Images Of Skulls Research Articles

3d printing of skull models in horse, ox and pig

In this study, it was aimed to physically create skull models of large-sized animal sample horse, cattle and pig species used in veterinary anatomy education with three-dimensional printing technology and to determine the suitability of these models anatomically. The anatomical structures on the skull models obtained for this purpose were examined comparatively and the advantages and disadvantages of the models in terms of their usability in education were revealed. For the study, 3D reconstruction and segmentation processes were performed digitally on the cross-sectional images of horse, cattle and pig skulls obtained by computed tomography scanning and printed. Anatomical structures were comparatively analyzed on the produced 3d plastic replicas and organic skulls. Anatomical accuracy of the 3d models, printing quality, printing errors, advantages and disadvantages were evaluated. Plastic models were found to be approximately 45% lighter than organic models in horses, 55% lighter in cattle and 60% lighter in pigs. The weight (g)/printing time (s) ratio was calculated as 11.8 for equine skull models, 12.7 for bovine models and 7.4 for porcine models. It was determined that the anatomical accuracy of the models was at a high level, important anatomical structures could be printed in accordance with the original skulls, and only some sutures between the skull bones and holes with a diameter of less than 2 mm could not be clearly visualized due to scanning and printing quality. As a result, it was determined that the plastic replicas obtained can be used in veterinary anatomy education in terms of anatomical accuracy, as well as important advantages such as being lighter, more resistant to effects such as falling, impact, cleaning, easy storage, low cost, reprinting when necessary and making corrections on the model.

Evaluation and 3D imaging of mineral structure changes of the rabbit (New Zealand) skull during developmental periods.

This study aimed to determine the morphometric measurements anatomically and CT images of skulls of healthy male and female rabbits during postnatal development, to analyse the data statistically and to demonstrate the structural changes in bone. A total of 40 rabbits (20 females and 20 males) were divided into four groups including prepubertal period (group I (0-1 month)), period between adolescence and adulthood (group II (3-5 month)) and later (young adult period as group III (1-3 years) and old adult period as group IV (3-5 years)), with five animals in each group. After the morphometric measurements, the surface area and volume values of the skull were calculated. The skulls were reconstructed using a 3D Slicer (5.0.2), which is used for 3D modelling. The cranial bones in each group were then crushed using a grinder so that the powdered samples were obtained for XRF (X-ray fluorescence technique). The p-value was statistically highly significant between group and gender (p < 0.001). In morphometric measurements, males were generally higher than females. Only PL, GBOC and GNB measurements were higher in females. The p-value between groups (in all measurements), between genders (in TL, GLN, FL, VL, OZB and GBN parameters) and between groups and genders (in TL, DL and VL parameters) was statistically highly significant (p < 0.001). The p-value between the groups, p-value between sexes and p-value between group and sex in Si, P, K, Ca, Ni, Zn, Sr, Sr and Ca/P elements were statistically significant (p < 0.001). Consequently, metric, volume and surface area measurements were taken through 3D modelling of skull bone in prepubertal period (group I), period between adolescence and adulthood (group II) and later (young adult period as group III and old adult period as group IV) of rabbits and the change in the mineral structure during postnatal development and effect of sex on this change were investigated. This might be the first study to assess both metric and mineral changes at four age intervals taken during the life span of rabbits.

The Use of Foramen Magnum in The Determination of Sex Using Computed Tomography (CT) Scan Images of Sampled Population Attending National Ear Care Centre Kaduna State, Nigeria

Determination of sex is an important element of human identification which becomes challenging when only only fragments of body parts are available for investigation by forensic experts. This study was aimed at assessing the utility of foramen magnum parameters in the determination of sex among the Nigerian population. A retrospective study was conducted on patients attending National Ear Care Center Kaduna between the years 2017-2019. A total of 399 normal Multislice CT images of skulls (236 males and 163 females) of the age of 18 – 95 years were randomly picked from the archives of the Hospital in the computer database of the Radiology Department. The foramen magnum and occipital condyles parameters were measured by an experienced radiologist. Males tend to have a significantly higher mean value of foramen magnum width, Foramen Magnum Index, the length of the right occipital condyle, and the length of left occipital condyles as well as the width of the right occipital condyle at a p-value ≤ 0.05. The width of right occipital condyles was the only variable that got a significant (p ≤ 0.05) impact on our sex estimation following multiple logistic regression. However, by applying discriminate function analysis the length of the left occipital condyle and width of the right occipital condyle were the only discriminatory variables chosen for this study population. In conclusion, this study indicated that five variables of foramen magnum out of ten were statistically significantly different with males having higher mean values than females. Moreover, the only significant discriminatory variables to determine sex in this study population were the length of the left occipital condyle and the width of the right occipital condyle respectively.

Using 3D images of Korean's mastoid process to estimate sex: A metric study

• We validated a forensic anthropological sex estimation for the mastoid process in Koreans by 3DCT. • The volume of the mastoid process in males was greater than that in females. • Using mastoid process volumes in a metric method increased the accuracy of sex estimation by 20%. • Our metric methods for sex estimation are more applicable to skulls found in the Korea population. • This method helps to increase accuracy and reliability of sex estimation using Korean skulls. This study reports an approach for forensic anthropological sex estimation by examining the mastoid process in Koreans using three-dimensionally reconstructed computed tomography images of skulls. The purpose was to validate this metric sex estimation method using only the mastoid process in a Korean population compared to a non-metric sex estimation method derived from a previously used non-Korean method. In this study, 661 images were gathered and 100 of these were randomly set aside for use in the non-metric method. We then applied our metric analysis to the remaining 561 images. Our findings showed that the volume of the mastoid process in males was greater than that in females. As a result, using the mastoid process volume in a metric method increased the accuracy of sex estimation by 20% compared to that using the non-metric method. Our metric methods for sex estimation are more applicable to skulls found in Korea than to those from non-Korean populations, and the metric methods for sex estimation are more useful than non-metric methods. In future studies, it is necessary to derive new equations from measurements of the glabella, mental eminence, supraorbital margin, and nuchal crest for Korean skulls; this method contributes to increased accuracy and reliability of sex estimation using Korean skulls.

Processes and patterns: Insights on cranial covariation from an Apert syndrome mouse model.

Major cell-to-cell signaling pathways, such as the fibroblast growth factors and their four receptors (FGF/FGFR), are conserved across a variety of animal forms. FGF/FGFRs are necessary to produce several "vertebrate-specific" structures, including the vertebrate head. Here, we examine the effects of the FGFR2 S252W mutation associated with Apert syndrome on patterns of cranial integration. Our data comprise micro-computed tomography images of newborn mouse skulls, bred to express the Fgfr2 S252W mutation exclusively in either neural crest or mesoderm-derived tissues, and mice that express the Fgfr2 S252W mutation ubiquitously. Procrustes-based methods and partial least squares analysis were used to analyze craniofacial integration patterns. We found that deviations in the direction and degree of integrated shape change across the mouse models used in our study were potentially driven by the modular variation generated by differing expression of the Fgfr2 mutation in cranial tissues. Our overall results demonstrate that covariation patterns can be biased by the spatial distribution and magnitude of variation produced by underlying developmental-genetic mechanisms that often impact the phenotype in disproportionate ways.

The Role of Connexin‐43 in Cranial Neural Crest Cell Differentiation

BackgroundMost features of the craniofacial complex that are necessary for feeding derive from cranial neural crest cells (cNCCs). These pluripotent stem cells originate from the dorsal neural folds and undergo a series of coordinated processes such as induction, epithelial‐to‐mesenchymal transition (EMT), migration, and differentiation. While most of these processes have been well‐studied for their roles in development, much remains to be known about the final step cNCCs must undergo, differentiation. Connexin‐43 (Cx43) is a gap junctional protein that is widely expressed, evolutionarily conserved, and has been well‐studied for its impacts on neural crest and bone. Previous research has shown that loss of Cx43 function impacts neural crest EMT and migration and can delay early osteoblast and chondrocyte differentiation; however, it is unknown how Cx43 deficiency in cNCCs impacts cNCC differentiation into osteochondrogenic lineages and the resultant impacts on craniofacial morphology. Therefore, the purpose of this project is to determine the effects of a neural crest‐specific loss of Cx43 on osteogenic and chondrogenic differentiation, and how these effects may alter skull phenotype.MethodsWe have developed a mouse model wherein the gene encoding for Cx43 has been conditionally knocked out in neural crest cells and their derivatives using the Wnt1‐Cre2 driver (Wnt1‐Cre2+/‐;mTmG+/+;Cx43fl/fl, herein Cx43cKO). To compare the developing skull phenotype between Cx43cKO mice and littermates in which the Cx43 gene is not floxed (Wnt1‐Cre2+/‐; mTmG+/+, herein Cx43WT), we will collect homologous landmark data from microCT images of newborn skulls and use geometric morphometric analyses to quantify and visualize shape differences in neural crest‐ and mesoderm‐derived portions of the skull between genotypes.To determine the localized effects of a neural‐crest specific loss of Cx43 function on osteoblast and chondrocyte differentiation, we will use immunofluorescence staining. Expression of chondrocyte, osteoblast, and osteocyte differentiation markers will be localized and semi‐quantitatively compared between genotypes and between neural crest‐ and mesoderm‐derived cells. With these assays, we aim to understand the relationship between Cx43, cNCC differentiation, and the subsequent impacts on skull morphology.Preliminary ResultsCx43cKO neonates show decreased ossification compared to Cx43WT littermates, which is most prominent in facial bones such as the nasal bones, and cranial vault bones such as the frontal and parietal bones. Potential driving forces for this decreased ossification in neural crest‐ and mesoderm‐derived bones are delayed differentiation of the osteoblast‐osteocyte lineage and disrupted signaling between cells in neighbouring bones.Significance &amp; Future DirectionsThis study will help elucidate the role of cNCC differentiation in skull development, and how loss of Cx43 function impacts skull development. We will add embryonic and post‐natal timepoints to further understand the impacts of neural crest‐specific deletion of Cx43 throughout development; pilot data with Cx43cKO adult mice show that alterations to skull shape persist and overtly affect the face and mandible.

Sex Determination in Japanese Quails (Coturnix japonica) Using Geometric Morphometrics of the Skull.

Simple SummaryThis study aims to determine the sexual dimorphism of quail’s skull by using the geometric morphometric morphometrics and to reveal the shape differences between male and female individuals. For these purposes, photographs of quail skulls in dorsal, ventral, and caudal views were taken and analyzed with the geometric morphometric method. The most significant difference in terms of sexual dimorphism was observed in the dorsal aspect. In caudal view, it was seen that the roof of the skull in females is thinner and longer than in males, but the sex distribution was not decisive compared to other aspects. Geometric morphometrics proved to be a good tool for analyses of the sexual dimorphism and better than traditional morphometrics by their potential way of shape analyses.The study investigated whether there is a morphological difference between the shape of the female and male quail’s skulls. For this purpose, 18 female and 21 male quails were used. After the skulls were obtained, their photographs were taken, and geometric analysis was performed. Dorsal (14 landmarks), caudal (8 landmarks), and ventral (13 landmarks) images of skulls were evaluated. As a result of the Principal Component Analysis (PCA), 28 principal components (PCs) were obtained for dorsal view, 16 PCs for caudal view, and 26 PCs for ventral view. PC1 (41.206%) for the caudal aspect explained the highest shape variation in terms of sex. It was seen that PC1 for dorsal view explained 33.046% and PC1 for ventral view explained 34.495% shape variation. For the dorsal view, the orbital pit of males was found to be deeper than females. The foramen magnum was narrower in female skulls. The lateral borders of the neurocranium were more pointed upwards in males. On ventral view, it was seen that male individuals had a wider skull in shape. Geometrically, it was determined that the male and female distinction was the best in the dorsal view. According to the dorsal view, only one male individual was found to be in the female group, and all other male individuals were completely separated from the females. After the dorsal view, the best distinction was seen ventrally. In the caudal examination, sexual discrimination was not fully seen. In this study, shape differences in quail’s skulls were examined between sexes, and shape differences were revealed geometrically. In addition to traditional morphometry studies, it is thought that geometric analysis studies will add a useful perspective to the literature.

Metadata Schema for Managing Digital Data and Images of Thai Human Skulls

This research was aimed at developing metadata that meets international standards for the purpose of managing digital data and images of Thai human skulls for medical studies. The research was conducted by applying the Metadata Lifecycle Model of the Metadata Architecture and Application Team. The model comprises four steps: requirement assessment and content analysis, identification of metadata requirements, metadata schema development, and metadata service and evaluation. The research outcome was a metadata schema composed of four modules, seven data element sets, and 29 pieces of data, each of which had six sets of property descriptions. Metadata evaluation conducted by three specialists in the field of anatomy and forensic medicine and three experts in the field of information science and metadata through free retrieval based on the Continuum of Metadata Quality in four aspects revealed that the experts were satisfied with the quality of metadata at a very high level: 100% for completeness, accuracy, and accessibility, and 94% for conformance to expectations. The developed metadata contain details that can be used to describe the characteristics of human skulls, with consideration taken in the development of the language used, retrieval, access, data exchange, and sharing. Thus, this novel metadata schema can be of use in management of digital data and images of human skulls for the purposes of medical studies, i.e., human anatomy and forensic anthropology.

Estimation of Forensic Sex Based on Three-Dimensional Reconstruction of Skull in Korean: Non-metric Study

This study performed the forensic anthropological sex estimation of Koreans in a non-metric way by reconstructing three-dimensional (3D) computed tomography (CT) images of skulls. The skull CT images used in this study were 100 (51 males, 49 females), and all CT images were taken with a slice thickness of 0.75 mm and then reconstructed into 3D images using the MIMICS 23.0 program. Using the reconstructed 3D image, measurements were repeated twice. The sex determination was male if the 4 point to 5 point was relatively more in five landmarks, and female if the points of 1 to 2 were relatively more. Results of the study show that, 88 of the 100 cases matched the actual sex. Among the 12 discrepant cases, ten cases were mismatched with the actual sex even though the estimation and repeated estimation readout of sexestimating were the same. Two cases, were “unknown,” showing different sexes in the first and repeated estimations. In conclusion, this study indicated that a forensic anthropological analysis from 3D images provided accurate point information on the landmarks of skulls, showing as high an accuracy as the sex estimation method using real bones. The ten cases of sex mismatch, except the two “Unknown” cases, are considered to be errors that did not consider differences in population groups. In further studies, further establishing a nonmetric, specifically Korean methods to increase the accuracy and reliability of sex estimation is need.

Facial skeleton morphology: does it reflect social stratification in an Early Mediaeval population from Great Moravia (ninth–tenth century AD, Czech Republic)?

This study examines the relationship between facial morphology and socioeconomic status within an Early Mediaeval population from the Mikulcice settlement. The agglomeration was the centre of the Great Moravian Empire in Central Europe and had a hierarchically structured society. The settlement can be divided on the basis of two criteria that possibly reflect socioeconomic classes: grave location (castle and sub-castle area) and grave goods (individuals with or without luxury grave goods). As study material, we utilized CT images of adult skulls. We divided the facial skeleton into two morphological regions: the upper face (49 males and 45 females) and the mandible (47 males and 41 females), which were investigated by landmark-based methods of geometric morphometrics. The results suggest that the population was highly stratified and that both of the criteria could reflect different genetic backgrounds, lifestyles or environmental conditions. Significant differences in upper face morphology were found between individuals with or without luxury grave goods, and significant differences in mandibular morphology between individuals buried in the castle and sub-castle areas. Although the morphology of the facial skeleton has a multi-etiological nature and all its parts are influenced by a complex of internal and external factors, upper face morphology based on grave goods may be more influenced by genetic variability between the study groups in the context of patrilocality and patrilineality, which were conventional practices in Early Mediaeval societies. On the other hand, mandibular morphology may be more influenced by external conditions (probably by a different diet).

Towards a Method for Discerning Sources of Supply within the Human Remains Trade via Patterns of Visual Dissimilarity and Computer Vision

While traders of human remains on Instagram will give some indication, their best estimate, or repeat hearsay, regarding the geographic origin or provenance of the remains, how can we assess the veracity of these claims when we cannot physically examine the remains? A novel image analysis using convolutional neural networks in a one-shot learning architecture with a triplet loss function is used to develop a range of ‘distances’ to known ‘reference’ images for a group of skulls with known provenances and a group of images of skulls from social media posts. Comparing the two groups enables us to predict a broad geographic ‘ancestry’ for any given skull depicted, using a mixture discriminant analysis, as well as a machine-learning model, on the image dissimilarity scores. It thus seems possible to assign, in broad strokes, that a particular skull has a particular geographic ancestry.

A Registration and Deep Learning Approach to Automated Landmark Detection for Geometric Morphometrics.

Geometric morphometrics is the statistical analysis of landmark-based shape variation and its covariation with other variables. Over the past two decades, the gold standard of landmark data acquisition has been manual detection by a single observer. This approach has proven accurate and reliable in small-scale investigations. However, big data initiatives are increasingly common in biology and morphometrics. This requires fast, automated, and standardized data collection. We combine techniques from image registration, geometric morphometrics, and deep learning to automate and optimize anatomical landmark detection. We test our method on high-resolution, micro-computed tomography images of adult mouse skulls. To ensure generalizability, we use a morphologically diverse sample and implement fundamentally different deformable registration algorithms. Compared to landmarks derived from conventional image registration workflows, our optimized landmark data show up to a 39.1% reduction in average coordinate error and a 36.7% reduction in total distribution error. In addition, our landmark optimization produces estimates of the sample mean shape and variance-covariance structure that are statistically indistinguishable from expert manual estimates. For biological imaging datasets and morphometric research questions, our approach can eliminate the time and subjectivity of manual landmark detection whilst retaining the biological integrity of these expert annotations.

Biological relationships and frontal sinus similarity in skeletal remains with known genealogical data.

Frontal sinus analysis has potential utility for detecting biologically related individuals. However, the methodological approach to its evaluation, as well as its informative value, have been questioned. The aim of this work is to introduce a new approach to evaluating the frontal sinus using the 'external supraorbital line' (ESOL) and to determine whether there are sex differences within families in frontal sinus measurements and whether frontal sinus similarity reflects known genetic relationships in both measurements and morphology. We examined the skeletal remains of 41 adult individuals (25 males, 16 females), all members of one family over four generations (19th to 20th centuries), including individuals with very close consanguinity. CT images of skulls were acquired, and both the dimensions and morphology of the frontal sinuses were analyzed using their portions above the ESOL. No significant sex differences were found within families based on frontal sinus dimensions. Significant relationships were found between biological distance and the maximum height and morphology of the frontal sinuses. The greatest degree of similarity was found among closely related individuals. Additionally, in several cases, there was a greater degree of similarity between first cousins or grandparents and their grandchildren than among siblings or parents and their children. Total surface, volume and width are not significant indicators of relatedness. Known genetic relationships are also supported by individual morphological features. Variability within families with very close consanguineous relationships was lower than within families with common degrees of consanguinity, although differences are significant only for some variables.

Sexual dimorphism of foramen magnum: An Egyptian study

BackgroundHuman identification is of a paramount forensic concern. It includes sex determination which becomes extremely complex and tricky especially in fragmentary remains.Purpose of the studyWe aimed to evaluate the accuracy of ten dimensions of foramen magnum (FM) and occipital condyles in determination of sex among 367 subjects (204 females and 163 males), their ages ranged between 18-75 years. Multislice Computed Tomography images of skulls of the studied patients were obtained from the Radiology Department. Ten different anatomical variables of the FM were measured by two independent experienced radiologists blinded to the study.ResultsFM dimensions are unique and show significant sexual dimorphism in the studied Egyptian population especially with application of discriminant function analysis. These landmarks include foramen magnum length and width (FML, FMW), FM index, FM area, length of the right and left occipital condyles (LROC, LLOC), width of the right occipital condyle (WROC), maximum bicondylar distance (MBD) and minimum intercondylar distance (MnICD). LROC and FMW are highly significant discriminating variables predicting sex.ConclusionsIt is concluded that all the studied FM parameters showed significant differences between males and females except the left occipital condylar width with higher male values when compared to females. Additionally, the right occipital condylar length and FM width are highly significant discriminating variables which are strongly beneficial in prediction of sex. FM dimensions would provide a reliable additional tool for identification of sex among adult population and could be specific for Egyptians in case of fragmentary remains or damaged skulls.

Інтерпретація постаті Якова І (VI) та образів довкола нього на гравюрі Джона Друзхаута «Король Яків І Англійський та VI Шотландський із Правдою і Часом, Пам’яттю та Історією» (1651)

This essay aimed at iconological analysis of an engraving by John Droeshout. During the study, the author applied classical methods of art history: iconological and iconographical, method of formal stylistic analysis of Heinrich Wölfflin, culture-historical method of Jacob Burkhardt. The engraving dates back to 1651 – by that time the King has been already dead. Thus, it allows to explore the commemorative and representative practices of his successors. Droeshout's engraving and poetic commentary testify that the language of visual arts was perceived as optional and ancillary; one that helps to understand the plot of the book better (visually). Droeshout tests the weakening of the concept of ‘the divine right of Kings’. The images of skulls, time and candles are typical allegories of memento mori and vanitas. These images function in two dimensions at once: 1) indicating that King dies in the same way as ordinary people do; 2) while connecting the anthropomorphic images of Time, Truth, History, Memory they also indicating the inevitable restoration of Truth, which Time will return to History with the help of Memory. The prospect of further research is the disclosure of interaction between the narrative and the image of James I, which functioned in the English society of the revolutionary period (1640-1689). At the same time the ‘visual language’ of the elements of engraving (the symbolism of windows next to the figures of Memory and History, rugs behind the King's figure) should be explored.

Convolutional Neural Network to Detect and Measure Fetal Skull Circumference in Ultrasound Imaging

In obstetrics, ultrasound is used for assessment of fetal development during pregnancy. The images generated by ultrasound are used to obtain measurements of fetal head length, body size, and the analysis of fetal movements, to identify and prevent the onset of congenital disease. This work presents the development of a new method for the segmentation of two-dimensional ultrasound images of fetal skulls based on a V-Net architecture called Fully Convolutional Neural Network - Combination (VNet-c). We created a new combination of strategies using a 3D V-Net as base, such as pre-processing, use of Batch Normalization and Dropout, and evaluation of distinct activation layers, activation function, data augmentation, loss function, and network depth. The computational results reveal the feasibility of the proposal in the correct segmentation of fetal skulls and head circumference measurements, reaching up to 97.91% of correctness, overcoming states-of-the-art methods.

Sex estimation from skull base radiographs in a contemporary Colombian population

The aim is to study the sexual dimorphism of the base of the skull in radiographs of a bone collection of contemporary Colombian adults, with the intention of formulating discriminant functions capable of classifying sex in this population. The sample consisted of 115 skull base radiographs, (44 females and 71 males), which originated from the Colombian Human Skeletals Collection. Radiographs with good contrast were selected. Images of skulls with asymmetries and fractures were excluded. Five measures: Maximum cranial base length, Foramen magnum length, Maximum cranial breadth, Bizygomatic breadth, Foramen magnum breadth length, were preformed using ImageJ5 software ®; an intra-observer error was determined using paired t-test. Statistical analysis showed a sexual dimorphism for all variables (p < 0.05). The step-by-step procedure of the discriminant function selected 2 variables from the 5 (Foramen magnum length and Bizygomatic breadth) and the precision was between 86.4% and 88.6% in the determination of sex. However cross-validation showed an accuracy of 85.7% to male and 87.2% to female. The skull base is highly dimorphic. The established discriminant functions can be used to estimate sex in the Colombian population.

Artificial intelligence for sex determination of skeletal remains: Application of a deep learning artificial neural network to human skulls

A deep learning artificial neural network was adapted to the task of sex determination of skeletal remains. The neural network was trained on images of 900 skulls virtually reconstructed from hospital CT scans. When tested on previously unseen images of skulls, the artificial neural network showed 95% accuracy at sex determination. Artificial intelligence methods require no significant expertise to implement once trained, are rapid to use, and have the potential to eliminate human bias from sex estimation of skeletal remains.

Ontogenia de las órbitas en Pan troglodytes: implicancias estructurales, funcionales y evolutivas

Las órbitas de los primates Haplorrhini son particulares dentro de los mamíferos por estar completamente separadas de la fenestra temporal y rodeadas por hueso, ser convergentes, estar frontalizadas y proveer la base para el desarrollo de un notorio torus supraorbitario. Estas características han sido descriptas, algunas como adaptaciones al hábito de vida y otras como resultado de reacomodaciones estructurales de las matrices funcionales del cráneo. El objetivo de este trabajo es analizar los cambios morfológicos de las órbitas en una muestra ontogenética transversal de Pan troglodytes y su asociación con estructuras adyacentes a fin de discutir implicancias estructurales y funcionales. Se utilizaron 52 imágenes de tomografías computadas de cráneos de Pan troglodytes desde 8 meses de vida postnatal hasta adultos. Se registraron landmarks y se tomaron medidas volumétricas y lineales que permitieron extraer variables angulares y proporciones. Se realizó ANOVA, regresiones lineales y parciales y Análisis de Componentes Principales. Los resultados indican que los rasgos de valor adaptativo (funcionales) de la órbita de Pan troglodytes se establecen tempranamente en la ontogenia y no varían durante el período postnatal, mientras que su relación con estructuras adyacentes muestra importantes cambios.

Determination of reference values for normal cranial morphology by using mid-sagittal vector analysis in Japanese children

Mid-Sagittal Vector Analysis (MSVA) is a method of measuring the distance from a defined central point on the skull surface in the entire mid-sagittal plane and provides a clear description of the lateral view of the skull. We used a series of images of normal skulls of Japanese children to determine normal MSVA values. For this cross-sectional study, we first constructed a database of head CT and MRI images of children aged 0-6 years (41.5 ± 24.9 month (mean ± SD)) who showed no abnormality of cranial development and growth at the time of imaging. Measurement errors due to lateral shifting of the sagittal plane during MSVA were examined, CT and MRI images taken in the same patients at the same time were compared, and measurement differences were examined. Finally, MSVA was carried out, and the mean of the measured values was calculated according to age group. Two hundred ninety-five images were included in the database. When the lateral shifting of the sagittal plane was within 4 mm from the true mid-sagittal plane, the mean errors were less than 1 mm at all measurement points. Between the CT and MRI images from the same patients, most differences in MSVA values were within ±1 mm. These differences were thus acceptable for use in clinical settings. After the above verifications, 220 images were extracted for determination of normal MSVA values. We established a normal dataset of MSVA for Japanese children that can be used effectively for preoperative diagnosis, surgery planning, and postoperative assessment of cranial deformities.