatively flat and can be represented in a standardised manner by appropriate surface transects to give a complete surface model. This new approach does not require the use of a template, reference sample or any external information to guide the method and, when compared with a surface based approach, the estimation of curves is shown to have improved performance. In addition, examples involving applications to mussel shells and human faces show that the analysis of curve information can deliver more targeted and effective insight than the use of full surface information.

A novel anatomical consideration on the exposed segment of the facial artery

An understanding of the location and depth of the facial artery (FA) is essential in aesthetic surgery and various cosmetic procedures. The purpose of this study was to clarify the three-dimensional (3D) topography of the exposed segment (ES) of the FA and to provide information to help minimize complications during clinical procedures. From 50 embalmed adult cadavers, the undissected and dissected hemifaces were scanned and reconstructed using the 3D scanner. Then the topographic location of the ES was identified and measured from the superimposed the 3D images. The ES was observed in 82% of the whole specimens. The exposure patterns of the ES were examined, and classified into three types: Type I, one site exposed pattern (74%); Type II, two sites exposed pattern (8%); and Type III, nonexposed pattern (18%). The extent of the ES was located at 2.2 mm above and 4.2 mm below the cheilion (Ch)-otobasion inferius line, and 20.0 to 25.2 mm from the Ch on the lateral aspect. In the frontal view, the average distance from the mid-pupillary line to the ES was 7.1 mm, and from the lateral canthal line to the ES was 6.1 mm. The ES was 7.6 mm below the skin surface. The results of this study will help to provide safe guidelines for filler injections as well as selecting the safe regions in various clinical procedures. Clin. Anat. 33:257-264, 2020. © 2019 Wiley Periodicals, Inc.

Three-dimensional facial development of children with unilateral cleft lip and palate during the first year of life in comparison with normative average faces

BACKGROUND

Stereophotogrammetry can be used to study facial morphology in both healthy individuals as well as subjects with orofacial clefts because it shows good reliability, ability to capture images rapidly, archival capabilities, and high resolution, and does not require ionizing radiation. This study aimed to compare the three-dimensional (3D) facial morphology of infants born with unilateral cleft lip and palate (UCLP) with an age-matched normative 3D average face before and after primary closure of the lip and soft palate.

METHODS

Thirty infants with a non-syndromic complete unilateral cleft lip, alveolus, and palate participated in the study. Three-dimensional images were acquired at 3, 6, 9, and 12 months of age. All subjects were treated according to the primary surgical protocol consisting of surgical closure of the lip and the soft palate at 6 months of age. Three-dimensional images of UCLP patients at 3, 6 (pre-treatment), 9, and 12 months of age were superimposed on normative datasets of average facial morphology using the children's reference frame. Distance maps of the complete 3D facial surface and the nose, upper lip, chin, forehead, and cheek regions were developed.

RESULTS

Assessments of the facial morphology of UCLP and control subjects by using color-distance maps showed large differences in the upper lip region at the location of the cleft defect and an asymmetry at the nostrils at 3 and 6 months of age. At 9 months of age, the labial symmetry was completely restored although the tip of the nose towards the unaffected side showed some remnant asymmetry. At 12 months of age, the symmetry of the nose improved, with only some remnant asymmetry noted on both sides of the nasal tip. At all ages, the mandibular and chin regions of the UCLP patients were 2.5-5 mm posterior to those in the average controls.

CONCLUSION

In patients with UCLP deviations from the normative average 3D facial morphology of age-matched control subjects existed for the upper lip, nose, and even the forehead before lip and soft palate closure was performed. Compared to the controls symmetry in the upper lip was restored, and the shape of the upper lip showed less variation after primary lip and soft palate closure. At this early age, retrusion of the soft-tissue mandible and chin, however, seems to be developing already.

Enabling Global Clinical Collaborations on Identifiable Patient Data: The Minerva Initiative

The clinical utility of computational phenotyping for both genetic and rare diseases is increasingly appreciated; however, its true potential is yet to be fully realized. Alongside the growing clinical and research availability of sequencing technologies, precise deep and scalable phenotyping is required to serve unmet need in genetic and rare diseases. To improve the lives of individuals affected with rare diseases through deep phenotyping, global big data interrogation is necessary to aid our understanding of disease biology, assist diagnosis, and develop targeted treatment strategies. This includes the application of cutting-edge machine learning methods to image data. As with most digital tools employed in health care, there are ethical and data governance challenges associated with using identifiable personal image data. There are also risks with failing to deliver on the patient benefits of these new technologies, the biggest of which is posed by data siloing. The Minerva Initiative has been designed to enable the public good of deep phenotyping while mitigating these ethical risks. Its open structure, enabling collaboration and data sharing between individuals, clinicians, researchers and private enterprise, is key for delivering precision public health.

A comparison between 2D and 3D methods of quantifying facial morphology

Objectives

Currently, two & three-dimensional (2D & 3D) imaging techniques have largely replaced the direct anthropometric method in the assessment of facial morphology, but the difference between the two techniques was not quantified. Therefore, the aim of this study was to compare and quantify (the difference between) the two techniques.

Materials and methods

The faces of 150 subjects (75 males, 75 females) of northern Nigeria, predominantly Hausa ethnic group, were photographed (using digital camera) and scanned (using a 3D surface laser scanner). Facial dimensions were generated from the resulting virtual 2D and 3D models. Data were analyzed using R-statistic software & Paired sample t-test/Pearson correlation were conducted to compare the two methods and to quantify the level of closeness between the two measurements.

Results

Intraclass correlation coefficient (ICC) was very low (0.26) for the 3D and 2D measurements indicating the level of differences between the methods. Measurements taken with laser scanner were higher relative to the one taken by camera. The mean differences between the 3D and the 2D methods of quantifying facial morphology indicated a statistically significant positive difference. CONCLUSION: 2D and 3D anthropometry cannot be used interchangeably since there exists statistically significant variation between the two methods.

Regional thickness of facial skin and superficial fat: Application to the minimally invasive procedures

Various recently introduced minimally invasive treatment modalities are now widely used for enhancing the aging face. In a special, filler is used to increase the volume of tissue, and so understanding the regional thickness and distribution of the facial superficial fat is essential for optimizing minimally invasive procedures. The aim of this study was to establish the overall facial skin and superficial fat thicknesses using a three-dimensional (3D) scanning system. From 53 adult Korean and Thai embalmed adult cadavers, the undissected and serially-dissected facial specimens were scanned and reconstructed. The facial skin and superficial fat thicknesses on seven facial regions were calculated from the superimposed images. The facial skin tended to become thicker in the order of the radix and dorsum, and the temple, supraorbital, forehead, perioral, cheek, and infraorbital areas. The skin was thinnest at radix and dorsum (1.51 ± 0.55 mm), and thickest in infraorbital region (1.97 ± 0.84 mm). The facial superficial fat thickness tended to increase in the order of the radix and dorsum, supraorbital, forehead, temple, cheek, infraorbital, and perioral regions. The superficial fat was thinnest at the radix and dorsum (1.61 ± 1.07 mm), and thickest in the perioral region (5.14 ± 3.31 mm). The facial superficial fat thickness tended to increase in the order of the radix and dorsum, supraorbital, forehead, temple, cheek, infraorbital, and perioral regions. The present findings indicate that 3D scanning system can yield crucial anatomical information about depths of the facial skin and superficial fat layers for utilization in various clinical procedures. Clin. Anat. 32:1008-1018, 2019. © 2019 Wiley Periodicals, Inc.

Quantification of mandibular sexual dimorphism during adolescence

The present study investigates how sexual dimorphism in the human mandible develops in three-dimensionally during adolescence. A cross-sectional sample of mandibular meshes of 268 males and 386 females, aged between 8.5 and 19.5 years of age, were derived from cone beam computed tomography and were analysed using geometric morphometric methods. Growth trajectories of the mandible in males and females were modelled separately using a recently developed non-linear kernel regression framework. Growth rate and direction at a dense array of points all over the mandibular surface were visualized within each group and compared between groups. We found that mandibular sexual dimorphism already exists at 9 years of age, but this is mostly in size not in shape. The differential growth rate and duration between the sexes during pubertal growth largely explained by adult sexual dimorphism: the growth direction in both males and females is similar but the male mandible changed more quickly and over a longer period than the female mandible, where the growth rate peaked and declined earlier. This results in increasing dimorphism in form, which is evident in both size and shape. The development of dimorphic features, concentrated in the chin and ramus, were further visualized. The dense morphometric approach provides detailed three-dimensional quantitative assessment of the development of sexual dimorphism of the mandible.

Modeling age-specific facial development in Williams-Beuren-, Noonan-, and 22q11.2 deletion syndromes in cohorts of Czech patients aged 3-18 years: A cross-sectional three-dimensional geometric morphometry analysis of their facial gestalt

Three-dimensional (3D) virtual facial models facilitate genotype-phenotype correlations and diagnostics in clinical dysmorphology. Within cross-sectional analysis of both genders we evaluated facial features in representative cohorts of Czech patients with Williams-Beuren-(WBS; 12 cases), Noonan-(NS; 14), and 22q11.2 deletion syndromes (22q11.2DS; 20) and compared their age-related developmental trajectories to 21 age, sex and ethnically matched controls in 3-18 years of age. Using geometric morphometry statistically significant differences in facial morphology were found in all cases compared to controls. The dysmorphic features observed in WBS were specific and manifested in majority of cases. During ontogenesis, dysmorphic features associated with increased facial convexity become more pronounced whereas other typical features remained relatively stable. Dysmorphic features observed in NS cases were mostly apparent during childhood and gradually diminished with age. Facial development had a similar progress as in controls, while there has been increased growth of patients' nose and chin in adulthood. Facial characteristics observed in 22q11.2DS, except for hypoplastic alae nasi, did not correspond with the standard description of its facial phenotype because of marked facial heterogeneity of this clinical entity. Because of the sensitivity of 3D facial morphometry we were able to reach statistical significance even in smaller retrospective patient cohorts, which proves its clinical utility within the routine setting.

Objectifying Micrognathia Using Three-Dimensional Photogrammetric Analysis

BACKGROUND

Micrognathia occurs isolated and as part of entities like Robin sequence (RS). An objective measurement of mandible size and growth is needed to determine the degree of micrognathia and enable a comparison of treatment outcomes. A pilot study was conducted to investigate the usability of 3-dimensional (3D) facial photogrammetry, a fast, noninvasive method, to estimate mandible size and growth in a small cohort of newborns and infants.

METHODS

Exterior mandibular volume was estimated using a tetrahedron defined by 4 facial landmarks. Twelve patients with RS with different etiologies were selected and photogrammetric images were obtained prospectively in 3 patients with RS in whom mandibular growth in the first year of life was determined. We used 3 tetrahedra defined by 6 landmarks on mandibular computed tomography (CT) scans to estimate an interior mandibular volume, which we compared to the exterior mandibular volume in 10 patients.

RESULTS

The exterior mandibular volume using 3D photography could be determined in all patients. Signature heat maps allowed visualization of facial dysmorphism in 3D; signature graphs demonstrated similarities of facial dysmorphism in patients with the same etiology and differences from those with other diagnoses and from controls. The correlation between interior (3D photogrammetry) and exterior mandibular volumes (CT imaging) was 0.8789.

CONCLUSION

The 3D facial photogrammetry delineates the general facial characteristics in patients with different syndromes involving micrognathia, and can objectively estimate mandibular volume and growth, with excellent correlation with bony measurement. It has been concluded that 3D facial photogrammetry could be a clinically effective instrument for delineating and quantifying micrognathia.

Using principal component analysis to describe the midfacial deformities in patients with craniofacial microsomia

PURPOSE

Craniofacial microsomia (CFM) is the result of a disturbance in embryologic development and is characterised by an asymmetric, mostly unilateral facial underdevelopment. The aim of this study is to understand the midfacial involvement in CFM using principal component analysis (PCA).

MATERIALS AND METHODS

Pre-operative data from 19 CFM and 23 control patients were collected. A set of 71 landmarks was placed on three-dimensional (3D) reconstructions of all skulls to compare both populations. PCA visualised variation within both groups and calculated the vector of change. Linear measurements were taken to compare ratios between the populations and between the affected and unaffected sides in CFM patients.

RESULTS

PCA defined a vector that described shape changes between both populations. Videos showed the variation within the control and CFM group and the transformation from a mean CFM skull into a normal phenotype. Linear measurements showed a significant difference between the affected and unaffected sides in CFM patients.

CONCLUSION

PCA has not been applied on asymmetrical data before, but it has proved to be a useful method to describe CFM. The virtual normalisation of a mean CFM skull enables visualisation of the bony shape changes, which is promising to delineate and to plan surgical correction and could be used as an outcome measure.

Assessing the outcome of orthognathic surgery by three-dimensional soft tissue analysis

Studies of orthognathic surgery often focus on pre-surgical versus post-surgical changes in facial shape. In contrast, this study provides an innovative comparison between post-surgical and control shape. Forty orthognathic surgery patients were included, who underwent three different types of surgical correction: Le Fort I maxillary advancement, bilateral sagittal split mandibular advancement, and bimaxillary advancement surgery. Control facial images were captured from volunteers from local communities in Glasgow, with patterns of age, sex, and ethnic background that matched those of the surgical patients. Facial models were fitted and Procrustes registration and principal components analysis used to allow quantitative analysis, including the comparison of group mean shape and mean asymmetry. The primary characteristic of the difference in shape was found to be residual mandibular prognathism in the group of female patients who underwent Le Fort I maxillary advancement. Individual cases were assessed against this type of shape difference, using a quantitative scale to aid clinical audit. Analysis of the combined surgical groups provided strong evidence that surgery reduces asymmetry in some parts of the face such as the upper lip region. No evidence was found that mean asymmetry in post-surgical patients is greater than that in controls.

Modelling 3D craniofacial growth trajectories for population comparison and classification illustrated using sex-differences

Many disorders present with characteristic abnormalities of the craniofacial complex. Precise descriptions of how and when these abnormalities emerge and change during childhood and adolescence can inform our understanding of their underlying pathology and facilitate diagnosis from craniofacial shape. In this paper we develop a framework for analysing how anatomical differences between populations emerge and change over time, and for binary group classification that adapts to the age of each participant. As a proxy for a disease-control comparison we use a database of 3D photographs of normally developing boys and girls to examine emerging sex-differences. Essentially we define 3D craniofacial 'growth curves' for each sex. Differences in the forehead, upper lip, chin and nose emerge primarily from different growth rates between the groups, whereas differences in the buccal region involve different growth directions. Differences in the forehead, buccal region and chin are evident before puberty, challenging the view that sex differences result from pubertal hormone levels. Classification accuracy was best for older children. This paper represents a significant methodological advance for the study of facial differences between growing populations and comprehensively describes developing craniofacial sex differences.

Estimating age and synthesising growth in children and adolescents using 3D facial prototypes

3D facial images are becoming increasingly common. They provide more information about facial form than their 2D counterparts and will be useful in future forensic applications. These include age estimation and predicting changes in appearance of missing persons (synthetic growth). We present a framework for both age estimation and synthetic growth of children and adolescents from 3D photographs. Age estimation accuracy was substantially better than for existing approaches (mean absolute error=1.19 years). Our synthetically 'grown' images were compared to actual longitudinal images of the same cases. On average 75% of the head overall and 85% of the face were predicted correctly to within three millimetres. We find that our approach is most suitable for ageing children from late childhood into adolescence. The work can be improved in the future by modelling skin colouring and taking account of other factors that influence face shape such as BMI.

Three-dimensional imaging of soft and hard facial tissues in patients with craniofacial syndromes: a systematic review of methodological quality

OBJECTIVES

To systematically review the methodological quality of three-dimensional imaging studies of patients with craniofacial syndromes and to propose recommendations for future research.

METHODS

PubMed, Embase and Cochrane databases as well as Grey literature were electronically searched. Inclusion criteria were patients with genetic syndromes with craniofacial manifestations and three-dimensional imaging of facial soft and/or hard tissues. Exclusion criteria consisted of non-syndromic conditions or conditions owing to environmental causes, injury or trauma, facial soft and hard tissues not included in the image analysis, case reports, reviews, opinion articles. No restrictions were made for patients' ethnicity nor age, publication language or publication date. Study quality was evaluated using the Methodological Index for Non-Randomized Studies (MINORS).

RESULTS

The search yielded 2228 citations of which 116 were assessed in detail and 60 were eventually included in this review. Studies showed a large heterogeneity in study design, sample size and patient age. An increase was observed in the amount of studies with time, and the imaging method most often used was CT. The most studied craniofacial syndromes were Treacher Collins, Crouzon and Apert syndrome. The articles could be divided into three main groups: diagnostic studies (34/60, 57%), evaluation of surgical outcomes (21/60, 35%) and evaluation of imaging techniques (5/60, 8%). For comparative studies, the median MINORS score was 13 (12-15, 25-75th percentile), and for non-comparative studies, the median MINORS score was 8 (7-9, 25-75th percentile).

CONCLUSIONS

The median MINORS scores were only 50 and 54% of the maximum scores and there was a lack of prospective, controlled trials with sufficiently large study groups. To improve the quality of future studies in this domain and given the low incidence of craniofacial syndromes, more prospective multicentre controlled trials should be set up.

The enduring impact of neurulation stage alcohol exposure: A combined behavioral and structural neuroimaging study in adult male and female C57BL/6J mice

Prenatal alcohol exposure (PAE) can cause behavioral and brain alterations over the lifespan. In animal models, these effects can occur following PAE confined to critical developmental periods, equivalent to the third and fourth weeks of human gestation, before pregnancy is usually recognized. The current study focuses on PAE during early neurulation and examines the behavioral and brain structural consequences that appear in adulthood. On gestational day 8 C57BL/6J dams received two alcohol (2.8g/kg, i.p), or vehicle, administrations, four hours apart. Male and female offspring were reared to adulthood and examined for performance on the elevated plus maze, rotarod, open field, Morris water maze, acoustic startle, social preference (i.e. three-chambered social approach test), and the hot plate. A subset of these mice was later evaluated using magnetic resonance imaging to detect changes in regional brain volumes and shapes. In males, PAE increased exploratory behaviors on the elevated plus maze and in the open field; these changes were associated with increased fractional anisotropy in the anterior commissure. In females, PAE reduced social preference and the startle response, and decreased cerebral cortex and brain stem volumes. Vehicle-treated females had larger pituitaries than did vehicle-treated males, but PAE attenuated this sex difference. In males, pituitary size correlated with open field activity, while in females, pituitary size correlated with social activity. These findings indicate that early neurulation PAE causes sex specific behavioral and brain changes in adulthood. Changes in the pituitary suggest that this structure is especially vulnerable to neurulation stage PAE.

The facial morphology in Down syndrome: A 3D comparison of patients with and without obstructive sleep apnea

Obstructive sleep apnea (OSA) occurs at a high prevalence in patients with Down syndrome (DS). A polysomnogram, which is often cumbersome and challenging, remains the gold standard method of diagnosing OSA. OSA in patients with DS is often attributed to skeletal and soft-tissue structural alterations that are characteristic of the DS phenotype; as such, we hypothesized that assessing anthropometric facial measurements may be predictive of OSA in patients with DS. We used the 3dMDface sterophotography system to capture and create 3D facial images, and we subsequently identified facial landmarks using a single, experienced investigator and utilizing proprietary software to calculate inter-landmark distances and angles. We compared our findings with similar data for neurotypically developing participants. We further compared the findings in participants with DS with and without OSA. Participants with DS had maxillomandibular hypoplasia with smaller ear, nose, and eye measurements compared to neurotypically developing peers. We found no statistically significant differences in 3D photogrammetric measurements between participants with DS with or without OSA.

Noonan syndrome in diverse populations

Noonan syndrome (NS) is a common genetic syndrome associated with gain of function variants in genes in the Ras/MAPK pathway. The phenotype of NS has been well characterized in populations of European descent with less attention given to other groups. In this study, individuals from diverse populations with NS were evaluated clinically and by facial analysis technology. Clinical data and images from 125 individuals with NS were obtained from 20 countries with an average age of 8 years and female composition of 46%. Individuals were grouped into categories of African descent (African), Asian, Latin American, and additional/other. Across these different population groups, NS was phenotypically similar with only 2 of 21 clinical elements showing a statistically significant difference. The most common clinical characteristics found in all population groups included widely spaced eyes and low-set ears in 80% or greater of participants, short stature in more than 70%, and pulmonary stenosis in roughly half of study individuals. Using facial analysis technology, we compared 161 Caucasian, African, Asian, and Latin American individuals with NS with 161 gender and age matched controls and found that sensitivity was equal to or greater than 94% for all groups, and specificity was equal to or greater than 90%. In summary, we present consistent clinical findings from global populations with NS and additionally demonstrate how facial analysis technology can support clinicians in making accurate NS diagnoses. This work will assist in earlier detection and in increasing recognition of NS throughout the world.

Facial Curvature Detects and Explicates Ethnic Differences in Effects of Prenatal Alcohol Exposure

BACKGROUND

Our objective is to help clinicians detect the facial effects of prenatal alcohol exposure by developing computer-based tools for screening facial form.

METHODS

All 415 individuals considered were evaluated by expert dysmorphologists and categorized as (i) healthy control (HC), (ii) fetal alcohol syndrome (FAS), or (iii) heavily prenatally alcohol exposed (HE) but not clinically diagnosable as FAS; 3D facial photographs were used to build models of facial form to support discrimination studies. Surface curvature-based delineations of facial form were introduced.

RESULTS

(i) Facial growth in FAS, HE, and control subgroups is similar in both cohorts. (ii) Cohort consistency of agreement between clinical diagnosis and HC-FAS facial form classification is lower for midline facial regions and higher for nonmidline regions. (iii) Specific HC-FAS differences within and between the cohorts include: for HC, a smoother philtrum in Cape Coloured individuals; for FAS, a smoother philtrum in Caucasians; for control-FAS philtrum difference, greater homogeneity in Caucasians; for control-FAS face difference, greater homogeneity in Cape Coloured individuals. (iv) Curvature changes in facial profile induced by prenatal alcohol exposure are more homogeneous and greater in Cape Coloureds than in Caucasians. (v) The Caucasian HE subset divides into clusters with control-like and FAS-like facial dysmorphism. The Cape Coloured HE subset is similarly divided for nonmidline facial regions but not clearly for midline structures. (vi) The Cape Coloured HE subset with control-like facial dysmorphism shows orbital hypertelorism.

CONCLUSIONS

Facial curvature assists the recognition of the effects of prenatal alcohol exposure and helps explain why different facial regions result in inconsistent control-FAS discrimination rates in disparate ethnic groups. Heavy prenatal alcohol exposure can give rise to orbital hypertelorism, supporting a long-standing suggestion that prenatal alcohol exposure at a particular time causes increased separation of the brain hemispheres with a concomitant increase in orbital separation.

A three-dimensional soft tissue analysis of Class III malocclusion: a case-controlled cross-sectional study

OBJECTIVE

The present study used the optical surface laser scanning technique to compare the facial features of patients aged 8-18 years presenting with Class I and Class III incisor relationship in a case-control design.

MATERIALS AND METHODS

Subjects with a Class III incisor relationship, aged 8-18 years, were age and gender matched with Class I control and underwent a 3-dimensional (3-D) optical surface scan of the facial soft tissues.

RESULTS

Landmark analysis revealed Class III subjects displayed greater mean dimensions compared to the control group most notably between the ages of 8-10 and 17-18 years in both males and females, in respect of antero-posterior (P = 0.01) and vertical (P = 0.006) facial dimensions. Surface-based analysis, revealed the greatest difference in the lower facial region, followed by the mid-face, whilst the upper face remained fairly consistent.

CONCLUSION

Significant detectable differences were found in the surface facial features of developing Class III subjects.

The Effect of Nasal Tip Rotation on Upper Lip Length

Background

Increasing the nasolabial angle (NLA) with tip rotation generates the appearance of a lengthened lower facial third. In particular, the upper lip show seems increased following elevation of the nasal tip.

Objectives

The purpose of this study is to quantify the impact of tip rotation on upper lip length (ULL), and to establish a predictable correlation between the two.

Methods

A retrospective cohort study of rhinoplasty patients with increased tip rotation, using either caudal septal extension graft (CSEG) or columellar strut graft (CS), was performed. Three-dimensional photos were obtained and analyzed anthropometrically and used to measure the ULL and NLA. The deltas between NLA and ULL at the various time points, was then compared using linear regression with P < .05 recognized as statistically significant.

Results

One-hundred and fifty patients were identified and 88 patients met inclusion criteria. CS and CSEG were used in 40% (n = 36), and 60% (n = 52), respectively. Three-dimensional assessment showed that as the NLA positively correlated with the ULL in both cohorts. The CSEG group created a greater NLA and ULL compared to the CS cohort. Both NLA and ULL decreased over time, but remained statistically increased as compared with preoperative measurements. For every one degree of NLA increase, the ULL increases by 0.05 mm.

Conclusions

Increasing nasal tip rotation in rhinoplasty results in greater upper lip show. Both CS and CSEG can effectively increase tip rotation and ULL. A predictable correlation of nearly 0.05 mm of ULL for every 1 degree of tip rotation is shown.

Level of Evidence

4.

Application of off-the-shelf stereo-cameras for the 3D assessment of morphometric variations caused by rhinoplasty

The present paper shows how a non-invasive and low-cost photogrammetric stereo device allows the assessment of morphometric variations of the nose following rhinoplasty. Six female patients, aged between 24 and 37 years, underwent 3D stereo-photogrammetric scanning. Three-dimensional computerised models were generated, extracting also information related to the coordinates of facial landmarks, distances between landmarks, angles, in pre- and postoperative situation. Two kinds of analysis were carried out: (i) statistical correlation between size variations and (ii) morphometric analysis, including General Procrustes Analysis (GPA), Principal Components Analysis (PCA) and Warping. The study shows the usefulness of the stereo-photogrammetric facial digitisation for morphometric analysis of the human face. Three-dimensional computerised models are also an important tool for the assessment of the surgeon's performance in the event of dispute between doctor and patient. Moreover, confirmation of the PCA as an analytical tool for the identification of components characterising the morphometric structure of the nose is highlighted.

Three-Dimensional Anthropometric Database of Attractive Caucasian Women: Standards and Comparisons

The aim of this paper is to develop a database to determine a new biomorphometric standard of attractiveness. Sampling was carried out using noninvasive three-dimensional relief methods to measure the soft tissues of the face. These anthropometric measurements were analyzed to verify the existence of any canons with respect to shape, size, and measurement proportions which proved to be significant with regard to the aesthetics of the face. Finally, the anthropometric parameters obtained were compared with findings described in the international literature.

The study sample was made up competitors in the Miss Italy 2010 and 2009 beauty contest. The three-dimensional (3D) scanning of soft tissue surfaces allowed 3D digital models of the faces and the spatial 3D coordinates of 25 anthropometric landmarks to be obtained and used to calculate linear and angular measurements. A paired Student t test for the analysis of the means allowed 3 key questions in the study of biomorphometric parameters of the face to be addressed through comparison with the data available in the literature.

The question of statistical evidence for the samples analyzed being members of the populations samples reported in literature was also addressed.

The critical analysis of the data helped to identify the anthropometric measurements of the upper, middle, and lower thirds of the face, variations in which have a major influence on the attractiveness of the face. These changes involve facial width, height, and depth. Changes in measurements of length, angles, and proportions found in the sample considered were also analyzed.