Analysis of the anthropometric measurements of the smile using 3D stereophotogrammetry / Análise das medidas antropométricas do sorriso utilizando a estereofotogrametria 3D

3D stereophotogrammetry makes the analysis of facial soft tissues possible, and has the potential to contribute to human identification processes. Nowadays, the images available through social networks are composed of a significant amount of smile photos, making techniques such as 3D stereophotogrammetry relevant. The objective of the present study was to quantitatively analyze the anthropometric measurements of the smile through 3D stereophotogrammetry, including area, angular, and linear measurements. Anatomical landmarks were used to make possible the area, angular, and linear measurements. The sample consisted of 25 volunteers, 13 female and 12 male, both in the 19-25 age group, resulting in a mean age of 22.31.9 and 23.31.5, respectively. The anatomical landmarks were marked on the face of the volunteers using a black eyeliner, and the photographs were taken using the 3D stereophotogrammetry technique (Vectra H1, Canfield, NY, USA), being 3 photographs with a spontaneous smile and 3 at rest, right lateral, left lateral and frontal of each. Among the results of the comparison between genders and the photo/smile relation of the statistical analysis, variables such as the mentolabial angle and the vermilion height of the upper lip showed significant p-values of 0.046 and 0.014, respectively. It can be concluded that anthropometric measurements of three-dimensional smile images can be performed with the use of 3D stereophotogrammetry, with the purpose of contributing to facial identification methods

A estereofotogrametria 3D possibilita a análise dos tecidos moles faciais e tem o potencial de contribuir para os processos de identificação humana. Atualmente, as imagens disponíveis nas redes sociais são compostas por uma quantidade significativa de fotos de sorrisos, tornando relevante técnicas como a estereofotogrametria 3D. O objetivo do presente estudo foi analisar quantitativamente as medidas antropométricas do sorriso por meio da estereofotogrametria 3D, incluindo medidas de área, angulares e lineares. Referenciais anatômicos foram utilizados para possibilitar as medidas de área, angulares e lineares. A amostra foi composta por 25 voluntários, sendo 13 do sexo feminino e 12 do sexo masculino, ambos na faixa etária de 19 a 25 anos, resultando em média de idade de 22,3±1,9 e 23,3±1,5, respectivamente. Os referenciais anatômicos foram marcados na face dos voluntários com delineador preto e as fotografias foram realizadas pela técnica de estereofotogrametria 3D (Vectra H1, Canfield, NY, EUA), sendo 3 fotografias com sorriso espontâneo e 3 em repouso, direita lateral, esquerda lateral e frontal de cada um. Dentre os resultados da comparação entre gêneros e relação foto/sorriso da análise estatística, variáveis como o ângulo mentolabial e a altura do vermelhão do lábio superior apresentaram valores de p significativos de 0,046 e 0,014, respectivamente. Pode-se concluir que medidas antropométricas de imagens tridimensionais do sorriso podem ser realizadas com o uso da estereofotogrametria 3D, com a finalidade de contribuir com os métodos de identificação facial

Comparison of the accuracy of two⁃dimensional and three⁃dimensional photography in the facial measuremenof patients with unilateral cleft lip t / 口腔疾病防治

Objective@#To compare the measurement accuracy of two⁃dimensional (2D) photography and three⁃di⁃mensional (3D) photography in the analysis of the asymmetric appearance of children with cleft lip and palate and the influence of the severity of asymmetric deformity on the accuracy of facial measurement to guide clinical measurement work@* Methods@#Children with unilateral cleft lip were enrolled in this prospective study. Seven parameters⁃⁃the devia⁃tion of the pronasale, subnasale, and labrale superius, as well as the cleft/noncleft ratio of the width of nostrils, length and height of lateral lips and height of columella⁃were measured with Vernier calipers as the gold standard. Traditional 2D photography and 3D stereophotogrammetry photos were taken and measured. The extent of cleft malformation is indi⁃cated by the ratio of the cleft side to the noncleft side. The error size is represented by the ratio difference between two⁃dimensional photography or stereophotogrammetry with the ratio of the gold standard@* Results@#Thirteen patients were eventually recruited. The measurement results of the ratio of lateral lip height by 2D photography tended to be larger (P＝0.019), and the measurement results of the ratio of columella height tended to be smaller (P＝0.008). The measure⁃ment results of the deviation of the subnasale by stereophotogrammetry tended to be smaller (P＝0.003). The pronasale deviation (P＝0.022) with two⁃dimensional photography, the deviation of the labrale superius (P＝0.025) and the ratio of lateral lip length (P＝0.036) with stereophotogrammetry had a significant negative correlation with the extent of cleft malformation@* Conclusion@#Both two⁃dimensional photography and stereophotogrammetry have errors and biases that underexaggerate or overexaggerate the extent of cleft malformation, and some errors may increase with the decrease in the extent of cleft malformation. When applying two⁃dimensional and three⁃dimensional photography to analyze cleft lip and palate deformities, these biases should be considered to evaluate the face more objectively

Validation of a low-cost portable 3-dimensional face scanner

PURPOSE: The goal of this study was to assess the accuracy and reliability of a low-cost portable scanner (Scanify) for imaging facial casts compared to a previously validated portable digital stereophotogrammetry device (Vectra H1). This in vitro study was performed using 2 facial casts obtained by recording impressions of the authors, at King's College London Academic Centre of Reconstructive Science. MATERIALS AND METHODS: The casts were marked with anthropometric landmarks, then digitised using Scanify and Vectra H1. Computed tomography (CT) scans of the same casts were performed to verify the validation of Vectra H1. The 3-dimensional (3D) images acquired with each device were compared using linear measurements and 3D surface analysis software. RESULTS: Overall, 91% of the linear Scanify measurements were within 1 mm of the corresponding reference values. The mean overall surface difference between the Scanify and Vectra images was <0.3 mm. Significant differences were detected in depth measurements. Merging multiple Scanify images produced significantly greater registration error. CONCLUSION: Scanify is a very low-cost device that could have clinical applications for facial imaging if imaging errors could be corrected by a future software update or hardware revision.

Accuracy evaluation of tridimensional images performed by portable stereophotogrammetric system / Avaliação da acurácia de imagens tridimensionais realizadas em sistema de estereofotogrametria portátil

Abstract Introduction Human facial characteristics vary according to individual dental occlusion, facial harmony, orofacial musculature and the format and configuration of craniofacial structures. Traditionally, anthropometric measurements have been acquired through direct evaluation of subjects in a clinical environment using calipers and metric tapes to measure distances between arches and landmarks. Scientific breakthroughs have enabled the digitization of data and introduced the possibility of quick, precise, radiation-free acquisitions; details can be archived for future analysis and easily shared with patients and colleagues. Among new facial analysis methods, the stereophotogrammetry technique has emerged, which uses a group of cameras to take many photographs of a subject in rapid succession from multiple angles. Nowadays, portable stereophotogrammetric systems are being proposed, as they are more practical and easier to use. Objective The aim of this work was to analyze the accuracy and reproducibility of a portable 3D stereophotogrammetric system (Vectra H1, Canfield, Fairfield, NJ, USA) in measuring soft facial tissues of 30 participants, defining measures of a cube and comparing these measurements with those obtained by a set 3D stereophotogrammetric system (Vectra M3, Canfield, Fairfield, NJ, USA) with previously validated accuracy and reproducibility through quantitative analysis of possible errors. Material and method Thirty temporary landmarks were used to measure (in mm) 34 distances in 30 participants (n = 30). Regarding the cube, 12 angles and 9 linear distances were evaluated. Result The results obtained by the established methodology indicated that the Vectra H1 portable system has shown accuracy and reproducibility equal to that of the Vectra M3 set system. Conclusion Data analysis and correlation to literature findings show Vectra H1's capability to reliably capture tridimensional images, which makes it practical for use in diverse clinical applications.

Resumo Introdução A configuração e o formato das estruturas craniofaciais, a oclusão dentária, a musculatura orofacial bem como a harmonia facial são determinantes para as características próprias da face humana. Instrumentos manuais como paquímetro e fitas métricas têm sido tradicionalmente utilizados para realizar as medidas antropométricas, diretamente de um sujeito em ambiente clínico. O avanço tecnológico possibilitou transformar a aquisição destas medidas analógicas em medições digitais, tornando possível aquisições rápidas, precisas e sem radiação. Tais informações podem, ainda, ser arquivadas para futuras análises e compartilhamento de informações com colegas e pacientes. A estereofotogrametria tem se destacado dentre as novas técnicas de captação de imagens tridimensionais, onde um grupo de câmeras de rápida captura fotografam a imagem do indivíduo a partir de variadas angulações. Atualmente, sistemas portáteis de estereofotogrametria vêm sendo propostos no mercado por apresentarem maior praticidade e simplicidade no manuseio. Objetivo A proposta do presente estudo foi avaliar a precisão e a reprodutibilidade de um sistema de estereofotogrametria 3D portátil (Vectra H1, Canfield Scientific, Fairfield, NJ, EUA) em medições dos tecidos moles faciais de 30 participantes e de um cubo de medidas definidas, comparando tais medidas com as obtidas por um sistema de estereofotogrametria 3D fixo (Vectra M3, Canfield Scientific, Fairfield, NJ, EUA), de precisão e reprodutibilidade estabelecidas e validadas, através de análise quantitativa dos possíveis erros. Material e método Foram realizadas marcações craniométricas transitórias em tecido mole da face nos 30 participantes do estudo (n=30), sendo estes submetidos à aquisição de imagens pela técnica da estereofotogrametria, tanto pelo sistema fixo Vectra M3, quanto pelo sistema portátil Vectra H1. Trinta pontos de referência (landmarks) foram utilizados para realizar as medidas (em mm) de 34 distâncias. Quanto ao cubo, foram avaliados, no total, 20 ângulos, 20 áreas e 9 distâncias lineares. Resultado Os resultados obtidos pela metodologia estabelecida mostraram que o sistema portátil Vectra H1 apresentou precisão e repetibilidade comparáveis com o sistema fixo Vectra M3. Conclusão A análise dos dados, juntamente com a correlação aos achados da literatura, evidenciam a capacidade do Vectra H1 de capturar imagens tridimensionais de modo eficaz, o que torna viável seu uso nas mais diversas aplicações clínicas.

Facial anthropometric analysis of a healthy group of young Brazilian adults by means of stereophotogrammetry technique / Análise antropométrica facial de um grupo de jovens adultos brasileiros saudáveis por meio da técnica da estereofotogrametria

Introduction: Anthropometry is the science responsible for measuring the weight, size, and proportions of the human body, providing valuable and objective insights into how to characterize phenotypic variation and dysmorphology. Among the newer methods for facial analysis, the stereophotogrammetry technique has shown excellent results given its use of a group of fast cameras that photograph subjects from multiple angles. Objective: The aims of the present study were: (1) to analyze the facial profile of a group of healthy young Brazilian adults, between 18 and 30 years of age, (2) to define common facial values among the subjects, (3) to create a database of facial measurements of a portion of this young healthy Brazilian population to be used in future works, and (4) to test the precision and repeatability of the Vectra M3® equipment. Material and method: Sixty healthy young Brazilian adults participated in the study, 30 males and 30 females. Temporary craniometrical landmarks were performed in soft tissue, and those subjects underwent image capturing by the stereophotogrammetry technique. Thirty landmarks were used to take the measurements (in mm) of 35 distances. The equipment repeatability was tested in 20% of the sample (i.e., 12 subjects). Result: The values between the first and second acquisitions were statistically (p<0.05) similar for all 35 distances analyzed. The findings allowed the creation of a reliable database containing facial distances of a portion of the young healthy Brazilian population. In addition, the distances Tr-N, N-Sn, Ls-Sto, Sto-Li, En[r]-En[l] and Prn-Sn were not statistically different for the group of men (GM) and the group of women (GW), while the other 29 distances were significantly greater in GM. Conclusion: The technique and methods employed in the study yielded objective analyses of the facial profile of this group of healthy young Brazilian adults, and the equipment Vectra M3® showed a high level of precision and repeatability.

Introdução: Antropometria é a ciência responsável por medir o peso, tamanho e proporções do corpo humano, fornecendo informações objetivas e confiáveis para caracterizar variações e dismorfismos fenotípicos. Entre os novos métodos de análise facial, a técnica da estereofotogrametria tem mostrado excelentes resultados devido o uso de um grupo de câmeras capazes de fotografar sujeitos em múltiplos ângulos. Objetivo: Os objetivos deste estudo foram: (1) analisar o perfil facial de um grupo de jovens adultos saudáveis brasileiros, entre 18 e 30 anos, (2) definir valores comuns entre os sujeitos, (3) criar uma base de dados de medidas faciais de uma porção desta população jovem adulta de brasileiros para ser utilizada em trabalhos futuros, e (4) testar a precisão e repetibilidade do equipamento Vectra M3®. Material e método: Sessenta jovens adultos brasileiros participaram deste estudo, 30 homens e 30 mulheres. Pontos de referência craniométricos temporários foram realizados em tecido mole, e estes sujeitos foram fotografados pela técnica da estereofotogrametria. Trinta pontos de referência foram usados para realizar as medições (em mm) de 35 distâncias. A repetibilidade do equipamento foi testada em 20% da amostra (12 sujeitos). Resultado: Os valores entre a primeira e a segunda aquisição foram estatisticamente (p<0,05) similares para todas as 35 distancias analisadas. Os achados possibilitaram a criação de um banco de dados confiável contendo distâncias de uma porção da população jovem adulta saudável brasileira. Além disso, as distâncias Tr-N, N-Sn, Ls-Sto, Sto-Li, En[r]-En[l] e Prn-Sn não foram estatisticamente diferentes entre o grupo de homens (GM) e o grupo de mulheres (GW), enquanto as outras 29 distâncias foram significativamente maiores em GM. Conclusão: A técnica e os métodos empregados neste estudo possibilitaram análise objetiva do perfil facial de um grupo de jovens adultos saudáveis brasileiros, e o equipamento Vectra M3® mostrou alto nível de precisão e reprodutibilidade.

Feasibility of integrating 3D photos and cone-beam computed tomography images used to evaluate changes of soft and hard tissue after orthognathic surgery / 北京大学学报(医学版)

Objective:To evaluate the feasibility of integrating 3D photos and cone-beam computed tomography (CBCT)images and to assess the degree of error that may occur during the above process,and to analyze soft and hard tissue changes after orthognathic surgery using this new method.Methods:Ten patients with maxillofacial deformities were chosen.For each patient,CBCT scans and stereophotographic images were taken before and 3 months after surgery.3D photos were superimposed onto the CBCT skin im-ages using relatively immobile areas of the face as a reference.3D color maps and mean distances were used to evaluate the errors that might occur during the process.Two reference planes were set up using cer-tain points.The distances between Prn (pronasale),Sn (subnasale),Ls (labrale superior),ANS (anterior nasal spine),A (subspinale),UIE (upper incisor edge)to the coronal plane were calculated before and af-ter surgery.In order to verify the repeatability of this method,we examined the distances twice at two-week intervals.Paired t test was used to evaluate the reproducibility.Results:CBCT and 3D photos could be successfully fused with clinically acceptable errors.This new method could be used to evaluate soft and hard tissue changes after orthognathic surgery.The 3D color maps showed that the two images could be fused with minimal errors.The mean distances were within 0.3 mm,and the locations of landmarks on maxilla and mandible such as Ls,ANS,A,UIE changed significantly after orthognathic surgery (P 0.1 ).The paired t test showed that the mean value and standard deviation were (0.08 ±0.98)mm.Conclusion:Fusing of CBCT and 3D stereophotographic images used as a new method in evaluating soft and hard tissue changes after orthognathic surgery was feasible and accurate.The virtual 3D composite craniofacial models permitted concurrent assess-ment of hard and soft tissues during diagnosis and treatment planning.Maxillary and mandibular locations had significant association with orthoganthic surgery while the nasal tissue was not simp affected by surgery.

The use of stereophotogrammetry in oral surgery: Measurement of area changes after secondary epithelization and grafting vestibuloplasties.

Objective: Stereophotogrammetry (SPT) is a method in which three-dimensional coordinates are calculated from multiple two-dimensional projections. The purpose of this study was to compare the surface area changes between the secondary healing and grafting vestibuloplasty techniques in the mandible by using a stereophotogrammetric technique (SPT). Patients and Methods: Thirteen patients were included in this study: six patients were managed by using full-thickness skin or palatal mucosa grafts (two full-thickness palatal mucosal grafts and four full-thickness skin grafts); the remaining seven patients, who did not accept a second surgery for graft harvesting, underwent secondary epithelization vestibuloplasties. Postoperative changes of surgical areas were measured by using SPT. Statistical Analyses: The Wilcoxon (intragroup comparisons) and Mann-Whitney U (intergroup comparisons) tests were used for analysis of data. Results: In the grafting vestibuloplasty group, the surface area gain was statistically significant (P < 0.05). In the secondary epithelization vestibuloplasty group, there was no significant difference (P > 0.05), with even decrease of surface area being noted in some cases. Conclusion: SPT is a valid method for measurement of intraoral soft tissue changes.

Facial three dimensional surface imaging: an overview

The surface facial imagings have many applications in medical fields. The recent past has seen great advances in three dimensional imaging which include laser scanning or stereophotogrammetry. Here, we reviewed various systems with reference to image acquisition, advantages and disadvantages. Examples of important clinical application with reference to the human face are also discussed. Finally, a 3D imaging system at Universiti Sains Malaysia (USM) is described.