Canonical Variate Analysis Research Articles

Wing geometric morphometrics for identification of mosquito species (Diptera: Culicidae) of neglected epidemiological importance

Culicidae comprises more than 3500 species, some of which are responsible for the spread of various human diseases, causing millions of deaths worldwide. Correct identification of these species is essential for the development of surveillance and control strategies. The most common method of mosquito identification is based on specific traits of the external morphology of species. However, identification of mosquitoes by morphological characters can be inaccurate or even unfeasible if the specimen is damaged or there is a lack of distinguishing features, as in the case of cryptic species complexes. Wing geometric morphometrics is a reliable, affordable tool for the identification of mosquito species, including sibling species. More importantly, it can be used in addition to both traditional morphologic identification methods as well as genetic approaches. Here, wing geometric morphometrics was used to identify sixteen mosquito species from eight genera: Aedes, Coquillettidia, Culex, Limatus, Mansonia, Psorophora, Runchomyia, and Wyeomyia. The 390 specimens used here were collected in São Paulo, Brazil using CDC traps, aspiration, and Shannon traps. Allometry was assessed by multivariate regression of the Procrustes coordinates on centroid size followed by canonical variate analysis and a pairwise cross-validated reclassification test. A Neighbor-Joining tree based on Mahalanobis distances was constructed with 1,000 bootstrap replicates using MorphoJ 1.02 and Past 2.17c. The canonical variate analysis of genera resulted in distinct clusters for Culex, Limatus, and Psorophora and partial overlapping between Aedes, Coquilettidia, and Mansonia, and between Runchomyia and Wyeomyia. Pairwise cross-validated reclassification tests indicated that genera were identified with an accuracy of at least 99% and subgenera with a mean accuracy of 96% and that in 160 of the 240 possible comparisons species were identified with an accuracy of 100%. Our results show that the eight genera in the study were correctly distinguished by wing shape, as were subgenera and most species, demonstrating that wing geometric morphometrics can be used for the identification of the mosquito species studied here.

A Kernel Design Approach to Improve Kernel Subspace Identification

Subspace identification methods, such as canonical variate analysis (CVA), are noniterative tools suitable for the state-space modeling of multi-input, multi-output processes, e.g., industrial processes, using input-output data. To learn nonlinear system behavior, kernel subspace techniques are commonly used. However, the issue of kernel design must be given more attention because the type of kernel can influence the kind of nonlinearities that the model can capture. In this article, a new kernel design is proposed for CVA-based identification, which is a mixture of a global and local kernel to enhance generalization ability and includes a mechanism to vary the influence of each process variable into the model response. During validation, model hyper-parameters were tuned using random search. The overall method is called feature-relevant mixed kernel CVA (FR-MKCVA). Using an evaporator case study, the trained FR-MKCVA models show a better fit to observed data than those of single-kernel CVA, linear CVA, and neural net models under both interpolation and extrapolation scenarios. This work provides a basis for future exploration of deep and diverse kernel designs for system identification.

The Use of Macro, Micro, and Trace Elemental Profiles to Differentiate Commercial Single Vineyard Pinot noir Wines at a Sub-Regional Level.

The compositional authentication of wine is of great interest, as the geographic origin of the grapes is often associated with quality, uniqueness, and authenticity. Previous elemental fingerprinting studies mainly discriminated wines from different countries or regions within a country. Here, we report the use of element profiles to distinguish commercial Pinot noir wines from five sub-regional appellations or neighborhoods within one American viticultural area (AVA). Fifty-three single cultivar wines were collected over two harvests and analyzed using microwave plasma-atomic emission spectroscopy (MP-AES) and inductively coupled plasma-mass spectrometry (ICP-MS). Of 62 monitored elements that were quantified with fully validated methods, 24 and 32 elements differed significantly across the neighborhoods and vintages, respectively (p < 0.05). Targeted canonical variate analysis (CVA) explained 85–90% of the variance ratio across the two vintages, indicating persistent and stable elemental fingerprints of wines at a sub-regional level. A sixth, newly founded neighborhood was correctly grouped separately from the others using a Soft Independent Modeling of Class Analogy (SIMCA), indicating the potential of elemental fingerprints for wine authenticity.

Simulating multispectral MSI bandsets (Sentinel-2) from hyperspectral observations via spectroradiometer for identifying soybean cultivars

Monitoring soybean areas by remote sensing is extremely useful, especially in Brazil, which has a large territorial extension and where soybean cultivation has spread to all regions of the country. In this sense, the development of remote sensing techniques that enable the quantification and discrimination of soybean areas and now in cultivated cultivar level is of crucial importance for the soybean production chain in Brazil. This study aimed to discriminate soybean cultivars as a function of different hyperspectral bands using the sensor-system MSI-Sentinel-2 (Vis-NIR-SWIR) as a simulation and sample sizes using multivariate statistics to determine if the specific bands of this sensor are capable of performing such discrimination. Four soybean cultivation areas in the Midwest region cultivated with four cultivars (BMX Potência, NA5909, Don Mario, and FT Campo Mourão) were assessed. Spectral readings from each sample soybean leaf were performed, and a total of 2400 vegetation spectral readings were obtained. Data were composed of 28 bands and 22 reflectance factor height (RID) values for each soybean cultivar. Multivariate statistical analysis was performed to verify the association between soybean cultivars and their relationship with hyperspectral bands, as well as to verify the possibility of cultivar differentiation based on hyperspectral bands. The results obtained demonstrated to be possible discriminate soybean cultivars by using multivariate techniques applied to multi and hyperspectral data. The bands that contributed significantly (>5%) to cultivar differentiation in order of importance were: B26, B27, A17, A21, A20 and A14. Discriminant analysis was efficient in the cultivar classification, and canonical variable analysis revealed bands associated with specific discrimination of each cultivar. Bands that most contributed to cultivar discrimination were also identified for MSI orbital sensor.

Unraveling the systematics and evolution of the ‘Geophagus’ brasiliensis (Cichliformes: Cichlidae) species complex

The ‘Geophagus’ brasiliensis complex is one of the most abundant groups of cichlids from eastern coastal basins in South America. Traditionally, this fish group has been recognized as incertae sedis because of phylogenetic uncertainties and unclear taxonomy. In addition, the remarkable morphological, chromosomal, and DNA variation reported over recent years in several populations of these cichlids has increased the debate about their species richness and their distributional range. Here, we tested the presence of independent evolutionary lineages within the ‘G.’ brasiliensis complex, addressing their taxonomic status and evolutionary relationships, including a comparative analysis of genetic and morphological patterns, based on an extensive dataset, comprising 172 sampling sites along most of their known range using a mitochondrial marker, RADseq data and geometric morphometrics. The number of putative species in the present study varied from 9 to 11 depending on the molecular species delimitation methods used. Our results revealed at least two putative new taxa (‘Geophagus’ sp. Doce and ‘Geophagus’ sp. Upper Contas). Morphometric analyses, particularly those based on Canonical Variate Analysis (CVA), revealed significant morphological differentiation between species within the main clades. On the other hand, analyses of morphological phylogenetic signal and phylomorphospace provided no evidence of adaptive differentiation among these species. Thus, diversification in the ‘G.’ brasiliensis complex seems to have been influenced by hydrogeological events that promoted allopatry, such as the presence of paleodrainages and distributional reconfiguration through river captures. We propose major changes in the known distribution of some species within the complex and conservatively suggest the recognition of 10 species within the ‘Geophagus’ brasiliensis complex, with the potential for further dividing ‘G.’ rufomarginatus after additional taxonomic evaluation.

Life after the mother's hug: Late post-embryonic development of Cryptops parisi (Chilopoda: Scolopendromorpha: Cryptopidae)

Here we describe in detail the late post-embryonic development of the common European scolopendromorph centipede Cryptops parisi. Canonical variate analyses of two groups of external morphological characters, viz., cephalic capsule characters (head length, length of the anterior and posterior paramedian cephalic sutures) and coxopleuron surface characters (number of pores in the coxal pore-field, number of setae on the posterior coxopleuron edge, their number on the coxal pore-field, and their number posterior to the coxal pore-field) were conducted on a large sample of specimens collected from two localities in Serbia. Ten free-living stages are recognized: three pre-adult stages (adolescens I, II, and III) and seven adult stages (one maturus junior stage, four maturus, and two maturus senior stages). The fourth late post-embryonic stage is the first mature stage in both sexes. Sexual dimorphism in the aforementioned characters was not observed. Morphological variation of coxopleuron characters was more informative for the discrimination of developmental stages in Cryptops than the morphological variation of cephalic capsule characters.

Pilot Study of Quantitative Methods for Differentiating Pharyngeal Swallowing Mechanics by Dysphagia Etiology.

Quantitative analysis of modified barium swallow (MBS) imaging is useful to determine the impact of various disease states on pharyngeal swallowing mechanics. In this retrospective proof of concept study, kinematic analysis and computational analysis of swallowing mechanics (CASM) were used to demonstrate how these methods differentiate swallowing dysfunction by dysphagia etiology. Ten subjects were randomly selected from four cohorts of dysphagic patients including COPD, head and neck cancer (HNC), motor neuron disease, and stroke. Each subject was age- and gender-matched with healthy, non-dysphagic controls. MBS videos of 5ml thin and 5ml thick bolus trials from each subject were used. A MATLAB tracker tool was adapted and updated to collect and compile data for each video (n = 160). For kinematic measurements, a MANOVA was performed with post-hoc analyses to determine group differences. For CASM measurements, a morphometric canonical variate analysis with post hoc analysis was performed to determine group differences. Kinematic analyses indicated statistically significant differences between HNC cohort and controls in distance measurements forhyolaryngeal approximation (p = .001), laryngeal elevation (p = 0.0001), pharyngeal shortening (p = 0.0002), and stage transition duration timing (p = 0.002). Timing differences were noted between the stroke cohort and controlsforpharyngeal transit time (p = 0.007). Multivariate morphometric canonical variate analysis showed significant differences between etiology groups (p < 0.0001) with eigenvectors indicating differing patterns of swallowing mechanics. This study demonstrated that swallowing mechanics among cohorts of dysphagic patients can be differentiated using kinematics and CASM, providing different but complementary quantitative methods for investigating the impact of various disease states on swallowing function.

Morphological study of Sudanonautes africanus (Miline-Edwards, 1869) in three freshwater bodies of Ondo State, Nigeria.

Freshwater crabs are a cheap and important source of animal protein for human beings. They also serve as bio-indicators of ecosystem disruption and also conservation icons. Despite their importance, there are still some unresolved issues in their phylogenies. This study aimed to examine the morphological variations in freshwater crab, S. africanus from three different water bodies in South-west, Nigeria. Thirty samples were collected from each of the study locations morphological study using morphometrics and meristics characters. Morphometrics characters did not show variations in species of crabs, unlike meristic that showed variations in the episternum and abdominal segments of S. africanus. The study also revealed that the crabs exhibit a negative allometric growth (b<3). The condition factor revealed that the crabs are healthy (K>1). Cluster diagram of the Canonical Variate analyses of the morphological parameters showed that there are no variations in the morphological characteristics of S. africanus. Cluster diagram of the meristic characters shows that there are little variations in the meristic characters of S. africanus in the three study locations.

A Comparative Study of the Data-Driven Stochastic Subspace Methods for Health Monitoring of Structures: A Bridge Case Study

Subspace system identification is a class of methods to estimate state-space model based on low rank characteristic of a system. State-space-based subspace system identification is the dominant subspace method for system identification in health monitoring of the civil structures. The weight matrices of canonical variate analysis (CVA), principle component (PC), and unweighted principle component (UPC), are used in stochastic subspace identification (SSI) to reduce the complexity and optimize the prediction in identification process. However, researches on evaluation and comparison of weight matrices’ performance are very limited. This study provides a detailed analysis on the effect of different weight matrices on robustness, accuracy, and computation efficiency. Two case studies including a lumped mass system and the response dataset of the Alamosa Canyon Bridge are used in this study. The results demonstrated that UPC algorithm had better performance compared to two other algorithms. It can be concluded that though dimensionality reduction in PC and CVA lingered the computation time, it has yielded an improved modal identification in PC.

Assessment of Shape Variation Patterns in Triatoma infestans (Klug 1834) (Hemiptera: Reduviidae: Triatominae): A First Report in Populations from Bolivia.

The morphological variations of four populations of geographically isolated Triatoma infestans located in the area of inter-Andean valleys and Chaco of Chuquisaca, Bolivia, were evaluated. Fifty-three females and sixty-one males were collected in the peri-domicile and analyzed with geometric morphometrics tools to study the patterns of the head and wing shape variation. The principal component analysis and canonical variate analysis revealed morphological variations between the populations studied, which were then confirmed by the permutation test of the differences between populations using Mahalanobis and Procustes distances. The multivariate regression analysis shows that the centroid size influences the shape of the heads and wings. T. infestans of the inter-Andean valleys are longer in the head and wings compared to the population of the Chaco. We propose that the geometric shape variation may be explained by geographical changes in climatic conditions, peri-domiciliar habitats, food source quality, and the use of insecticides.

Size matters: micro-evolution in Polynesian rats highlights body size changes as initial stage in evolution.

Microevolutionary patterns in populations of introduced rodent species have often been the focus of analytic studies for their potential relevance to understanding vertebrate evolution. The Polynesian rat (Rattus exulans) is an excellent proxy species because of its wide geographic and temporal distribution: its native and introduced combined range spans half the globe and it has been living for at least seven centuries wherever it was introduced. The objective of this study was to assess the effects of long-term isolation (insularity; up to 4,000 years) and geographic variables on skull shape variation using geometric morphometrics. A sample of 513 specimens from 103 islands and four mainland areas was analysed. This study, to my knowledge the first to extensively sample introduced rats, analysed 59 two-dimensional landmarks on the skull. Landmarks were obtained in three separate aspects (dorsal, lateral, ventral skull view). The coordinate data were then subjected to a multivariate ordination analysis (principal components analysis, or PCA), multivariate regressions, and a canonical variates analysis (CVA). Three measures of disparity were evaluated for each view. The results show that introduced Polynesian rats evolve skull shapes that conform to the general mammalian interspecific pattern of cranial evolutionary allometry (CREA), with proportionally longer snouts in larger specimens. In addition, larger skulls are more tubular in shape than the smaller skulls, which are more balloon-shaped with a rounder and wider braincase relative to those of large skulls. This difference is also observed between the sexes (sexual dimorphism), due to the slightly larger average male size. Large, tubular skulls with long snouts are typical for Polynesia and Remote Oceania, where no native mammals occur. The greater disparity of Polynesian rats on mammal species-poor islands (’exulans-only’ region) provides further insight into how diversity may affect diversification through ecological release from predators and competitors.

Low-Rank Characteristic and Temporal Correlation Analytics for Incipient Industrial Fault Detection With Missing Data

In real industrial applications, process data may get corrupted due to failure of the measurement devices or errors in data management. Besides, incipient faults, which may evolve into serious accidents, are generally more difficult to be detected because of its small magnitudes. In this article, a robust canonical variate dissimilarity analysis method is proposed to detect incipient faults for industrial processes with missing value. According to the low-rank characteristic, the low-rank matrix decomposition (LRMD) method is applied to recover the missing elements and reduce the ambient noise for process data. The output results of LRMD model consist of a low-rank component and a sparse component, which indicate main variance and residual information of the inputted data, respectively. For each component, a canonical variate analysis) model is developed to extract the temporal correlation in the process data. Based on the obtained features, a total of three monitoring statistics are established to reflect the operation status of the online sample. Among them, a statistic is used to measure the static deviation of this sample, and other two indices are applied to evaluate the dissimilarity between the past and future canonical variates. A simulated process and a real industrial process are adopted to illustrate the performance of the proposed method. Experimental results show that the proposed model can be well developed with incomplete training data and robustly detects the incipient faults for industrial applications.

Capelin Mallotus villosus population differentiation among and within regions using relative warps

Arctic and sub-Arctic ecosystems are rapidly changing, but morphological diversity can increase a species’ resilience to these environmental fluctuations. Capelin Mallotus villosus is a cold-water forage fish distributed throughout the northern hemisphere, but is not thoroughly studied outside the Atlantic Ocean, which impedes our ability to infer the functional significance of morphometric variation among populations. The objective of this study was to use relative warps, a comprehensive geometric morphometric method, to determine if capelin populations could be distinguished by beach spawning location in the western Canadian Arctic (one location), Newfoundland, Canada (three locations), and Alaska, USA (two locations). Morphometry was examined separately by sex and compared among and within geographic regions using relative warp analysis (RWA), Procrustes ANOVA, estimates of morphological disparity, and canonical variates analysis (CVA). For both sexes, capelin from the western Canadian Arctic were differentiated from other regions, primarily by pelvic fin location. Within Newfoundland, capelin from Witless Bay, Bellevue Beach (males only), and Middle Cove were only distinguishable from each other using CVA. Within Alaska, males from Norton Sound were distinct from Prince William Sound using RWA and CVA. When all subregions were examined together, evidence for population separation was weaker for both sexes than when regions or subregions were examined separately. These morphological variations imply diversity throughout this species’ geographic distribution. Biological attributes (e.g., total length, weight, fecundity), which are influenced by multiple environmental factors such as prey availability, also varied among and within regions and may explain some of the identified morphometric diversity.

Multivariate morphometric investigation to delineate species diversity and stock structure of mud crab Scylla sp. along the coastal regions of Bangladesh

Despite the importance of mud crab species (genus Scylla) in both coastal aquaculture and artisanal fisheries, knowledge of the species diversity and stock structure of mud crab population for their sustainable management across the coastal region of Bangladesh remains obscure. Therefore, the present study was conducted to delineate the diversity and stock structure of mud crab species based on the 24 morphometric length measurements and 27 morphometric ratios data collected from the three coastal regions (Chittagong, Cox's Bazar and Bagerhat) of Bangladesh. Based on the taxonomic keys, majority of the species (about 82.4%) were identified as S. olivacea, while the remaining (about 17.6%) was S. serrata. In consistent to our preliminary analysis, both the univariate proportion and multivariate analysis of the collected morphometric lengths and ratios data also distinctly divided the mud crabs population into two multivariate spaces as S. serrata and S. olivacea. For the further analysis of the stock structure of these two species, data were subjected to the univariate ANOVA, multivariate ANOVA, Canonical Variate Analysis (CVA), and Principal Component Analysis (PCA) according to their collection sites. Scatter plots of CVA scores between CV1 and CV2 and PCA scores between PC1 and PC2 showed that the individuals of both species clearly made clusters into three multivariate spaces with minimum overlaps according to their collection sites. In morphometric traits Linear Discriminant Function Analysis (LDFA), the average percentage of correctly classified (PCC) into the original groups of the S. olivacea and S. serrata was 100%. For stock discrimination, the average PCC into their original groups of collection sites were 100% and 99% for the S. olivacea and S. serrata, respectively. Finally, dendrogram based on the Euclidean distances consistently separated S. olivacea and S. serrata and stock structures similar to other multivariate analyses. In conclusion, our study shows that S. olivacea is the dominant mud crab species and S. serrata is the minor one, and the stock discrimination of each species should be considered in the management and conservation policy of these species along the coastal region of Bangladesh.

Is the scapula a good indicator of taxonomy?: A geometric morphometric analysis using macaque monkeys

In primates, scapular shape is often thought to correlate to locomotor patterns with distinct morphologies observed in arboreal versus terrestrial species. However, the extent to which intra‐generic morphological differences might be related to taxonomic differences as opposed to convergent locomotor behaviors remains to be tested. Thus, we tested the hypothesis that closely related, but behaviorally distinct, species may exhibit variation in their scapular morphology that match known phylogenetic relationships among the specious macaque monkey. Our sample (n=230) represented nine species; M. fascicularis, M. mulatta, M. fuscata, M. arctoides, M. radiata, M. nigra, M. nemestrina, and M. sylvanus and a Colobine outgroup (Trachypithecus cristatus). 3D scans of the left scapula were taken using an HDI structured light scanner and 5 landmarks and 61 sliding semilandmarks were applied to the scans to capture overall form. Following Procrustes superimposition, Canonical Variates Analysis (CVA) was performed and Procrustes coordinates were extracted and used for a Discriminant Function Analysis (DFA). The results of the CVA showed clear differences between Trachypithecus and macaques, as well as between M. fuscata and M. radiata and all other macaques. In the cross‐validated DFA, only 34.1% of individuals were correctly classified. The outgroup Trachypithecus showed a correct classification rate of 70%, as did M. nigra consistent with relatively distinct morphology in this taxon. Overall, patterns of morphological variation observed in the CVA do not match phylogenetic history, therefore suggesting environmental factors might influence the pattern of morphological variation among macaque species in novel ways, though this remains to be tested.Support or Funding InformationThis research is supported by a National Science Foundation Grant (NSF BCS‐1830745), Field Museum Visiting Researcher Fellowship, Primate Research Institute Cooperative Research Grant, University at Buffalo Asian Studies Grant, and the Mark Diamond Research Fund (SP‐18‐13).

Analyzing Facial Asymmetry in Children as a Function of BMI

Childhood obesity is a major public health concern in the US with a prevalence of nearly 19% for all children and adolescents. During growth, environmental factors such as poor diet can result in increased developmental stress. Given the symmetric patterning of facial growth in humans, any random deviations from symmetry, referred to as fluctuating asymmetry (FA), are considered a reflection of stress during growth. In this study, we examine whether childhood obesity serves as a source of developmental stress resulting in increased facial asymmetry. We hypothesize that a significant relationship between facial asymmetry and BMI exists, with higher BMI individuals demonstrating increased levels of facial asymmetry.To test our hypothesis, we obtained n=354 3D facial scans of children (age 3–19) from the University of Pittsburgh Center for Craniofacial and Dental Genetics. A total of n=286 facial scans represented children with a normal weight and n=68 faces were from children with obesity. Obesity status was determined using BMI values at or above the 95th percentile. Facial scans were digitized using 34 coordinate landmarks to capture asymmetry in the eyes, nose, mouth, and lower jaw. Coordinate data was submitted to a Generalized Procrustes Analysis (GPA) to align the facial landmarks and geometric morphometrics (GM) was then employed to quantify facial shape phenotypes in MorphoJ. Principal Component Analysis (PCA) was used to identify patterns of facial asymmetry throughout the entire sample. Canonical Variate Analysis (CVA) was then employed to identify differences in facial shape due to BMI. Lastly, a Procrustes ANOVA was ran to quantify levels of fluctuating asymmetry in the sample and the resulting FA scores were regressed against BMI percentile to test for a significant relationship.The results from the PCA identified 43 principal components (PCs), with the first three PCs accounting for 44.3% of total facial asymmetry. PC1 (accounting for 20.6% of facial asymmetry) identified asymmetry in the position of the eyes and a slight deviation of the nose, mouth and lower jaw to the left or right. PC2 (12.9%) demonstrated asymmetry primarily between the jaw and nose. PC3 (10.7%) further illustrated asymmetries through the eyes and jaw. The results of the CVA showed a significant difference (p=0.023) in overall asymmetry between normal weight children with children with obesity. Normal weight children demonstrated a trend toward facial symmetry while obese children showed marked asymmetry with respect to the eyes, nose, and chin. Finally, the results of the regression between FA scores and BMI percentile did not produce any significant association (p=0.72).While these results indicate a significant difference in the patterning of facial asymmetry between normal and obese children, evidence for increased FA levels (and therefore developmental instability) was not observed. Although we reject our hypothesis, the results demonstrate interesting facial asymmetries between BMI groups that may be promising for future analysis with longitudinal data.Support or Funding InformationGrant support: R01‐DE016148

Facial Asymmetry Increases as a Function of Age

Humans, like all bilaterian organisms, follow a symmetric body plan during growth and development. Deviations from symmetry during growth arise as a function of developmental instability caused by biological and environmental stressors such as poor diet and illness. Fluctuating asymmetry (FA) refers to random left/right asymmetries and is considered a quantifiable proxy for developmental stress. This study will investigate the patterning of facial asymmetry in a large population to highlight aspects of facial asymmetry within and between age groups. We also quantify FA across the sample to test the hypothesis that facial asymmetry increases as a function of age.To determine whether levels of facial asymmetry vary with age, a cross‐sectional sample of n=900 facial scans representing four age groups (child: 3–10 y/o, adolescent: 11–18 y/o, young adult: 19–27 y/o, and older adult: 28–40 y/o) from the University of Pittsburgh Center for Craniofacial and Dental Genetics 3D Facial Norms study were analyzed. 34 landmarks were captured along facial structures including the eyes, nose, mouth, and chin, superimposed using Generalized Procrustes Analysis (GPA), and analyzed using geometric morphometrics (GM) in MorphoJ. Following GPA, the asymmetric component of facial shape was examined using both Principal Components Analysis (PCA) and Canonical Variate Analysis (CVA) to evaluate patterns of overall facial asymmetry and whether or not different facial asymmetry patterns exist between age groups. Finally, a Procrustes ANOVA was employed to calculate a fluctuating asymmetry (FA) score for each individual and scores were regressed against age to test whether facial asymmetry increases with age.PCA results identified 43 principal components (PCs), of which the first three components accounted for nearly 42% of the overall facial asymmetric shape variation. PC1 confirmed that 19.7% of the asymmetries occurred in eye position, accounting for the largest aspect of facial asymmetry in the combined sample. PC2 and PC3, accounting for 12.8% and 9.4% of the asymmetric shape variation respectively, occurred mostly in the lower face and jaw line. Results from CVA found significant differences (p&lt;0.02) in facial asymmetry between the age groups. CV1, accounting for 84% of the variation between groups identified asymmetries predominantly in the eyes and nose. CV2 (11.7% variation) demonstrated asymmetries of chin and lower face while CV3 (4.3%) indicated variations in asymmetry of the jaw line. Lastly, results from the Procrustes ANOVA confirmed a significant positive relationship between age and fluctuating asymmetry (p=0.0002, r2=0.014).This study identifies key aspects of facial asymmetry that exist between younger and older age groups, particularly increased asymmetries in the lower face of the adult groups compared to the younger age groups. Additionally, fluctuating asymmetry does increase slightly as a function of age, confirming our hypothesis. Future research will focus on specific factors that relate to these facial asymmetries, such as poor diet, using both cross‐sectional and longitudinal populations.Support or Funding InformationR01‐DE016148

Variants in the Hippo Signaling Pathway are Associated with Craniofacial Skeletal Form and BMI

Childhood obesity rates in the United States have demonstrated a marked increase since the late 20th century. Current research has suggested that obesity can cause increases in bone density and an acceleration of skeletal growth. While studies have shown that obesity may be associated with altered craniofacial form, the mechanism and associated factors through which this interaction operates remains poorly understood. This study explores a potential link between obesity and craniofacial skeletal form as a function of the Hippo signaling pathway, an important regulator of organ size, tissue development, and craniofacial development.Lateral cephalograms from a sample of n=64 patients between the ages 7 to 17 were obtained from the Midwestern University Multispecialty Clinic. BMI percentile was computed for all children in the study following CDC guidelines (normal weight n=37, overweight n=9, obese n=18). 45 2D landmarks were registered via Generalized Procrustes Analysis (GPA) in order to facilitate a geometric morphometric (GM) analysis. Healthy Eating Index (HEI) scores obtained from Block Food Frequency Questionnaire (FFQ) surveys were used to control for the effects of diet in all subsequent analyses. Shape residuals were submitted to Principal Components Analysis (PCA) and Canonical Variate Analysis (CVA) to identify which aspects of skeletal form differentiate individual phenotypes based on BMI. Finally, associations between these phenotypes and 23 single nucleotide polymorphisms (SNPs) in seven genes within the Hippo signaling pathway were explored.Principal Components (PCs) accounting for at least 1% of facial shape variation were examined in order to determine components that differentiate between normal and obese groups. Based on this, suggestive/significant differences were found in PC 8 (p=0.056) and PC12 (p=0.012) based on BMI category. PC 8 (accounting for 3.6% of the total shape variation) indicates that chin projection, nose length, and mandibular morphology differentiate between normal and obese children. SNPs in TEAD3 (p=0.04) and FAT4 (p = 0.02) were significantly associated with shape variation along PC8. PC 12 (2.6% of the total shape variation) showed significant variation in chin projection and decreased incisor size in the obese group relative to the normal weight group. Additionally, a SNP within LATS2 (p = 0.04) was significantly correlated with shape variation along PC12. Finally, results from the CVA identified two components with CV2 indicating a significant relationship with LEF1 (p= 0.02). CV2 demonstrates increased facial projection in individuals with obesity.Across all analyses, we found a consistent pattern in mandibular length, facial projection, and incisor size that differentiated between normal and obese individuals. SNPs within key genes in the Hippo signaling pathway were associated with these phenotypes, indicating a potential causative relationship. Future studies will explore this relationship further.

Variation in Maxillary Sinus Anatomy: Implications of Ostium Positioning on Health Disparities in Sinusitis

Over 30 million people are diagnosed with sinusitis annually, yet potential anatomical etiologies behind sinus infections remain poorly understood. Paranasal sinus drainage is mediated by mucociliary transport and gravity, but the human orthograde posture and superior positioning of the maxillary sinus (MS) ostia increase reliance on the mucociliary system. Moreover, previous research has suggested that regional differences in MS size and shape may contribute to disparities in sinusitis susceptibility. The purpose of this study was to examine overall MS size and shape, including MS ostium positioning, among three different ancestral groups, to assess potential impacts on drainage and infection risks. Employing CT scans (n=167) of crania from European, East Asian, and Equatorial African ancestries, we collected 28 3D coordinate landmarks per specimen. A total of 34 linear measurements of the MS and surrounding facial features were subsequently calculated and employed in multivariate analyses. MANOVA test results reveal significant differences between regional groups (Wilk’s λ = 0.807, p &lt; 0.0001) and between the sexes (Wilk’s λ = 0.813, p &lt; 0.0001), but no significant interaction between region and sex (Wilk’s λ = 0.971, p = 0.3223). ANOVA and Tukey‐Kramer test results indicate that Asians have both a significantly taller MS (F=15.4, p&lt;0.0001) and a significantly greater distance from the MS floor to the ostium (F=13.5, p&lt;0.0001) compared to Europeans and Africans. Further, a ratio of these two linear variables reveals that the MS floor‐to‐ostium distance constitutes a greater percentage of overall MS height in Asians (62%) than Europeans (60%) or Africans (59%). A canonical variate (CV) analysis of the 28 3D coordinate landmarks provides corroborative results, with CV1 accounting for 70.58% of total variance and separating Asians from Europeans and Africans. Morphologically, CV1 predominantly reflects a lower MS floor in Asians, while the relative superior‐inferior position of the MS ostium within the face appears similar across all ancestries. Cumulatively, these results suggest that both the taller sinus and greater MS floor‐to‐ostium distance in Asians are attributable to a more inferiorly positioned MS floor. As a greater distance from the MS floor to the ostium may lead to increased pressure on the mucociliary clearance, our results suggest that individuals of Asian ancestry may be at a greater risk for chronic sinusitis compared to those of European and African ancestries. Our study thus provides tentative evidence that there may be an anatomical etiology for chronic sinusitis despite an absence of anatomical defect. The increased risk for persistent inflammatory condition is also important since it has been accompanied with subsequent head and neck cancer diagnoses. Additional research into the prevalence of MS sinusitis in these populations is warranted to evaluate possible contributions to health disparities.Support or Funding InformationThis work is partially supported by a grant funded to Dr. Jamboor Vishwanatha by the Cancer Prevention and Research Institute of Texas (Award #: RP170301).

The Size and Shape of the Alveolar Process: A Morphometric Analysis of the Dental Arch During Fetal and Infantile Development

The development of the alveolar process is closely tied to numerous oral pathologies, including cleft lip and cleft palate. Despite the importance of the alveolar process, little gross anatomical study has been performed with regard to its development. Therefore, this study analyzed 187 dry maxillae from 109 individuals aged from five‐months intrauterine to five‐months post‐natal. Distances between the centers of the five alveoli were measured via photogrammetry. Interalveolar distances and age (months development) were utilized to develop best‐fit regression equations. Paired‐samples t‐tests were performed between left‐ and right‐sided interalveolar distances. Also, geometric morphometric analysis was performed and included canonical variate analysis to identify shape change among different age groups and between‐block partial least squares analysis to assess covariation in the premaxillary alveolar process and alveolar process of the maxilla proper. The interalveolar parameter most closely related to age was that of the intermolar distance (Distance = [−0.02962(age2)] + [0.8854 (age)] + 0.7475; r2=0.5983). Additionally, three out of four inter‐alveolar distances in addition to the total length of the dental arch significantly differed between the left and right sides (p=0.0003, p=0.0027, p &lt;0.0001, p=0.0078, respectively). Alveolar arch shape was significantly different among most age groups; this was especially the case when there was a greater difference in age (i.e., early intrauterine vs late post‐natal). Furthermore, PLS analysis demonstrated a strong relationship between the shapes of the premaxilla and maxilla proper (Correlation coefficients of PLS1 and PLS2 were 0.73 and 0.70, respectively). The results of this study improve the understanding of alveolar process growth― age is best estimated by intermolar distance (and vice‐versa), there is asymmetry between left‐ and right‐sided maxilla growth, dental arch shape changes with age, and the shape of the premaxilla is closely related to the shape of the maxilla proper.Support or Funding InformationFunding: WV Research Challenge Fund [HEPC.dsr.17.06]