Analysis Of Linear Measurements Research Articles

Morphometric analysis of the palatal shape and arch dimension in subjects with buccally displaced canine.

To analyse morphological variations of the palate shape and maxillary arch dimension between a group of subjects with unilaterally or bilaterally buccally impacted maxillary canines and a control group (CG) by means of 3D geometric morphometric (GMM). Pre-treatment records of 50 subjects (16 males and 34 females; mean age 13.9 years ± 1.8) with one or both canines buccally displaced were collected retrospectively. A CG of 50 subjects was selected from a list of orthodontic patients at the same dental hospital. The experimental group, buccally displaced canine (BDC) was divided in two groups: unilateral buccally displaced canine (UBDC) and bilateral buccally displaced canine (BBDC). To analyse the palate's shape and maxillary arch dimension, study casts were scanned. To study the entirety of the palatal shape, 3D GMM analysis was used. To analyse the maxillary arch dimension, the virtual three-dimensional models were measured with a specific software (VAM, Vectra, Canfield Scientific, Fairfield, New Jersey, USA). When comparing the groups with the GMM analysis, patients with BDC showed a statistically significant narrower and higher palatal vault. About the analysis of linear measurements, the intercanine width, the anterior and posterior segment length were significantly smaller in BDC, UBDC, and BBDC subjects when compared with the controls and there were no differences between UBDC versus BBDC groups. Patients with buccally displaced permanent canine tended to have maxillary transverse constriction and variation in palatal vault morphology. The morphometric variation of the palatine vault and arch dimensions can be considered a clinical factor associated with the presence of BDC.

Assessment of the upper respiratory tract in patients eligible for treatment with transverse maxillary expansion

Transverse maxillary hypoplasia may negatively affect respiration. Maxillary narrowing has to be treated early. An appliance for Rapid Maxillary Expansion (RME) is the most common method, and it aims to expand the skeletal base and maintain this width until a new bone has been formed to fill in the fissure. Aim. Comparison of the results of measurements of bone structures and of the upper airways on lateral teleroentgenograms of the head in patients with transverse maxillary hypoplasia and in patients with normal dimensions of the maxilla. Material and methods. The study was carried out in a group of 20 people with maxillary narrowing (10 girls and 10 boys) aged 7 to 10 years. The control group consisted of 20 lateral teleroentgenograms of patients (9 girls and 11 boys) of similar age treated for other malocclusions. The structures of the facial skeleton and the upper respiratory tract were assessed in teleroentgenograms after earlier determination of measurement points and planes according to selected parameters of the McNamara and Preston et al. methodology. The obtained results were analysed statistically using the Mann-Whitney's test. Results. Angular measurements showed statistically significantly smaller SNA and SNB angles in the study group compared to the control group. The analysis of linear measurements indicated a statistically significant larger dimension of the actual length of the midfacial segment (Co-A) and distance between the Sella point and the posterior nasal spine (PNS-S), and a smaller dimension of the posterior facial height (PFH) in the study group compared to the control group. The highest differences in upper respiratory tract measurements were noted in the Ba-ho-PNS angle, which was lower in the study group. The result was not statistically significant. Conclusions. No significant differences in cephalometric measurements of the upper airways were observed. There is a need to extend studies to include groups of patients with features of night apnoea and maxillary narrowing. <b>(Dargiewicz E, Szarmach IJ, Sawczuk M. Assessment of the upper respiratory tract in patients eligible for treatment with transverse maxillary expansion. Orthod Forum 2018; 14: 97-105)</b>

Sex Variations by Linear Measurements of Palatal Bones and Skull Base Using 3D Reconstructed Computed Tomographic Scan among Iraqi Sample

Background: The skull base and the hard palate contain many anatomical features that make them rich in information which are useful in sex differentiation; in addition to that they have the ability to resist the hardest environmental conditions that support them in making sex differentiation. Three dimensional computed tomographic techniques has important role in differentiation between sex since it offers images with very accurate data and details of all anatomical structures with high resolution. This study was made to study sex variations among Iraqi sample by craniometric linear measurements of the hard palate and the skull base using 3D reconstructed Computed Tomographic scan. Materials and methods: This study composed of 100 Iraqi subjects (50 male and 50 female) aged between 20-59 years. The sample collected from patients attending Al-Shaheed Ghazi hospital in Baghdad city to for spiral CT scanner. The craniometrical linear measurements of the hard palate and the skull base in this study were including: Maxillo-Alveolar Breadth, Maxillo-Alveolar Length, the distance between incisive foramen and greater palatine foramen (right and left), the distance between the incisor foramen and B point (the median point located at the anterior area of the magnum foramen), the distance between the incisor foramen and the anterior root of the mastoid notch on both sides (right and left), Maxillo-Alveolar Index and size of Palate. All these measurements were done by (mm) unit. Results: The statistical analysis of linear measurements of the hard palate and the skull base showed that the mean values of all measurements were significantly higher in males than females except for Maxillo-Alveolar Index was not significant and also showed that the size of the palate was the best indicator for sex variation and making the diagnosis of male with accuracy 93.3%. The age had none significant effect on these measurements. Conclusion: Three dimensional Computed Tomographic scanners is the best diagnostic tool for sex variation by the craniometrical linear measurements for the anatomical landmarks points of the hard palate and the skull base.

Analysis of linear measurements on 3D surface models using CBCT data segmentation obtained by automatic standard pre-set thresholds in two segmentation software programs: an in vitro study.

The aim of this in vitro study was to evaluate the reliability and accuracy of linear measurements on three-dimensional (3D) surface models obtained by standard pre-set thresholds in two segmentation software programs. Ten mandibles with 17 silica markers were scanned for 0.3-mm voxels in the i-CAT Classic (Imaging Sciences International, Hatfield, PA, USA). Twenty linear measurements were carried out by two observers two times on the 3D surface models: the Dolphin Imaging 11.5 (Dolphin Imaging & Management Solutions, Chatsworth, CA, USA), using two filters(Translucent and Solid-1), and in the InVesalius 3.0.0 (Centre for Information Technology Renato Archer, Campinas, SP, Brazil). The physical measurements were made by another observer two times using a digital caliper on the dry mandibles. Excellent intra- and inter-observer reliability for the markers, physical measurements, and 3D surface models were found (intra-class correlation coefficient (ICC) and Pearson's r ≥ 0.91). The linear measurements on 3D surface models by Dolphin and InVesalius software programs were accurate (Dolphin Solid-1 > InVesalius > Dolphin Translucent). The highest absolute and percentage errors were obtained for the variable R1-R1 (1.37 mm) and MF-AC (2.53 %) in the Dolphin Translucent and InVesalius software, respectively. Linear measurements on 3D surface models obtained by standard pre-set thresholds in the Dolphin and InVesalius software programs are reliable and accurate compared with physical measurements. Studies that evaluate the reliability and accuracy of the 3D models are necessary to ensure error predictability and to establish diagnosis, treatment plan, and prognosis in a more realistic way.

A revision of the rare genusCyclolampas(Echinoidea) using morphometrics with description of a new species from the upper Callovian of Burgundy (France)

The discovery of a new species,Cyclolampas altusnew species in the upper Callovian of Burgundy (France) leads to the systematic revision of the rare echinoid genusCyclolampasPomel, 1883. Two morphometric approaches are used jointly to describe and quantify variations in test shape: the analysis of linear measurements and the Elliptic Fourier shape analysis. Both analyses yield congruent results that highlight the amplitude of within-species variations and quantify the part due to allometry. Along with the description ofC. altus, the systematic position of species formerly assigned to the generaPygorhytisPomel, 1883 andCyclolampasis amended. Previously attributed to the genusPygorhytis,Cyclolampas castanea(Desor, 1858) is reassigned to the genusCyclolampason the base of new observations. Conversely, the examination of the Bajocian speciesPygorhytis kiliani(Lambert, 1909) andPygorhytis gillieroniDesor in Desor and de Loriol, 1872, which were previously assigned toCyclolampasnow supports their taxonomic reassignment to the genusPygorhytis. Finally, the two speciesCyclolampas verneuili(Cotteau, 1870) andCyclolampas cotteauiMintz, 1966 (nomen nudum) are considered junior synonyms of the genus type speciesCyclolampas voltzii(Agassiz, 1839). The questioned origin date of the genus, estimated either to the Bajocian or to the Oxfordian, is now clearly established to be upper Callovian. These new results fit well with the overall scheme of atelostomate echinoid evolution and migration to deep-sea environments during the Middle and Upper Jurassic.

Differentiating sibling species in the Quaternary fossil record: a comparison of morphological and molecular methods to identify Microtus arvalis and M. rossiaemeridionalis (Arvicolinae, Rodenia)

The sibling species Microtus arvalis and Microtus rossiaemeridionalis are widely sympatric, North Eurasian species that are difficult to trace back in the fossil record due to the lack of criteria for taxonomic identification. This paper examines the potential of morphometric and molecular methods for differentiating their fossil remains. Discriminant function (DF) analysis of linear measurements of the lower first molar (m1) is used to create and validate a predictive model for taxonomic identification using modern M. arvalis (obscurus karyotypic form) and M. rossiaemeridionalis from the Ural Mountains. For modern specimens both the derived DF and the molecular methods yielded identical results for species identification. DF derived from modern data was applied to m1s of M. arvalis sensu lato from Subatlanticum (1300–1200 BP) and Atlanticum (7380 ± 150 BP) layers of the Pershinskaya 1 cave in the Middle Urals. In addition, from 27 mandibles with m1 in the morphological dataset 258 bp of cytochrome b were sequenced using ancient DNA techniques. Comparison of the morphological and molecular results revealed a substantial loss of predictive power of the DF derived from modern data when applied to fossils. Morphological change since the mid Holocene appears detrimental to DF derived from recent data. Our results emphasize the need for verification of taxonomic inferences from morphological data when dealing with sibling species, and accentuate the advantages of joint use of morphological and molecular methods in differentiating cryptic taxa in the fossil record.

Description of a digital cranial endocast of Bathygenys reevesi (Merycoidodontidae; Oreodontoidea) and implications for apomorphy-based diagnosis of isolated, natural endocasts

ABSTRACT Relatively few studies of cranial endocasts document intraspecific variation. Here, discrete morphological and morphometric variation from a sample of more than 150 natural cranial endocasts from a single Eocene locality, Reeves Bonebed (hereafter ‘RBB’) from West Texas are documented. The first description of a digital endocast of an oreodont, Bathygenys reevesi, is given to provide comparative data for other oreodont endocasts. The RBB endocasts were originally assigned to B. reevesi, but virtually none has diagnostic craniodental material still attached, and isolated endocasts of other cetartiodactyl species are known from this locality. Consequently, an attempt was made to identify apomorphies on the RBB sample to diagnose specimens to the lowest possible taxonomic level. The RBB endocasts were diagnosed as oreodonts based on the presence of large, rounded casts of the tuberculum olfactorium, but no specimen can be diagnosed to a particular species. The range for most linear measurements for the RBB sample overlapped with measures from multiple species of oreodonts from RBB. A coefficient of variation analysis of linear measurements suggests that the RBB sample represents more than one species. Therefore, endocasts from RBB that lack associated craniodental material cannot be definitively assigned to a species, and the original assumption that all are B. reevesi is not supported. This illustrates the necessity of applying apomorphy-based identifications for isolated specimens, including endocasts. In addition, this study reveals some gaps in data from cetartiodactyl brains, which need to be filled for future studies on brain evolution in this clade.

Análise multivariada das medidas morfométricas de potros da raça Mangalarga Marchador: análise de componentes principais

Objetivou-se, com este trabalho, a avaliação morfométrica de potros da raça Mangalarga Marchador, a partir da análise de componentes principais. As medidas corporais foram efetuadas na semana do nascimento dos potros, em 55 potros e 41 potras; aos seis meses de idade, em 35 potros e 37 potras; e aos 12 meses de idade, em 19 potros e 31 potras. Foram efetuadas 25 mensurações lineares, envolvendo altura, comprimento, largura e perímetros, e 11 mensurações angulares. Na avaliação dos animais com 12 meses de idade, foram consideradas apenas 19 medidas lineares, além das 11 angulares. Nas potras e potros recém-nascidos, a análise reduziu o número de medidas lineares de 25 para 7 e 9, respectivamente, enquanto nas medidas angulares, a redução foi de 11 para 6 e 7, nas potras e potros, respectivamente. Nas potras e potros com seis meses de idade, observou-se decréscimo no número de medidas lineares de 25 para 8 e 9, respectivamente, enquanto nas medidas angulares, a redução foi de 11 para 6, em ambos os sexos. Nas potras e potros com 12 meses de idade, a redução das medidas lineares foi de 19 para 6 e 5, respectivamente, enquanto nas medidas angulares, de 11 para 6 e 5, nas potras e potros, respectivamente. A análise dos componentes principais foi eficiente em reduzir o número de medidas lineares e angulares necessárias para a avaliação morfométrica de potros, sendo a redução maior entre as medidas lineares do que entre as angulares, entretanto, os dois primeiros componentes principais, nas diferentes idades estudadas, não conseguiram explicar 80% da variação total disponível, o que impossibilitou a interpretação em um plano bidimensional.

THE HEAD-BODY RATIO IN HUMAN FIGURE DRAWINGS OF SCHIZOPHRENIC AND NORMAL ADULTS.

Abstract Human figure drawings produced by a group of chronic schizophrenic women were compared to those produced by a group of normal adult women for head-body ratio. Support was sought for the theory that the body portion of the body image disintegrates as a function of psychosis and that this disintegration is projected into human figure drawings. The schizophrenic group produced drawings in which the head was significantly more predominate as determined by statistical analysis of linear measures. The results offer support for the body image theory of disintegration in psychosis and for the clinician's assumption that detectable distortions arising from certain psychological states are projected into drawings of the human figure.

A study of relative growth in UCA pugnax.

1. 50 males and 43 females were divided into classes according to carapace breadth. The relative growth rates of certain parts of the body were investigated by analysis of linear measurements carried out on the carapace and appendages. 2. The increased growth rate of pereiopods immediately posterior to the strongly heterogonic cheliped was concluded to be due, in part at all events, to the rapid growth of the cheliped, since the increase is considerably smaller on the small cheliped side in the male. 3. There seems to be, in addition, a sexual difference, the growth in the corresponding pereiopods in the female differing from that found in the male on the small cheliped side. 4. In the female the growth of the last two pereiopods is greater than that in the male; it is suggested that this is possibly due to the influence of the region of rapid growth present in the abdomen in the female. 5. The appendages anterior to the large cheliped in the male are apparently not inhibited. In this respect Uca pugnax differs from other forms which have been investigated. 6. The growth rate of the carapace breadth is greater than that of its length throughout the period investigated in the male, but only throughout the earlier part of the development of the female.