Comparación del Rectángulo de Euclides y la altura facial ideal / Comparison of euclid’s rectangle and ideal facial height

Objetivo: El propósito de este trabajo fueconocer la similitud estadística que existeentre la altura facial ideal propuesta en elmétodo cefalométrico Silva (MCS) y la altura facial obtenida utilizando el rectángulo áureo (o Rectángulo de Euclides).Método: Se utilizaron 100 imágenes cefalométricas de pacientes ortodónticosdel Departamento de Ortodoncia de laUniversidad Latinoamericana, campusValle de la Ciudad de México, de ambossexos, seleccionando aquellas que tuvieron características aptas para el trazadocefalométrico en cuestión, siendo ubicadas 85 de éstas en el programa Keynote(Apple®), realizando MCS y el trazado delRectángulo de Euclides, cuya correlaciónse estableció con el coeficiente de correlación de Pearson.Resultados: El análisis de Pearson obtuvo un resultado de correlación importante(r)=0.69058966Conclusiones: Los resultados estadísticos demuestran que la altura facial medida con el método cefalométrico Silva ycon el rectángulo de Euclides arrojan unacorrelación importante pero no perfecta(AU)

Objective: The purpose of this work wasto know the statistical similarity that existsbetween the ideal facial height proposedin the Silva cephalometric method (SCM)and the facial height obtained using thegolden rectangle (or Euclid’s Rectangle).Method: 100 cephalometric images oforthodontic patients of the Departmentof Orthodontics of the Latin AmericanUniversity, Valle campus in Mexico City,of both sexes were used, selecting thosethat had characteristics suitable for thecephalometric tracing in question, 85of these being located in the Keynoteprogram (Apple®), performing SCMand plotting the Euclid Rectangle, thecorrelation of which was established withPearson’s correlation coefficient.Results: Pearson’s analysis obtainedan important correlation result(r) = 0.69058966Conclusions: The statistical results showthat the facial height measured with thecephalometric method and the Euclideanrectangle shows an important but notperfect correlation(AU)

Mammalian face as an evolutionary novelty.

The anterior end of the mammalian face is characteristically composed of a semimotile nose, not the upper jaw as in other tetrapods. Thus, the therian nose is covered ventrolaterally by the "premaxilla," and the osteocranium possesses only a single nasal aperture because of the absence of medial bony elements. This stands in contrast to those in other tetrapods in whom the premaxilla covers the rostral terminus of the snout, providing a key to understanding the evolution of the mammalian face. Here, we show that the premaxilla in therian mammals (placentals and marsupials) is not entirely homologous to those in other amniotes; the therian premaxilla is a composite of the septomaxilla and the palatine remnant of the premaxilla of nontherian amniotes (including monotremes). By comparing topographical relationships of craniofacial primordia and nerve supplies in various tetrapod embryos, we found that the therian premaxilla is predominantly of the maxillary prominence origin and associated with mandibular arch. The rostral-most part of the upper jaw in nonmammalian tetrapods corresponds to the motile nose in therian mammals. During development, experimental inhibition of primordial growth demonstrated that the entire mammalian upper jaw mostly originates from the maxillary prominence, unlike other amniotes. Consistently, cell lineage tracing in transgenic mice revealed a mammalian-specific rostral growth of the maxillary prominence. We conclude that the mammalian-specific face, the muzzle, is an evolutionary novelty obtained by overriding ancestral developmental constraints to establish a novel topographical framework in craniofacial mesenchyme.

Age estimation of immature human skeletal remains from mandibular and cranial bone dimensions in the postnatal period.

Age estimation is one of the crucial first steps in the identification of human skeletal remains in both forensic and archeological contexts. In the postnatal period, age is traditionally estimated from dental development or skeletal growth, typically long bone diaphyseal length. However, in many occasions other methods are required. This study provides alternative means of estimating age of juvenile remains from the size of several cranial bones and the mandible. A sample of 185 identified juvenile skeletons between birth and 13 years of age from two European collections were used (Lisbon and Spitalfields). Measurements of the frontal, occipital-lateralis, occipital-basilaris, occipital-squamous, zygomatic, maxilla, and mandible were used to calculate classical calibration regression formulae for the sexes combined. The sample was divided into three age groups birth-2 years, 2-6 years, and 2-12.9 years, depending on bone and its growth trajectory. For all the bones, measurements of the youngest age groups yielded the most precise age estimates. The vault bones on average yielded the best performing models, with the frontal bone having the most precise of all. The mandible performed on par with the best performing cranial bones, particularly in individuals under the age of 2 years. This study provides one of the most comprehensive approaches to juvenile age estimation based on bones of the skull, providing a resource that potentially can help estimate age of juvenile skeletons from a variety of circumstances.

Correlation between craniofacial structures, anthropometric measurements, and nasopharyngeal dimensions in black adolescents.

OBJECTIVES: To evaluate the correlation between craniofacial structures, anthropometric measurements, and bony and soft tissue nasopharyngeal dimensions in African Black adolescents. METHODS: This retrospective cross-sectional study was conducted on 483 healthy adolescents (250 females and 233 males), randomly selected from one dental clinic. The inclusion criteria were skeletal and dental Class I, Black ethnicity, pubertal growth period as determined by the Greulich and Pyle atlas criteria, and no history of orthodontic treatment. Anthropometric measurements (stature, upper body height, lower body height, and BMI) and radiographic records (hand-wrist radiographs, and lateral cephalograms) were obtained. One investigator traced and analysed all cephalograms to determine three skeletal craniofacial parameters (maxillary length [Ar- ANS], mandibular length [Ar-Gn], and lower anterior facial height [ANS-Me]), and 14 (8 skeletal and 6 soft tissue) nasopharyngeal parameters. Pearson correlation coefficients and stepwise multiple linear regression analyses were conducted. RESULTS: The mean skeletal ages of females and males were 11.31±2.31y and 12.66±1.85y, respectively. Multiple linear regression analyses showed that stature, posterior height of nasal cavity (S-PNS), length of nasal floor (AA-PNS), and mean area of bony nasopharynx (Area 1) were significantly correlated with maxillary length, P<.001. Stature, BMI, S-PNS, vertical angle of nasopharynx (Ba-S-PNS), Area 1, adenoid height (AD), and linear hyoid bone measurements (H-AA, H-RGN, H-Ax) were all correlated with mandibular length, P<.05. Lower facial height showed sexual dimorphism and was significantly associated with vertical nasopharyngeal measurements, BMI and upper body height. CONCLUSIONS: Craniofacial structures were significantly associated with stature and upper body height. Maxillary growth was associated with bony nasopharyngeal variables. Mandibular growth and lower facial height were associated with bony and soft tissue nasopharyngeal variables. The sexual dimorphism in lower facial height warrants future studies to fully understand and manage the craniofacial complex and nasopharyngeal airway in African Black adolescents.

Architectural changes in alveolar bone for dental decompensation before surgery in Class III patients with differing facial divergence: a CBCT study.

This study aimed to investigate alveolar bone change around mandibular anterior teeth during orthodontic decompensation in patients with skeletal Class III malocclusion and different vertical facial patterns. The records of 29 consecutive Class III patients selected from those pending two-jaw orthognathic surgery were divided into low (≤ 28°), average (30°-37°), and high (≥ 39°) mandibular plane angle (MPA) groups. The DICOM files of CBCT scans and STL files of digital dental models, taken before (T1) and after (T2) presurgical orthodontic treatment, were imported into Dolphin imaging software to reconstruct dentoskeletal images. T1 and T2 images were superimposed and analyzed for bone thickness and height at the level of root apex on each mid-sagittal slice of six mandibular anterior teeth. Differences between T1 and T2 were analyzed by non-parametric tests and mixed-effect model analysis. The results showed that the measurements of alveolar bone height generally decreased after treatment, regardless of MPA. The facial divergence, incisor irregularity, tooth site, treatment time, and change in proclination were identified as the significant factors affecting alveolar bone thickness and height during treatment. The presurgical orthodontic treatment to decompensate mandibular anterior teeth should be very careful in all MPA groups.

CT-Based Measurements of Facial Parameters of Healthy Children and Adolescents in Thailand.

BACKGROUND AND PURPOSE: Facial parameters are used for evaluating normal growth patterns, diagnosing patients with craniofacial abnormalities, and planning surgical procedures. However, these parameters vary by ethnicity and race. This study aims to describe soft-tissue and bony facial parameters based on CT of healthy pediatric and adolescent patients in Thailand. MATERIALS AND METHODS: CT imaging of the brain, orbit, facial bones, and neck was performed at Maharaj Nakorn Chiangmai Hospital, in patients from birth to 19 years old. Patients with known syndromic disease, craniofacial syndrome, facial trauma and/or infection, and previous surgery that deformed the study area were excluded. The key points of measurement were soft-tissue intercanthal, bony interorbital, and bony lateral orbital distances. RESULTS: There were 932 patients: 554 males (59.4%) and 378 females (40.6%). Facial parameters rapidly increased in the first 2 years of life. Significant differences in these parameters between the males and females were found at the age of ≥15 years. However, ratios of the interorbital to the lateral orbital distance were generally consistent among age groups in both sexes, at 0.25. CONCLUSIONS: This study, in Thailand, provides detailed age- and sex-specific normative data of the craniofacial measurements in children and adolescences based on CT imaging. These data can be used for evaluating individual patients with craniofacial abnormalities as well as determining the treatment in Thai and Asian populations, in whom craniofacial abnormalities, for example, frontoethmoidal encephalomeningocele, are common.

Soft tissue thickness in Brazilian adults of different skeletal classes and facial types: A cone beam CT - Study.

The aim in this study was to evaluate the influence of skeletal class, facial type, and sex on soft tissue thickness (STT) of the craniofacial midline in a Brazilian subpopulation. Thus, 121 cone beam computed tomography (CBCT) scans (54 males and 67 females, age 21 to 40 yrs) composed the study sample. Patients were classified according to skeletal class (class I, II, and III) and facial type (brachycephalic, mesocephalic, and dolichocephalic), and STT was measured (mm) in 10 landmarks in the craniofacial midline for each CBCT scan. Multivariate analysis of covariance evaluated facial STT with regard to multiple independent variables (sex, age - covariate, facial type, and skeletal class). TEM and rTEM assessed the intra-examiner agreement. STT was significantly greater in males than in females for all regions measured (p < 0.05), except for the pogonion-pogonion' landmark (p>0.05). In general, class III individuals had significantly thicker soft tissue in the maxilla - subspinale-subnasale', prosthion-labrale superius', and incision-stomion' regions, while class II subjects had thicker soft tissue in the infradentale-labrale inferius' mandibular landmark (p < 0.05). Regarding facial type, dolichocephalic individuals showed significantly thicker soft tissue in the supramentale-supramentale' mandibular landmark, whereas brachycephalic subjects had thicker soft tissue in maxillary regions - prosthion-labrale superius' and incision-stomion' (p < 0.05). rTEM values were below 5% for most landmarks, and all TEM values were below 1 mm. Skeletal class and facial type influence STT, showing a soft tissue compensation, with deeper soft tissue in areas with lower skeletal development, and/or where bone is positioned more posteriorly.

Facial shape and allometry quantitative trait locus intervals in the Diversity Outbred mouse are enriched for known skeletal and facial development genes.

The biology of how faces are built and come to differ from one another is complex. Discovering normal variants that contribute to differences in facial morphology is one key to untangling this complexity, with important implications for medicine and evolutionary biology. This study maps quantitative trait loci (QTL) for skeletal facial shape using Diversity Outbred (DO) mice. The DO is a randomly outcrossed population with high heterozygosity that captures the allelic diversity of eight inbred mouse lines from three subspecies. The study uses a sample of 1147 DO animals (the largest sample yet employed for a shape QTL study in mouse), each characterized by 22 three-dimensional landmarks, 56,885 autosomal and X-chromosome markers, and sex and age classifiers. We identified 37 facial shape QTL across 20 shape principal components (PCs) using a mixed effects regression that accounts for kinship among observations. The QTL include some previously identified intervals as well as new regions that expand the list of potential targets for future experimental study. Three QTL characterized shape associations with size (allometry). Median support interval size was 3.5 Mb. Narrowing additional analysis to QTL for the five largest magnitude shape PCs, we found significant overrepresentation of genes with known roles in growth, skeletal and facial development, and sensory organ development. For most intervals, one or more of these genes lies within 0.25 Mb of the QTL's peak. QTL effect sizes were small, with none explaining more than 0.5% of facial shape variation. Thus, our results are consistent with a model of facial diversity that is influenced by key genes in skeletal and facial development and, simultaneously, is highly polygenic.

A tiny new Middle Triassic stem-lepidosauromorph from Germany: implications for the early evolution of lepidosauromorphs and the Vellberg fauna.

The Middle Triassic was a time of major changes in tetrapod faunas worldwide, but the fossil record for this interval is largely obscure for terrestrial faunas. This poses a severe limitation to our understanding on the earliest stages of diversification of lineages representing some of the most diverse faunas in the world today, such as lepidosauromorphs (e.g., lizards and tuataras). Here, we report a tiny new lepidosauromorph from the Middle Triassic from Vellberg (Germany), which combines a mosaic of features from both early evolving squamates and rhynchocephalians, such as the simultaneous occurrence of a splenial bone and partial development of acrodonty. Phylogenetic analyses applying different optimality criteria, and combined morphological and molecular data, consistently recover the new taxon as a stem-lepidosauromorph, implying stem-lepidosauromorph species coinhabited areas comprising today's central Europe at the same time as the earliest known rhynchocephalians and squamates. It further demonstrates a more complex evolutionary scenario for dental evolution in early lepidosauromorphs, with independent acquisitions of acrodonty early in their evolutionary history. The small size of most terrestrial vertebrates from Vellberg is conspicuous, contrasting to younger Triassic deposits worldwide, but comparable to Early Triassic faunas, suggesting a potential long-lasting Lilliput effect in this fauna.

Concepts of Facial Aesthetics When Considering Ethnic Rhinoplasty.

Facial plastic surgeons must understand nasal aesthetics in the context of race, ethnicity, and culture. The lack of aesthetic norms and ideal standards in non-Caucasian patients and the variation in nasal anatomy and morphology among races can create a challenge in approaching ethnic rhinoplasty. Preoperative assessment of nasal and facial features that contribute to a nose that is unpleasing for a non-Caucasian patient cannot be based on neoclassical canons. This article describes the concepts of facial aesthetics important to approaching ethnic rhinoplasty. Understanding these features will allow the surgeon to achieve nasal symmetry and improved definition without effacing ethnicity.

Tubérculo marginal del hueso cigomático / Marginal tubercle of zygomatic bone

El hueso cigomático, ubicado en la parte superior y lateral de la cara, es un hueso par e irregular con forma cuadrilátera o romboidal. Se describen 2 caras, 4 aristas y 4 ángulos, forma cavidades, permite la inserción muscular y aponeurótica, es parte de la arquitectura facial, distribuye las fuerzas masticatorias y permite el paso del nervio cigomático. Su margen postero-superior presenta una prominencia ósea conocida como tubérculo marginal, en el que se observa la inserción de la fascia temporal. El objetivo de este trabajo fue describir las características particulares de esta prominencia. La muestra correspondió a 30 cráneos de adultos chilenos de ambos sexos. A través de una serie de puntos óseos, se describió la presencia, ubicación, tamaño, forma, cortical y trabeculado del tejido óseo del tubérculo marginal. Para realizar las mediciones se utilizaron cámara digital, compas de precisión y cáliper digital. El análisis radiográfico requirió tomografía computarizada de alta resolución. Los resultados mostraron que el tubérculo marginal del hueso cigomático es una prominencia constante, ubicada en el tercio medio del proceso frontal del hueso y que la mayoría de los individuos mostraron una forma semilunar. Su altura fluctúa entre 3 y 4 mm, siendo más pronunciada en hombres que en mujeres. El grosor de la corteza ósea es directamente proporcional a la prominencia del tubérculo, mientras que el trabeculado esponjoso está inversamente relacionado con este último. El análisis de estos resultados parece indicar que las fuerzas biomecánicas ejercidas por la musculatura masticatoria y transmitidas por la fascia temporal, determinan la morfología externa e interna de esta prominencia y del propio hueso cigomático. Concluimos, declarando la necesidad de revisar el conocimiento anatómico a la luz de las nuevas técnicas de imagen e integración disciplinar.

The zygomatic bone, located in the upper and lateral area of the face, is an even and irregular quadrilateral or rhomboid shaped bone. It presents 2 faces, 4 margins and 4 angles. It forms cavities, allows muscular and aponeurotic insertion, is part of the facial architecture, distributes masticatory forces and allows the passage of the zygomatic nerve. Its postero-superior margin presents a bony prominence known as a marginal tubercle, in which the insertion of the temporal fascia is observed. The objective of this work was to describe the particular characteristics of this prominence. The sample corresponded to 30 skulls of Chilean adults of both sexes. Through a series of bone points, the presence, location, size, shape, cortical and trabeculate of the bone tissue of the marginal tubercle was described. A digital camera, precision compass and digital caliper were used to perform the measurements. The radiographic analysis required high-resolution computed tomography. The results showed that the marginal tubercle of the zygomatic bone is a constant prominence, located in the middle third of the frontal process of the bone and that most individuals showed a semilunar shape. Its height fluctuated between 3 and 4 mm, being more pronounced in men than in women. The thickness of the bone cortex was directly proportional to the prominence of the tuber, while the spongy trabeculate was inversely related to the latter. The analysis of these results seems to indicate that the biomechanical forces exerted by the masticatory musculature and transmitted by the temporal fascia, determine the external and internal morphology of this prominence, and of the zygomatic bone itself. In conclusion, it is recommended to review anatomical knowledge in the light of new imaging techniques and disciplinary integration.

Morphological consequences of artificial cranial deformation: Modularity and integration.

The cranium is an anatomically complex structure. One source of its complexity is due to its modular organization. Cranial modules are distinct and partially independent units that interact substantially during ontogeny thus generating morphological integration. Artificial Cranial Deformation (ACD) occurs when the human skull is intentionally deformed, through the use of different deforming devices applied to the head while it is developing. Hence, ACD provides an interesting example to assess the degree to which biomechanical perturbations of the developing neurocranium impact on the degree of morphological integration in the skull as a whole. The main objective of this study was to assess how ACD affects the morphological integration of the skull. This was accomplished by comparing a sample of non-deformed crania and two sets of deformed crania (i.e. antero-posterior and oblique). Both developmental and static modularity and integration were assessed through Generalized Procrustes Analysis by considering the symmetric and asymmetric components of variation in adults, using 3D landmark coordinates as raw data. The presence of two developmental modules (i.e. viscero and neurocranium) in the skull was tested. Then, in order to understand how ACD affects morphological integration, the covariation pattern between the neuro and viscerocranium was examined in antero-posterior, oblique and non-deformed cranial categories using Partial Least-Squares. The main objective of this study was to assess how ACD affects the morphological integration of the skull. This was accomplished by comparing a sample of deformed (i.e. antero-posterior and oblique) and non-deformed crania. Hence, differences in integration patterns were compared between groups. The obtained results support the modular organization of the human skull in the two analyzed modules. The integration analyses show that the oblique ACD style differentially affects the static morphological integration of the skull by increasing the covariance between neuro and viscerocranium in a more constrained way than in antero-posterior and non-deformed skulls. In addition, the antero-posterior ACD style seems to affect the developmental integration of the skull by directing the covariation pattern in a more defined manner as compared to the other cranial categories.

Location of the infraorbital foramen with reference to soft tissue landmarks for regional nerve blocks during midface surgery.

PURPOSE: An infraorbital nerve (ION) block is widely used to accomplish regional anesthesia during surgical procedures involving the midface region. This study aimed to elucidate the exact location of the infraorbital foramen (IOF) in relation to clinically useful soft-tissue landmarks for achieving an effective ION block. METHODS: Forty-three hemifaces from 23 embalmed Korean cadavers were dissected. The lateral canthus, peak of Cupid's bow, medial limbus, and midline were used as reference points. The distances from the IOF to the midline and the lateral canthus were measured. RESULTS: The IOF was located approximately 25 mm below the lateral canthus and 27 mm lateral to the midline. In all cases, the IOF was situated within 9.0 mm of the crossing point of the oblique line connecting the lateral canthus to the peak of Cupid's bow and the vertical line through the medial limbus. CONCLUSION: Considering the spread of an anesthetic agent, injecting it into the crossing point of the oblique line through the lateral canthus to the peak of Cupid's bow and the vertical line through the medial limbus would successfully block the ION in most patients.

Three-dimensional evaluation of important surgical landmarks of the face during aging.

BACKGROUND: One surgical objective is creating an aesthetically satisfying outcome. The morbidity increases with age. Standard values for areas of the face, which are frequently surgically treated, are needed for the surgeon. METHODS: 240 Caucasians aged 21-65 were divided into six subgroups by gender and age. They were scanned by a three-dimensional (3D) scanner. Distances and angles in faces between landmarks were evaluated. RESULTS: During aging, the relation of the eye's width to the eye's height became significantly smaller (M: p=0.001, F: p≤0.0001). The outer contour of the nose became significantly sharper with increasing age (M: p=0.001, F: p=0.0021). Seen from caudal, the nose formed an isosceles triangle with the base between the left and right alar curvature and the base had an average length of 31.35mm±2.97mm. The leg of this triangle had an average length of 33.67mm±2.09mm. The nose got longer and wider during aging; the age-dependent changes between the different groups of males (p≤0.0001) and the difference between females and males were significant (p≤0.0001). The thickness of the nasal wings remained the same size during a lifetime. Females had significantly greater heights for both lips (p≤0.0001, p=0.027). In males and females, the heights decreased with increasing age. CONCLUSION: This study provided a database of measurements of parts of the face, especially those parts that can underlie various surgical treatments.

An interactive and intuitive visualisation method for X-ray computed tomography data of biological samples in 3D Portable Document Format.

3D imaging approaches based on X-ray microcomputed tomography (microCT) have become increasingly accessible with advancements in methods, instruments and expertise. The synergy of material and life sciences has impacted biomedical research by proposing new tools for investigation. However, data sharing remains challenging as microCT files are usually in the range of gigabytes and require specific and expensive software for rendering and interpretation. Here, we provide an advanced method for visualisation and interpretation of microCT data with small file formats, readable on all operating systems, using freely available Portable Document Format (PDF) software. Our method is based on the conversion of volumetric data into interactive 3D PDF, allowing rotation, movement, magnification and setting modifications of objects, thus providing an intuitive approach to analyse structures in a 3D context. We describe the complete pipeline from data acquisition, data processing and compression, to 3D PDF formatting on an example of craniofacial anatomical morphology in the mouse embryo. Our procedure is widely applicable in biological research and can be used as a framework to analyse volumetric data from any research field relying on 3D rendering and CT-biomedical imaging.

Complex Nature of Hominin Dispersals: Ecogeographical and Climatic Evidence for Pre-Contact Craniofacial Variation.

Coordinate data analysis of ancient crania from the New World reveals complexity in interpretation when addressing ancient population dispersals. The results of this study generally support a geographic patterning for the New World; however, it also revealed a much more complex and multifactorial mechanism shaping craniofacial morphology that should be considered when investigating ecogeographic models for hominin dispersals. We show that craniofacial variation is not the result of a single mechanism but is a much more complex interaction of environmental and microevolutionary forces.

Dental development and craniofacial morphology in school-age children.

INTRODUCTION: The growth of the craniofacial complex is important for establishing a balanced relationship among the teeth, jaws, and other facial structures. However, there is still a lack of information about craniofacial parameters that are affected by the rate of dental development. The aim of this study was to investigate the association between dental development and craniofacial morphology in school-age children. METHODS: This study was embedded in the Generation R Study, Rotterdam, The Netherlands. In 3,896 children aged 8 to 11 years, dental development was assessed from panoramic radiographs and craniofacial morphology was assessed by combining cephalometric parameters into 9 uncorrelated principal components, each representing a distinct skeletal or dental craniofacial pattern. The statistical analysis was performed using linear and nonlinear regression model. RESULTS: Dental development was positively associated with the bimaxillary growth (ß = 0.04; 95% CI 0.01 to 0.08). Children with above-average dental development had a tendency toward Class II jaw relationship (ß = -0.08; 95% CI -0.13 to -0.04). Regarding dental parameters, the proclination increased for incisors and lips with advanced dental development (ß = 0.15 [95% CI 0.10 to 0.19] and ß = 0.13 [95% CI 0.09 to 0.17], respectively), but the incisor proclination remained more pronounced in children that had above-average dental development. CONCLUSIONS: The findings of this large population-based study show that dental development is associated with specific dental and skeletal cephalometric characteristics in school-age children. Further longitudinal studies are necessary to confirm the observed effects over time.

Sutural Morphology in the Craniofacial Skeleton: A Descriptive Microcomputed Tomography Study in a Swine Model.

Sutures are greatly involved in both normal craniofacial growth and developmental anomalies. Having clear parameters for defining their morphology is fundamental to properly investigate their physiological or pathological development. However, the current literature is lacking of well-defined methods for the assessment of these structures. This study performed a comprehensive microcomputed tomography (µCT) analysis of a swine model evaluating morphological variation of sutures in different skull regions. Seventy-two suture samples were removed from one swine (Sus scrofa), approximately 9-12-month-old. Each sample was analyzed with µCT in the parallel (PAR) and perpendicular (PER) plane with respect to the bone surface. Suture width (S w ), linear obliteration index (LOI), and linear interdigitation index (LII) were calculated in each of the two reference planes, and sutures were categorized in four types (S t ). Parameters were compared among the facial, craniofacial, and cranial region. Description of the main morphological parameters was provided, and differences were found between the parallel and perpendicular planes. S t varied depending on the skull region, with simple sutures more represented in the cranial region. LII in the perpendicular plane decreased from facial to craniofacial and cranial region. S w in the parallel plane decreased from facial and craniofacial to cranial region. In the swine model, the sutural width, linear interdigitation, and suture type were related to distinct skull regions. The suture type was introduced to allow a better morphological characterization of sutures as 3D structures. Clear definition of sutural parameters is important for appropriate description of these complex structures. Anat Rec, 302:2156-2163, 2019. © 2019 American Association for Anatomy.

Morphological integration affects the evolution of midline cranial base, lateral basicranium, and face across primates.

OBJECTIVES: The basicranium and face are two integrated bony structures displaying great morphological diversity across primates. Previous studies in hominids determined that the basicranium is composed of two independent modules: the midline basicranium, mostly influenced by brain size, and the lateral basicranium, predominantly associated with facial shape. To better assess how morphological integration impacts the evolution of primate cranial shape diversity, we test to determine whether the relationships found in hominids are retained across the order. MATERIALS AND METHODS: Three-dimensional landmarks (29) were placed on 143 computed tomography scans of six major clades of extant primate crania. We assessed the covariation between midline basicranium, lateral basicranium, face, and endocranial volume using phylogenetically informed partial least squares analyses and phylogenetic generalized least squares models. RESULTS: We found significant integration between lateral basicranium and face and between midline basicranium and face. We also described a significant correlation between midline basicranium and endocranial volume but not between lateral basicranium and endocranial volume. DISCUSSION: Our findings demonstrate a significant and pervasive integration in the craniofacial structures across primates, differing from previous results in hominids. The uniqueness of module organization in hominids may explain this distinction. We found that endocranial volume is significantly integrated to the midline basicranium but not to the lateral basicranium. This finding underlines the significant effect of brain size on the shape of the midline structures of the cranial base in primates. With the covariations linking the studied features defined here, we suggest that future studies should focus on determining the causal links between them.

The panoramic dental radiograph for emergency physicians.

Dental emergencies are common reasons for presenting to hospital emergency departments. Here, we discuss the panoramic radiograph (orthopantomogram (OPG, OPT) as a diagnostic tool for the assessment of mandibular trauma and odontogenic infections. In this article, we review the radiographic principles of image acquisition, and how to conduct a systematic interpretation of represented maxillofacial anatomy. The aim is to equip the emergency physician with the skills to use the OPG radiograph when available, and to rapidly assess the image to expedite patient management. Included is a discussion of a number of cases seen in the emergency setting and some common errors in diagnosis.