Methodological Proposal for the Adequate Use of the Osteotechnics Technique / Propuesta Metodológica para el uso Adecuado de la Técnica Osteotécnica

SUMMARY: Osteotechnics is one of the different anatomical preservation techniques and can be defined as the technique designed to prepare, clean, obtain and preserve bone structures that can be used in the teaching, museographic or research field. The osteotechnical technique procedure consists of the following phases: debulk and disjoint, maceration, cooking, cleaning, degreasing, bleaching, and labeling to obtain bone material. Seven phases will be explained in detail, as well as the materials, instruments, quantities of the substances used, and the time required to obtain human bone material. We consider that this article can serve as a guide, given that all the experimentation was carried out with human biological material. This methodological proposal could be consolidated and established based on the experience acquired during the creation of the contemporary skeletal collection of the department of innovation in human biological material (DIMBIH). Therefore, the purpose of our proposal is to provide tools that facilitate the work of those who carry out this work and fundamentally to avoid irreversible or irreparable damage to the osteological material, since it is of great value and difficult to acquire for disciplines as anatomy, veterinary, physical and forensic anthropology, medicine, dentistry and biology.

La osteotecnia es una de las técnicas diferentes de conservación anatómica y puede definirse como la técnica destinada a preparar, limpiar, obtener y conservar estructuras óseas que pueden ser utilizadas en el ámbito docente, museográfico o de investigación. El procedimiento de la técnica osteotécnica consta de las siguientes fases: descarnado y desarticulado, maceración, cocción, limpieza, desengrase, blanqueo y marcaje para la obtención de material óseo. Se explicarán en detalle siete fases, así como los materiales, instrumentos, cantidades de las sustancias utilizadas y el tiempo necesario para obtener material óseo humano. Consideramos que este artículo puede servir de guía, dado que toda la experimentación se realizó con material biológico humano. Esta propuesta metodológica pudo consolidarse y establecerse a partir de la experiencia adquirida durante la creación de la colección esquelética contemporánea del Departamento de Innovación en Material Biológico Humano (DIMBIH). Por lo tanto, el propósito de nuestra propuesta es brindar herramientas que faciliten el trabajo de quienes realizan este trabajo y fundamentalmente evitar daños irreversibles o irreparables en el material osteológico, ya que es de gran valor y difícil adquisición para las disciplinas como la anatomía, veterinaria, antropología física y forense, medicina, odontología y biología.

Estudios de corte transversal: un diseño de investigación a considerar en ciencias morfológicas / Cross section studies: a research design to consider in morphological sciences

Los estudios de corte transversal (ECT) inician en la década de los 40 en países Europeos. Los ECT corresponden a investigaciones de tipo observacional que permiten estudiar prevalencia de enfermedad, determinar asociación entre variables y el desarrollo de un efecto de interés, conocer propiedades de una prueba diagnóstica, y censar poblaciones; describiendo las características de una población en un momento y lugar determinado. Esto implica, que no se requieren periodos de seguimiento, que no son prospectivos ni retrospectivos; características que permiten que sean más baratos y fáciles de realizar en relación a los estudios longitudinales. Por otro lado, al ser de carácter descriptivo sirven como insumo y evidencia preliminar para estudios de mayor complejidad metodológica, como estudios de cohortes. Sin embargo, tienen limitantes y sesgos que deben ser considerados por los investigadores. El objetivo de este manuscrito fue generar un documento de estudio para revisar características esenciales, fortalezas y debilidades; discutir cuestiones metodológicas de los ECT en ciencias de la salud; y proporcionar algunos ejemplos obtenidos de la literatura, para mejor comprensión del diseño.

SUMMARY: Cross-sectional studies (CSS) began European countries in the 1940s in. The CSSs correspond to observational-type investigations that allow studying the prevalence of disease, determining the association between variables and the development of an effect of interest, discovering the properties of a diagnostic test, and censusing populations, describing the characteristics of a population at a given time and place. This implies that follow-up periods are not required, and that they are neither prospective nor retrospective. These characteristics allow them to be cheaper and easier to perform in relation to longitudinal studies. On the other hand, being descriptive in nature, they serve as input and preliminary evidence for studies of greater methodological complexity, such as cohort studies. However, they have limitations and biases that must be considered by researchers. The aim of this manuscript was to generate a study document to review essential characteristics, strengths and weaknesses; discuss methodological issues of ECT in health sciences; and provide some examples obtained from the literature, for a better understanding of the design.

Automated morphological phenotyping using learned shape descriptors and functional maps: A novel approach to geometric morphometrics.

The methods of geometric morphometrics are commonly used to quantify morphology in a broad range of biological sciences. The application of these methods to large datasets is constrained by manual landmark placement limiting the number of landmarks and introducing observer bias. To move the field forward, we need to automate morphological phenotyping in ways that capture comprehensive representations of morphological variation with minimal observer bias. Here, we present Morphological Variation Quantifier (morphVQ), a shape analysis pipeline for quantifying, analyzing, and exploring shape variation in the functional domain. morphVQ uses descriptor learning to estimate the functional correspondence between whole triangular meshes in lieu of landmark configurations. With functional maps between pairs of specimens in a dataset we can analyze and explore shape variation. morphVQ uses Consistent ZoomOut refinement to improve these functional maps and produce a new representation of shape variation, area-based and conformal (angular) latent shape space differences (LSSDs). We compare this new representation of shape variation to shape variables obtained via manual digitization and auto3DGM, an existing approach to automated morphological phenotyping. We find that LSSDs compare favorably to modern 3DGM and auto3DGM while being more computationally efficient. By characterizing whole surfaces, our method incorporates more morphological detail in shape analysis. We can classify known biological groupings, such as Genus affiliation with comparable accuracy. The shape spaces produced by our method are similar to those produced by modern 3DGM and to auto3DGM, and distinctiveness functions derived from LSSDs show us how shape variation differs between groups. morphVQ can capture shape in an automated fashion while avoiding the limitations of manually digitized landmarks, and thus represents a novel and computationally efficient addition to the geometric morphometrics toolkit.

Con la antorcha entre la niebla de la vía aérea única: marcha atópica y otros argumentos en la búsqueda de la evidencia / With the Torch in the Mist of the United Airway Disease: Atopic March and Other Arguments in the Search for Evidence

No disponible

[Translated article] With the Torch in the Mist of the United Airway Disease: Atopic March and Other Arguments in the Search for Evidence / Con la antorcha entre la niebla de la vía aérea única: marcha atópica y otros argumentos en la búsqueda de la evidencia

No disponible

Eficacia del uso de claves de color en ilustraciones para el aprendizaje de la relación entre estructura y función en un curso de anatomía / Efficacy of using color keys in illustrations for learning the relation structure and function in an anatomy course

Introducción: La enseñanza de la anatomía humana ha hecho uso de diversas estrategias en la formación médica. Frente al surgimiento de nuevos métodos de enseñanza, planteamos un sistema de ilustraciones basado en claves de color que resaltan y simplifican la relación entre estructura y función. Asimismo, comparamos su eficacia frente a otros sistemas tradicionales. Sujetos y métodos: Ejecutamos un estudio experimental en estudiantes de pregrado de Medicina, asignados aleatoriamente en tres grupos que recibieron clases teóricas y prácticas, y material de texto para el aprendizaje de tópicos seleccionados de anatomía del miembro superior. El grupo ‘control’ no recibió material adicional, el grupo ‘tradicional’ recibió ilustraciones de alto realismo y a color y el grupo ‘colores’ recibió ilustraciones que hicieron uso de claves de color para la relación entre estructura y función. Los estudiantes fueron evaluados de forma teórica a través de una evaluación ad hoc y sometidos a una evaluación práctica a través del reconocimiento de estructuras cadavéricas. Los resultados se expresaron como media y desviación estándar. Resultados: En el estudio participaron 82 estudiantes distribuidos en tres grupos. No hubo diferencias en cuanto a edad y sexo. Las calificaciones de la evaluación teórica fueron mayores en el tercil medio de los estudiantes del grupo ‘colores’, 57,8% (5,8%), comparados con el grupo ‘tradicional’, 43,5% (3,9%). No existieron diferencias significativas en la evaluación práctica. Conclusión: El uso de claves de color en las ilustraciones tuvo una eficacia superior en un subgrupo de estudiantes cuando fue comparado con otro tipo de material (ilustraciones de alto realismo) para el aprendizaje de anatomía.(AU)

Introduction: The teaching of human anatomy has made use of various strategies in medical training. Faced with the emergence of new teaching methods, we propose a system of illustrations based on color codes that highlight and simplify the relationship between structure and function. Likewise, we compare its effectiveness against other traditional systems. Subjects and methods: We carried out an experimental study in undergraduate medical students, randomly assigned into three groups that received theoretical and practical classes, and text material for learning selected topics of upper limb anatomy. The ‘control’ group received no additional material, the ‘traditional’ group received highly realistic and colored illustrations, and the ‘colors’ group received illustrations that made use of color keys for the relationship between structure and function. The students were evaluated theoretically through an ad-hoc evaluation, and subjected to a practical evaluation, through the recognition of cadaveric structures. The results were expressed as mean and standard deviation. Results: 82 students participated in the study, divided into three groups. There were no differences regarding age and sex. The theoretical evaluation scores were higher in the middle tertile of the students in the ‘colors’ group: 57.8% (5.8%) compared to the ‘traditional’ group: 43.5% (3.9%). There were no significant differences in the practical evaluation. Conclusion: The use of color codes in illustrations was more effective in a subgroup of students when it was compared to other types of material (highly realistic illustrations) for learning anatomy.(AU)

Visualization of gross anatomy for ultrasound scanning planes using a virtual dissection table / Visualización de la anatomía macroscópica para planos de escaneo de ultrasonido utilizando una mesa de disección virtual

SUMMARY: There is a lack of visualization on gross anatomy planes for the non-orthogonal sections, such as subcostal and intercostal oblique scanning planes of ultrasound imaging. The aim of the present study was to visualize the anatomical image of corresponding plane for the oblique ultrasound scanning using a virtual dissection system. the oblique gross anatomy plane was constructed by appropriate segmentation using a virtual dissection table. A suitable cutting of the body plane was accomplished by turning on and off the organ systems, particularly the skeletal system, category, and structure. The right hepatic vein (RHV), middle hepatic vein (MHV), and left hepatic vein (LHV) for the right subcostal oblique plane appeared in the single slice plane. The location of the liver, gallbladder, and kidneys differently appeared in the oblique anatomical plane and body position. The results of this study suggest that using a virtual anatomy system contributes to improving the sonographer's ability to understand anatomy.

RESUMEN: Existe una falta de visualización en los planos de anatomía macroscópica para las secciones no ortogonales, tal como los planos de exploración oblicuos subcostales e intercostales en las imágenes de ultrasonido. El objetivo del presente estudio fue visualizar la imagen anatómica del plano correspondiente para la ecografía oblicua mediante un sistema de disección virtual. El plano de anatomía macroscópica oblicua se construyó mediante una adecuada segmentación utilizando una mesa de disección virtual. Se logró un corte correcto del plano corporal al encender y apagar los sistemas de órganos, particularmente el sistema esquelético, la categoría y la estructura. La vena hepática derecha, la vena hepática media y la vena hepática izquierda para el plano oblicuo subcostal derecho aparecieron en el plano de corte único. La ubicación del hígado, la vesícula biliar y los riñones aparecieron de manera diferente en el plano anatómico oblicuo y en la posición del cuerpo. Los resultados de este estudio sugieren que el uso de un sistema de anatomía virtual ayuda a mejorar la capacidad del ecografista para comprender la anatomía humana.

El Dr. Nicolás Triantafilo Klotza, los inicios de la Universidad de Antofagasta y la inmigración griega en el norte de Chile / Dr. Nicolás Triantafilo Klotza, the beginnings of the University of Antofagasta and Greek immigration in northern Chile

La Anatomía Humana en la Universidad de Chile, sede Antofagasta, fue el cimiento esencial para dar inicio a la carrera de medicina en 1971, como consecuencia de la Reforma Universitaria, creando las sedes Regionales de la Universidad. Un grupo de médicos-profesores, hijos de familias europeas, de los Balcanes, dictaban las clases en las aulas de ciencias de la salud en varias carreras de esta sede. En la década del 50, se suma a este grupo el médicocirujano Nicolás Triantafilo-Klotza (1922-2008), de ascendencia helénica, quien comienza organizando la asignatura de Patología para luego asumir la Cátedra de Anatomía Humana, siendo su titular hasta el año 1973, formando la "Unidad de Anatomía Humana". La Anatomía Humana era impartida en el anfiteatro del Hospital Regional "Leonardo Guzmán", para todas las carreras de la Salud y algunas carreras del área de Ciencias Sociales. Con la reforma universitaria de los 80 se descentraliza la educación superior estatal chilena, creándose las universidades regionales con autonomía propia. Esto generaría la Universidad de Antofagasta, entre otras, fruto de la fusión, decretada el 10 de marzo de 1981, de la UTE y la Universidad de Chile. La sede que ambas tenían en Antofagasta se transformó en la Universidad de Antofagasta, tal como la conocemos hoy. La carrera de medicina de la Universidad de Antofagasta renace en 1995.

Human Anatomy at the University of Chile, in Antofagasta, was the essential foundation for the beginning of the medical career in 1971, as consequence of the University Reform, creating the Regional branches of the University. A doctors-teachers group, descendent of European families, of the Balkans, were teaching health sciences in various courses at the University. In the 50's, the physician-surgeon Nicolás TriantafiloKlotza (1922-2008), of Greek descent, joined the group. He began organizing the Pathology course and later assumed the Chair of Human Anatomy, being its holder until 1973, forming the "Human Anatomy Unit". Human Anatomy taught in the amphitheater of the Regional Hospital "Leonardo Guzman", for all the careers of Health and some careers in the area of Social Sciences. With the university reform of the 80s, the Chilean state higher education was decentralized, creating regional universities with their own autonomy. This would generate the Universidad de Antofagasta, among others, as result of the merger, decreed on March 10, 1981, of the UTE and the Universidad de Chile. Both headquarters in Antofagasta was transformed into the Universidad de Antofagasta, as we know today. The medical career of the University of Antofagasta was reborn in 1995.

Communication, collaboration and contagion: "Virtualisation" of anatomy during COVID-19.

COVID-19 has generated a global need for technologies that enable communication, collaboration, education and scientific discourse whilst maintaining physical distance. University closures due to COVID-19 and physical distancing measures disrupt academic activities that previously occurred face-to-face. Restrictions placed on universities due to COVID-19 have precluded most conventional forms of education, assessment, research and scientific discourse. Anatomists now require valid, robust and easy-to-use communication tools to facilitate remote teaching, learning and research. Recent advances in communication, video conferencing and digital technologies may facilitate continuity of teaching and research activities. Examples include highly-interactive video conferencing technology, collaborative tools, social media and networking platforms. In this narrative review, we examine the utility of these technologies in supporting effective communication and professional activities of anatomists during COVID-19 and after.

Morfometría geométrica y sus nuevas aplicaciones en ecología y biología evolutiva: Parte 2 / Geometric morphometric and its new applications in ecology and evolutionary biology: Part 2

RESUMEN: La presente revisión entrega una visión actualizada del estudio de la morfometría geométrica y sus aplicaciones más actuales en ecología y biología evolutiva, metodología con una amplia variación en los últimos 5 años de su primera versión en International Journal of Morphology. La Morfometría geométrica es una herramienta que permite evaluar las variaciones morfológicas con factores subyacentes, siendo una herramienta más sensible que la morfometría tradicional, lo que permite detectar mínimos cambios de variación morfológica. Lo que la ha vuelto una herramienta notable para responder preguntas de biología comparada centradas en caracteres anatómicos. En sus comienzos fue una herramienta usada principalmente para responder preguntas taxonómicas, y para diferenciar a nivel de individuos, poblaciones o especies. No obstante, en los últimos años la cantidad de preguntas y problemáticas en las que se aplica, ha diversificado considerablemente, pasando a ser una herramienta muy precisa para responder preguntas de variación morfológica en contextos ecológicos y evolutivos. Ya ha pasado casi media década desde la última revisión del método, por lo que éste trabajo tiene como objetivo analizar los cambios metodológicos y los nuevos enfoques usados en Morfometría geométrica, y presentar una pequeña guía introductoria a éstos nuevos métodos, sus usos y aplicaciones.

SUMMARY: This study provides an updated vision of the study of Geometric Morphometrics and its most recent application in ecology and evolutionary biology, covering a wide variation in methodology occurring in the last 5 years since the first version published in the International Journal of Morphology. Geometric Morphometrics is a tool that allows evaluating morphological variations with underlying factors, with a higher sensitivity than traditional morphology, so that minimum changes of morphological variation can be detected. Therefore, it has turned into an outstanding tool to answer questions of comparative biology focused on anatomic characters. At the beginning, it was a tool mainly used to answer taxonomic questions and for differentiation at individual, population or species level. However, in the last years, the number of questions and problematic on which it is applied, has diversified considerably, turning it into a very accurate tool to answer questions of morphological variation in ecologic and evolutionary contexts. Almost half a decade has elapsed since the last revision of the method, so this work is intended to analyze the methodological changes and the new approaches used in Geometric Morphometrics, including a brief introductory guideline to these new methods, their uses and applications.

Micro-CT scan with virtual dissection of left ventricle is a non-destructive, reproducible alternative to dissection and weighing for left ventricular size.

Micro-CT scan images enhanced by iodine staining provide high-resolution visualisation of soft tissues in laboratory mice. We have compared Micro-CT scan-derived left ventricular (LV) mass with dissection and weighing. Ex-vivo micro-CT scan images of the mouse hearts were obtained following staining by iodine. The LV was segmented and its volume was assessed using a semi-automated method by Drishti software. The left ventricle was then dissected in the laboratory and its actual weight was measured and compared against the estimated results. LV mass was calculated multiplying its estimated volume and myocardial specific gravity. Thirty-five iodine-stained post-natal mouse hearts were studied. Mice were of either sex and 68 to 352 days old (median age 202 days with interquartile range 103 to 245 days) at the time of sacrifice. Samples were from 20 genetically diverse strains. Median mouse body weight was 29 g with interquartile range 24 to 34 g. Left Ventricular weights ranged from 40.0 to 116.7 mg. The segmented LV mass estimated from micro-CT scan and directly measured dissected LV mass were strongly correlated (R2 = 0. 97). Segmented LV mass derived from Micro-CT images was very similar to the physically dissected LV mass (mean difference = 0.09 mg; 95% confidence interval - 3.29 mg to 3.1 mg). Micro-CT scanning provides a non-destructive, efficient and accurate visualisation tool for anatomical analysis of animal heart models of human cardiovascular conditions. Iodine-stained soft tissue imaging empowers researchers to perform qualitative and quantitative assessment of the cardiac structures with preservation of the samples for future histological analysis.

Anatomía segmentaria del recto. Nuevo enfoque / Anatomy segmentation of the rectal. New approach

RESUMEN Se actualizó la clasificación anatómica del tumor de recto, con la revisión de varios tratados sobre anatomía. El estudio de la morfología interna del recto reconoce la formación de anchos pliegues. La formación de anchos pliegues de mucosas transversales, denominadas válvulas: una válvula inferior a 7 cm del ano, otra a 2 cm. Más arriba con una forma de media luna y la tercera a 11 cm del ano. Como estas válvulas son pliegues mucosos sin localización precisa no pueden ser consideradas como puntos anatómicos para segmentación del recto. De esta manera, la segmentación rectal como el límite entre recto superior e inferior se sitúa en la reflexión peritoneal; en el diagnóstico de tumores rectales la definición de su situación anatómica es importante para la conducta terapéutica, ya que el recto inferior tiene su origen embriológico en el proctodeo (ectoblástica) y puede ser más sensible a las radiaciones y los tumores del recto superior son tumores que se originan de tejido de formación entoblástica, las radiaciones producen lesiones del peritoneo y de otros órganos de la cavidad pelviana. La segmentación rectal es importante para el estadio locorregional del tumor y para la definición de un esquema de tratamiento adecuado. En primer lugar, establece el concepto anatómico de localización de un tumor de recto inferior, se diagnóstica con un tacto rectal, si es tocable es del recto inferior. En segundo lugar, define cuáles son los estudios complementarios para saber el estadio de la enfermedad y establece los parámetros anatómicos necesarios para la indicación del tratamiento neoadyuvante (AU).

SUMMARY To present a recent an anatomic classification of rectal tumor localization. Review of many anatomy treaties. The rectal internal morphology studies recognize the formation of thick folds of transversal mucosa thick folds named valves: a low valve to 7 cm from anus. Another is to 2 cm upper with a half moon form, a third one to 11 cm from anus. As this valves are mucosal folds without a clear localization they can't be consider as anatomical points to the rectum segment. Therefore, the rectal segmentation as the limit between up and low rectum, is located in the peritoneal reflection. In the rectal tumors diagnosis definition of it's anatomic situation is important for the therapeutic behavior, because the low rectum has its embryologic origin in the Proctodeum (ectoblastic). It can be more sensitive to the radiation the up rectum tumors are originated from the formation entoblast tissue (endoblast) the radiations cause peritoneal injuries and other pelvic cavity organs. The rectal segmentation is important for the locate-regional tumor stadium and for the appropriate treatment definition. In first place, establish the anatomic concept of the low rectal tumor localization. In second place defines which are the complementary for the new adjuvant indication (AU).

Virtual Anatomy Museum: Facilitating Public Engagement Through an Interactive Application.

Digitisation has become a common practice in the preservation of museum collections. Recent development of photogrammetry techniques allows for more accessible acquisition of three-dimensional (3D) models that serve as accurate representations of their originals. One of the potential applications of this is presenting digital collections as virtual museums to engage the public. Medical museums, particularly, would benefit from digitisation of their collections as many of them are closed to the public.The aim of this project was to design and create an interactive virtual museum which would represent the Anatomy Museum at the University of Glasgow with key specimens digitised using photogrammetry techniques. Members of the general public (25 participants) were asked to evaluate the usability and effectiveness of the interactive application by completing questionnaires.A process to digitise anatomical specimens using photogrammetry and convert them into game-ready 3D models was developed. The results demonstrated successful generation of 3D models of specimens preserved using different techniques, including specimens preserved in fluid and glass jars. User tests and evaluation of the application by members of the general public were positive, with participants agreeing that they would now consider visiting the real museum after using the virtual version.

Micro-plastination: technique for obtaining slices below 250 µm for the visualization of microanatomy in morphological and pathological morphology protocols / Micro-plastinación: técnica para la obtención de cortes inferiores a 250 µm para la visualización de la microanatomía en protocolos experimentales de morfología y patología

Plastination has revolutionized the study and research of anatomy, thanks to the biosecurity and indefinite preservation of human and animal bodies and organs. This paper presents the concept of Micro-Plastination, an ultra-thin sheet plastination technique, to obtain ultra-thin slices, of a thickness of less than 250 µm, for the identification and visualization of the microanatomy of any anatomical region in morphological and pathological experimental protocols.

La plastinación ha revolucionado el estudio y la investigación de la anatomía, gracias a la conservación biosegura y por tiempo indefinido de cadáveres y órganos humanos y animales. En este trabajo se presenta el concepto de Micro-Plastinación, técnica de plastinación de cortes ultrafinos para la obtención de cortes ultradelgados, de un grosor inferior a los 250 µm, para la identificación y visualización de la microanatomía de cualquier región anatómica en protocolos de morfología experimental.

Determination of whether morphometric analysis of vertebrae in the domestic cat (Felis catus) is related to sex or skull shape.

In many mammals, gender and skull shape are related to the bone morphology of the entire body; however, this has not been well established in the domestic cat (Felis catus). This study aims to find a relationship between cervical, thoracic and lumbar vertebrae morphometrics with regard to the sex and skull shape of domestic cats. A total of 79 samples obtained from 92 dried bones of domestic cats were used to determine morphometric measurements for a total of 29 parameters. Hierarchical clustering was used to cluster the vertebral bones found in three groups: C3-T1, T2-T11 and T12-L7. The skull shape identification process employed discriminative analysis and revealed the highest training data accuracy rate at up to 86.20% in T4 followed by L1 (86.04%) Axis (85.71%) and C5 (85.18%). Sex identification employed discriminative analysis and displayed the highest training data accuracy rate at up to 75.58% in L1 followed by, T7 (71.87%) and C6 (71.79%). Moreover, we found that 14% of the samples had one vertebra missing (T13 or L1). In conclusion, domestic cat vertebral morphometrics were found to be more related to skull shape than gender. In addition, bone clustering employed morphometric data and yielded a result that was similar to that of traditional cluster analysis involving body regions.

Three-dimensional geometric morphometric analysis of tooth shape in hypodontia: II size variation.

The study aimed to evaluate differences in tooth size between patients with hypodontia and those with normal complement of permanent teeth using three-dimensional geometric morphometric analysis. The number of anatomical landmarks was recorded on the clinical crown of the permanent teeth on three-dimensional scanned study models of hypodontia and in control subjects. The study sample comprised 120 patients with hypodontia (mild, moderate, severe) and 40 controls matched for age and sex. Tooth size differences were tested statistically using multivariate statistics. Size variation was for the most part found to be significant, especially when the control subjects were compared with the hypodontia groups. The explained variance among group membership was generally larger in the anterior and premolar region than in the molar region Sexual dimorphism was found less in the anterior region than in the posterior region; therefore, the sexes were pooled more often for teeth in the anterior region. Quantitative measurement of tooth size in patients with hypodontia may enhance the multidisciplinary management of these patients.

Sex-based differences in human sacroiliac joint shape: a three-dimensional morphological analysis of the iliac auricular surface of modern Japanese macerated bones.

The human pelvis is one of the skeletons where sex differences are expressed, but few detailed studies have been conducted on sex-related differences in the sacroiliac joint morphology. Therefore, we conducted a three-dimensional morphological analysis evaluation of the sacroiliac joints to clarify the sex-related difference of the joint's morphology. Right-side macerated innominate bones of Japanese males (n = 100) and females (n = 70) whose ages at death were recorded were included in the study. Three-dimensional images were created from the subjects' iliac auricular surface images, and 16 measurement parameters were acquired on the basis of 11 defined measurement points. All measurement parameters were compared between the male and female groups. The values of the measurement parameters indicating the size of the iliac auricular surface were significantly larger in the male group than in the female group. In addition, the angle between the short and long arms of the auricular surface was larger in the male group. Furthermore, on the basis of the corrected values of the physical disparity, the long arm dimension of the iliac auricular surface was larger in the male group, while the short arm dimension was larger in the female group. The sex-based differences in the iliac auricular surface morphology that were confirmed in this study may reflect the sex-based differences in the sacroiliac joint function. The findings of this study may contribute to the elucidation of the pathophysiology of the sacroiliac joint dysfunction that frequently occurs in women.