Insertion Area Research Articles

An anatomical study of the fetal superior capsule of the glenohumeral joint

IntroductionThe superior part of the glenohumeral joint capsule has an intimate relationship with the tendons of the rotator cuff and the tendon of the long head of the biceps. One of the strategies currently proposed in the event of a massive cuff rupture is to reconstruct this superior capsule. The main objective of this anatomical study was to describe the superior joint capsule of the embryonic glenohumeral joint and its relationship to the tendons of the rotator cuff. HypothesisThe hypothesis was that this structure was an anatomical entity, morphologically identifiable from the embryogenesis of the joint (more pronounced tissue boundaries in the fetus). Material and methodsIn total, 101 continuous fetal anatomical sections (4 fetuses of 336mm), in the frontal plane, made it possible to identify and measure: diameters of the humeral head and glenoid, dimensions of the joint capsule insertion zone at the level of the greater tubercle, as well as the different thicknesses of this insertion zone. The ratios above the head of the biceps and against the superior labrum were also measured. ResultsAt the level of its distal insertion on the greater tuberosity, the thickness of the superior joint capsule varies on average between 0.8mm laterally and 1.2mm next to the tendons of the supraspinatus and infraspinatus; the thickness is 0.9mm next to the middle part of the supraspinatus tendon (the “rotator cable” zone). For its insertion at the level of the glenoid labrum, the superior capsule measures 0.6mm thick on average. The capsule around the tendon of the long head of the biceps is 1.5mm thick on average. DiscussionHere, we confirm the existence of this superior joint capsule, which can potentially be reconstructed. It is inserted on the greater tubercle covering 30 to 60% of its surface with variations in thickness. The joint capsule is fused to the supraspinatus tendon at the rotator cuff insertion area, preventing independent reinsertion of the tendon. Level of evidenceIV; anatomical study.

Bone Staples Provide Favorable Primary Stability in Cortical Fixation of Tendon Grafts for Medial Collateral Ligament Reconstruction: A Biomechanical Study.

Background:The use of the interference screw (IFS) for the cortical fixation of tendon grafts in knee ligament reconstruction may lead to converging tunnels in the multiligament reconstruction setting. It is unknown whether alternative techniques using modern suture anchor (SA) or bone staple (BS) fixation provide sufficient primary stability.Purpose:To assess the primary stability of cortical fixation of tendon grafts for medial collateral ligament (MCL) reconstruction using modern SA and BS methods in comparison with IFS fixation.Study Design:Controlled laboratory study.Methods:Cortical tendon graft fixation was performed in a porcine knee model at the tibial insertion area of the MCL using 3 different techniques: IFS (n = 10), SA (n = 10), and BS (n = 10). Specimens were mounted in a materials testing machine, and cyclic loading for 1000 cycles at up to 100 N was applied to the tendon graft, followed by load-to-failure testing. Statistical analysis was performed using 1-way analysis of variance.Results:There were no statistical differences in elongation during cyclic loading or peak failure load during load-to-failure testing between BS (mean ± standard deviation: 3.4 ± 1.0 mm and 376 ± 120 N, respectively) and IFS fixation (3.9 ± 1.2 mm and 313 ± 99.5 N, respectively). SA fixation was found to have significantly more elongation during cyclic loading (6.4 ± 0.9 mm; P < .0001) compared with BS and IFS fixation and lower peak failure load during ultimate failure testing (228 ± 49.0 N; P < .01) compared with BS fixation.Conclusion:BS and IFS fixation provided comparable primary stability in the cortical fixation of tendon grafts in MCL reconstruction, whereas a single SA fixation led to increased elongation with physiologic loads. However, load to failure of all 3 fixation techniques exceeded the loads expected to occur in the native MCL.Clinical Relevance:The use of BS as a reliable alternative to IFS fixation for peripheral ligament reconstruction in knee surgery can help to avoid the conflict of converging tunnels.

The impact of guidelines on sterility precautions during indwelling urethral catheterization at two acute-care hospitals in Sweden - a descriptive survey

BackgroundTo support a uniform and evidence-based practice for indwelling urinary catheterization in adults The European association of Urology Nurses (EAUN) published guidelines for this procedure in 2012. The Swedish national guidelines are based on the sterility precautions advocated by EAUN. Some hospitals have local guidelines with other requirements concerning sterility and leave to staff to decide how to perform the catheterization. The aim of this descriptive survey was to investigate the nurses´ self-reported sterility precautions during indwelling urethral catheterization at two acute-care hospitals, where the local guidelines differ in their sterility requirements. The study also aimed to analyze factors affecting conformity with sterility precautions in the EAUN-guidelines.MethodsA structured questionnaire with questions concerning the participant, working conditions and performance of indwelling urethral catheterization was left to 931 nurses in two acute care hospitals. Chi-square test, Fisher’s exact test and Mann-Whitney U-test were used for descriptive statistics. Logistic regression was used to analyze variables associated with practicing the sterility precautions in the EAUN-guidelines.ResultsAnswers were obtained from 852 persons (91.5%). Most of the participants called their insertion technique “non-sterile”. Regardless of designation of the technique the participants said that the indwelling urinary catheter (IUC) should be kept sterile during procedure. Despite that not everyone used sterile equipment to maintain sterility of the catheter. The nurses´ conformity with all the sterility precautions in the EAUN-guidelines were associated with working at departments for surgery and cardiology (OR 2.35, 95% CI 1.69–3.27), use of sterile set for catheterization (OR 2.06, 95% CI 1.42–2.97), use of sterile drapes for dressing on insertion area (OR 1.91, 95% CI 1.24–2.96) and using the term “sterile technique” for indwelling urethral catheterization (OR 1.64, 95% CI 1.11–2.43).ConclusionsOnly 55–74% of the nurses practiced one or more precautions that secured sterility of the IUC thus demonstrating a gap between the EAUN-guidelines and the actual performance. Adherence to the guidelines was associated with factors that facilitated an aseptic performance such as using a sterile set and sterile drapes.Healthcare-settings should ensure education and skill training including measures to ensure that the IUC is kept sterile during insertion.

THE CLINICAL-BIOLOGICAL EFFECTS OF PERIODONTAL CURETTAGE IN DENTAL PRACTICE

Periodontal curettage is one of the basic procedures in marginal periodontium surgery. It is performed during the initial treatment phase of periodontal diseases, which occurs after emergency treatment (when appropriate) of acute complications of chronic marginal periodontal diseases. Periodontal curettage may be divided according to the area where it is performed in: gingival periodontal curettage, subgingival periodontal curettage. Gingival periodontal curettage is performed in the gingival groove and in the false gingival pockets, without usually exceeding the junctional epithelium insertion area. The main objective of subgingival periodontal curettage is to restore gingival health by removing from the root surface the factors that can cause gingival inflammation. The personal study was performed on two groups which included 82 patients. When analyzing the results, we relied on the justified assumption of the study that each case in the large framework of periodontal diseases represents a particular clinical-radiological and etiological reality as concerns its frequency and evolution (especially in terms of complications). The social origin and the cultural background play a very important role in the development of this relationship, which is at its best when both the doctor and the patient are closer from these points of view.

An experimental dynamic analysis of Z-pinned unidirectional CFRP beams

The application of composites in mechanical components has been growing gradually over the years. In general, laminated composite material have excellent mechanical resistance to in-plane loads, however, for out-of-plane loads this resistance decreases considerably due the weakness of matrix, that is responsible to keep layers mechanically connected. This may lead the structure to present a high vulnerability to delamination between the layers. The delamination is a common problem in composite materials and frequently occurs due the appearance of interlaminar shear stresses or loads under impact spreading damage along the matrix area of composite. To increase the resistance to delamination in composite laminates, different techniques for inserting reinforcements through thickness are applied including stitching, z-anchoring, tufting and z-pinning. This work aims to evaluate the influence of z-pinning on the modal responses. The z-pinning process was made considering machined rectangular carbon fiber/epoxy z-pins with different dimensions at different insertion spacing densities on the structure. Both the insertion density and the dimensions of the pin were obtained by RSM analysis to evaluate the influence on the mechanical modal properties (natural frequency, loss factor and vibration amplitude) and to obtain an ideal value of insertion area density and pin width. Experimental results have shown that the pin has a statistically significant influence on modal responses, allowing a reduction of up to 110% in vibration levels.

The Diagnostic Significance of Ultrasonographic Measurement of the Achilles Tendon Thickness for the Insertional Achilles Tendinopathy in Patients with Heel Pain.

No consensus exists concerning the diagnostic role or cutoff value of the Achilles tendon thickness on ultrasonography (US) for the diagnosis of insertional Achilles tendinopathy. This study sought to assess the diagnostic utility of US measurement of the thickness and echogenicity of the Achilles tendon for the insertional Achilles tendinopathy in patients with heel pain, and to compare the results with those of the plantar fascia for the plantar fasciitis. We conducted US examinations in consecutive patients who presented with unilateral or bilateral heel pain at the foot clinic of a single tertiary hospital from February 2016 to December 2020. Each US evaluation assessed the thickness and echogenicity of the insertion area of the Achilles tendon and plantar fascia. We retrospectively compared these parameters between patients with insertional Achilles tendinopathy or plantar fasciitis and normal controls and analyzed the diagnostic utility of these parameters. Based on clinical diagnosis, 44 feet were diagnosed with insertional Achilles tendinopathy, 109 feet were diagnosed with plantar fasciitis, and 32 feet were classified as normal. There was a significant difference in the thickness of the plantar fascia between the plantar fasciitis and normal control groups (p = 0.032). There was also a significant difference in the echogenicity of the plantar fascia between the plantar fasciitis and normal groups (p < 0.001). However, there was no significant difference in the thickness of the insertional area of the Achilles tendon between the insertional Achilles tendinopathy and normal groups (p = 0.132). There was a significant difference in the echogenicity of the insertional area of the Achilles tendon between the insertional Achilles tendinopathy and normal groups (p < 0.001). US measurement of the thickness of the insertional area of the Achilles tendon might not reflect the clinical status of insertional Achilles tendinopathy, unlike that of plantar fasciitis.

Generating biomembrane-like local curvature in polymersomes via dynamic polymer insertion

Biomembrane curvature formation has long been observed to be essential in the change of membrane morphology and intracellular processes. The significant importance of curvature formation has attracted scientists from different backgrounds to study it. Although magnificent progress has been achieved using liposome models, the instability of these models restrict further exploration. Here, we report a new approach to mimic biomembrane curvature formation using polymersomes as a model, and poly(N-isopropylacrylamide) to induce the local curvature based on its co-nonsolvency phenomenon. Curvatures form when poly(N-isopropylacrylamide) becomes hydrophobic and inserts into the membrane through solvent addition. The insertion area can be fine-tuned by adjusting the poly(N-isopropylacrylamide) concentration, accompanied by the formation of new polymersome-based non-axisymmetric shapes. Moreover, a systematic view of curvature formation is provided through investigation of the segregation, local distribution and dissociation of inserted poly(N-isopropylacrylamide). This strategy successfully mimicks biomembrane curvature formation in polymersomes and a detailed observation of the insertion can be beneficial for a further understanding of the curvature formation process. Furthermore, polymer insertion induced shape changing could open up new routes for the design of non-axisymmetric nanocarriers and nanomachines to enrich the boundless possibilities of nanotechnology.

EFEKTIFITAS PERAWATAN INFUS UMBILIKAL TERHADAP TIMBULNYA FLEBITIS PADA NEONATUS

&lt;strong&gt;Background &lt;/strong&gt;: The things to do to prevent from the appearance of phlebitis are the changing of the wound covering sterilized dressing, the evaluation to the appearance of phlebitis, the changing of the insertion area at every 48-72 hours, and the use of new catheterization set. The neonatus catheterization is usually placed at umbilical vein. As a result the neonatus with umbilical catheterization is easy to get phlebitis if the catheterization isn’t appropriate. &lt;strong&gt;Objective &lt;/strong&gt;: To understand the difference of the effectiveness of the umbilical intravenous catheterization nursing using dry sterilized dressing and covered antiseptic sterilized dressing concerned with the appearance of phlebitis on neonatus. &lt;strong&gt;Method : &lt;/strong&gt;The study was a queasy-experiment with post-test only design; used to examine the difference of effectiveness of the umbilical intravenous catheterization nursing using dry sterilized dressing and covered antiseptic sterilized dressing concerned with the appearance of phlebitis on neonatus. &lt;strong&gt;Result &lt;/strong&gt;: The result showed that there was no significant differences in the use of the dry sterilized dressing nursing and the covered antiseptic sterilized one as shown by p value score as much as 0,663 &amp;gt;0,05 with the fact that the Low Birth-weight babies and premature ones tend to have phlebitis. &lt;strong&gt;Conclusion : &lt;/strong&gt;There is no significant differences&lt;strong&gt; &lt;/strong&gt;in the umbilical catheterization nursing between use of the dry sterilized dressing and the covered antiseptic sterilized one concerned with the appearance of phlebitis but there is a tendency that the low birth-weight neonatus and premature ones will have phlebitis more easily.

Associated injury complicated by pediatric lower limb shaft fractures and clinical efficacy of flexible stainless-steel intramedullary nailing in children less than 15 years old.

Although pediatric lower limb shaft fractures are common, little is known about associated injuries. The purpose of this study was to examine associated injuries complicated by pediatric lower limb shaft fractures and the efficacy of surgical treatment using a flexible stainless-steel intramedullary Ender nail in children less than 15 years old. This is a retrospective review of 29 children younger than 15 years old who were diagnosed with femoral or tibial shaft fractures and treated using Ender nails from 2005 to 2016. Baseline data, etiology, associated injuries, fracture site and patterns, operative and post-operative assessment were evaluated. The average age of the patients was 9.0 years, and mean follow-up was 18.2 months. Eleven patients (79%) had associated injury. At the final follow up, six patients (43%) sustained complications associated with the insertion area of the nail. There was no evidence of deep infection or nonunion at either fracture site. The clinical results were excellent in 10 (67%) fractures, and good in 5 (33%) fractures, based on the modified Flynn criteria. Almost all patients with a femoral fracture had an associated injury including abdominal visceral injury, cerebral contusion or other fractures. This study indicated good clinical and functional outcomes. On the other hand, the minor complications rate was high. Nevertheless, elastic stable intramedullary nailing recently has become available in Japan, and a prospective and comparative study is needed.

Importance of the Application of Lean Manufacturing and Sustainable Manufacturing and Its Impact on Productivity and Quality in the Electronics Industry of Mexicali

An evaluation of use of lean and sustainable manufacturing tools was made, correlating them with the productivity and quality indices in an industry of the electronic sector located in the city of Mexicali. In this evaluated company, it was observed that some improper manufacturing methods was used and for this reason, generated a large amount of waste from electronic devices and electronic boards. This caused the productivity and quality indices to decrease, originating the need for extra time and with it unnecessary costs that devalued the prices of manufactured products, due to the competitiveness in the electronic industry sector evaluated. With the application of tools of lean manufacturing and sustainable manufacturing, the productivity and quality levels were increased and both overtime and unnecessary costs were reduced, achieving competitive prices in the evaluated industry. The installation method of electronic components with polarity in electronic boards was evaluated, due to the fact that a great diversity of products emerged from the automatic insertion area with defects, indicating reversed polarity, which should be solved, otherwise, short circuits could be generated or lack of electrical conductivity, in the manufactured products in their final process. This caused the manufactured products to not work properly, causing the presence of defective products and with it low levels of productivity and quality and economic losses. and It was detected that this occurred due to the lack of training of the operative personnel and the neglect of the operative workers of the automatic insertion area. In order to control this situation, as a methodological part, schematic models were developed to support the operational personnel in their activities in the automatic insertion area. This proposal with the schematic models developed for use in the electronics industry, where the research was made. The study was developed from 2018 to 2019.

New craniodental material of the extinct sigmodontine Olympicomys (Rodentia, Cricetidae) allows a discussion of its tribal affiliation

ABSTRACT We re-evaluate the tribal allocation of Olympicomys vossi, an extinct member of Sigmodontinae (Rodentia, Cricetidae). Originally described from fragmentary jaws, this taxon was considered as a Phyllotini. In light of new remains, including hemimandibles and for the first time an anterior part of the cranium with the upper dentition, we propose that it belongs to the Reithrodontini. The studied materials were collected in coastal outcrops of the Vorohué Formation (late Pliocene-early Pleistocene) south of Mar del Plata, Buenos Aires Province, Central Argentina. The reallocation of Olympicomys into Reithrodontini is based on the presence in this genus of several diagnostic characters of this tribe including a deeply excised anterior border of the zygomatic plate, a well-developed zygomatic spine, a shallow area of insertion of the anterior deep masseter muscle, a posteriorly depressed palate, labial accessory roots on upper and lower first molars, three-rooted lower third molar, and a bifid metaflexus on the second upper molar. Chukimys favaloroi and Dankomys vorohuensis, two other Pliocene Argentinean sigmodontines, are suggested as extinct reithrodontines. The restudy of Olympicomys provides elements to discuss the pattern of radiation of Sigmodontinae and to improve the chronostratigraphy of the coastal Neogene sedimentary succession of the Buenos Aires province.

The Schooling of black people in the Province of Pará in the end of nineteen century

O presente trabalho trata da escolarização do negro na província do Pará no final do século XIX. Para o desenvolvimento desta pesquisa, utilizamos a metodologia de natureza bibliográfica e documental. A partir das análises realizadas, podemos concluir que a educação paraense aos negros era excludente e que as ações do Governo em relação à escolarização foram marcadas por uma mínima atuação no quesito inserção escolar. No entanto, foi possível identificar a presença de negros nas iniciativas de instituições particulares. Tais iniciativas eram descontínuas, o que evidenciou a ausência da inserção escolar dos negros.

Effect of Percentage of Femoral Anterior Cruciate Ligament Insertion Site Reconstructed With Hamstring Tendon on Knee Kinematics and Graft Force

Background: Previous studies have stated that closely matching the size of the anterior cruciate ligament (ACL) insertion site footprint is important for biomechanical function and clinical stability after ACL reconstruction. However, the ACL varies widely regarding the area of femoral insertion, tibial insertion, and midsubstance of ACL, and reconstructing the insertion site area with a uniform diameter graft can result in a cross-sectional area that is greater than that of the midsubstance of the native ACL. Therefore, understanding the effect of relative graft size in ACL reconstruction on knee biomechanics is important for surgical planning. Purpose: To assess how the percentage of femoral insertion site affects knee biomechanics in single- and double-bundle ACL reconstruction. Study Design: Controlled laboratory study. Methods: A total of 14 human cadaveric knees were scanned with magnetic resonance imaging and tested using a robotic system under an anterior tibial load and a combined rotational load. In total, 7 knee states were evaluated: intact ACL; deficient ACL; single-bundle ACL reconstruction with approximate graft sizes 25% (small), 50% (medium), and 75% (large) of the femoral insertion site; and double-bundle reconstruction of approximately 50% (medium) and 75% (large) of the femoral insertion site, based on the ratio of the cross-sectional area of the graft to the area of the femoral ACL insertion site determined by magnetic resonance imaging. Results: Anterior tibial translation was not significantly larger than the intact state in single-bundle and double-bundle medium graft reconstructions (P > .05) and was significantly greater in the single-bundle small graft reconstruction (P < .05). Anterior knee translation in single-bundle medium graft and large graft reconstructions was not statistically different (P > .05). In contrast, the anterior tibial translation for double-bundle large graft reconstruction was significantly smaller than for double-bundle medium graft reconstruction at low flexion angles (P < .05). The single-bundle small graft force was significantly different from the intact ACL in situ force (P < .05). The graft force with double-bundle large reconstruction was significantly greater than that with the double-bundle medium reconstruction (P < .05) but was not significantly different from that of the intact ACL (P > .05). Conclusion: Knee biomechanics with a single-bundle small graft tended to be significantly different from those of the intact knee. In the kinematic and kinetic data for the single- and double-bundle medium graft reconstruction, only the anterior translation at full extension for the single-bundle reconstruction was significantly different (lower) from that of intact knee. This was a time zero study. Clinical Relevance: This study can provide surgeons with guidance in selecting the graft size for ACL reconstruction.

Measuring protein insertion areas in lipid monolayers by fluorescence correlation spectroscopy

Membrane insertion of protein domains is an important step in many membrane remodeling processes, for example, in vesicular transport. The membrane area taken up by the protein insertion influences the protein binding affinity as well as the mechanical stress induced in the membrane and thereby its curvature. To our knowledge, this is the first optical measurement of this quantity on a system in equilibrium with direct determination of the number of inserted protein and no further assumptions concerning the binding thermodynamics. Whereas macroscopic total area changes in lipid monolayers are typically measured on a Langmuir film balance, finding the number of inserted proteins without perturbing the system and quantitating any small area changes has posed a challenge. Here, we address both issues by performing two-color fluorescence correlation spectroscopy directly on the monolayer. With a fraction of the protein being fluorescently labeled, the number of inserted proteins is determined in situ without resorting to invasive techniques such as collecting the monolayer by aspiration. The second color channel is exploited to monitor a small fraction of labeled lipids to determine the total area increase. Here, we use this method to determine the insertion area per molecule of Sar1, a protein of the COPII complex, which is involved in transport vesicle formation. Sar1 has an N-terminal amphipathic helix, which is responsible for membrane binding and curvature generation. An insertion area of (3.4 ± 0.8) nm2 was obtained for Sar1 in monolayers from a lipid mixture typically used in COPII reconstitution experiments, in good agreement with the expected insertion area of the Sar1 amphipathic helix. By using the two-color approach, determining insertion areas relies only on local fluorescence measurements. No macroscopic area measurements are needed, giving the method the potential to also be applied to laterally heterogeneous monolayers and bilayers.

Morphology of the Ulnar Insertion of the Triangular Fibrocartilage Complex and Related Osseous Landmarks

In triangular fibrocartilage complex (TFCC) injuries, a foveal tear of the radioulnar ligament often requires surgery. Previous studies have suggested that surgeons should attach the TFCC to the center of the fovea. The TFCC and its insertion points are small structures, and few studies have reported details of the foveal insertion. This study aimed to clarify the morphology of the ulnar insertion of the TFCC and related osseous landmarks with 3-dimensional imaging. This study used 26 formalin-fixed cadavers. At the ulna, the TFCC was inserted from the fovea to the middle part of the ulnar styloid. After gross observation of the TFCC, the ulnar insertion was outlined using a 1.0-mm drill. We then created 3-dimensional images of the ulna using computed tomography and marked (with software) an outline of the foveal insertion of the TFCC. We measured the area and the long and short diameters of the TFCC insertion. The area of the TFCC insertion was 34 mm2 and positively correlated with the height of the ulnar styloid and the area of the ulnar head. The TFCC's highest point was 58% of the ulnar styloid height. The center of the TFCC insertion was 1.3 mm ulnar and 0.6 mm dorsal from the lowest point of the ulnar surface. The center of the TFCC insertion was slightly ulnar of the lowest point of the ulnar surface. This study revealed the center, the area, and the osseous relation of the ulnar insertion of the TFCC. When surgeons repair a TFCC foveal tear, they can find the anatomical center of the ulnar insertion efficiently and easily based on its osseous relationship.

Análisis morfométrico del frenillo labial superior durante el crecimiento y desarrollo del niño en edades 0 a 12 años

Objetivo: Establecer un análisis morfométrico del frenillo labial superior durante el crecimiento y desarrollo del niño en edades de 0 a 12 años en el Municipio Naguanagua periodo Marzo-Septiembre 2016. Materiales y Métodos: investigación de tipo descriptivo con un diseño de campo. Teniendo como objeto una población de 650 niños tomando como Muestra 260 sujetos, distribuidos de manera porcentual en, 31% Primera Infancia 23% Segunda Infancia y 46% Tercera Infancia. Se obtuvieron fotografías del frenillo, tomando 10 “landmark” (puntos de referencia) para la conformación de la estructura, siendo procesadas para su análisis con los Software, TpsDig2, Past, IMP7 y Morphoj. Resultados: la zona que presento mayor superposición en todos los grupos fue la de inserción gingival, mientras que la inserción labial presento mayor variación, en cuanto a 1 Residente del Postgrado de Odontopediatría, Universidad de Carabobo. 2 Odontopediatra UC. Docente del Postgrado de Odontopediatría U.C. y docente de Pregrado facultad de Odontología U.C. 3 PhD, en Entomología, Docente de la Universidad de Ikiam Ecuador. la deformación de la estructura en todas las etapas hubo desarrollo en sentido horizontal en la inserción labial. La medida promedio del frenillo labial superior se estableció entre 11 a 13mm, ±1-2mm de desviación. La inserción gingival a la papila interincisal se presentó una medida promedio 1 a 3 mm. ±1 mm. Conclusiones: el frenillo labial superior al nacer es fisiológicamente tectolabial, presentara un desarrollo de 1 a 2mm durante el 1er año de vida en su zona de inserción gingival exclusivamente, manteniéndose estable sin reposicionarse ni modificarse en longitud hasta la adolescencia, por lo que al realizar el análisis Morfométrico del frenillo labial superior en todos tipos de dentición dicha estructura presento similitudes indicándonos su estabilidad en las diferentes edades del infante.

IS THE "U-SIGN" RADIOLOGIC FEATURE OF A POSTERIOR CRUCIATE LIGAMENT TIBIAL AVULSION FRACTURE?

ABSTRACTObjective: By analyzing our cases of posterior cruciate ligament (PCL) tibial avulsion fracture, we noted that a U-shaped image was present in the anteroposterior plain radiographs view of the affected knee, even in cases where the profile view of the knee had been inconclusive as to tibial PCL avulsion fracture, a “hidden” fracture. Therefore, we aimed to investigate whether there was an anatomical correlation between this radiological U sign and the tibial insertion of the PCL and to ascertain the intra- and inter-rater reliability of this sign in clinical practice.Methods: The data of the widths and heights area of the PCL tibial insertion area, and the U sign area were measured and compared to the largest width of the tibia. Two moreover, the reliability and reproducibility of this imaging were analyzed.Results: The areas height of the U-sign area and the anatomical insertion area of the posterior cruciate ligament showed no difference, and both were topographically located in the two central quarters of the proximal end of the tibia. The radiographic assessment showed excellent Kappa agreement rates between interobserver and intraobserver, with high reliability and reproducibility.Conclusion: The U sign is a radiographic feature of PCL tibial avulsion fracture seen on the radiograph AP view, there is a high association between the ratios of the U-sign area height in the X-ray and the anatomical height of the PCL tibial insertion site MRI with the largest width of the proximal tibia. The radiographic U sign showed excellent rates of interobserver and intraobserver agreement with Kappa values higher than 0.8. Level of Evidence IV; Dignostic Studies - Investigating a Diagnostic Test.

Insectivory leads to functional convergence in a group of Neotropical rodents.

The mandible of vertebrates serves as insertion area for masticatory muscles that originate on the skull, and its functional properties are subject to selective forces related to trophic ecology. The efficiency of masticatory muscles can be measured as mechanical advantage on the mandible, which, in turn, has the property of correlating with bite force and shape. In the present work, we quantify the mechanical advantage of the mandible of akodontine rodents, which present a diverse radiation of insectivorous specialists, to assess their relationship to the estimated bite force and diet. We also tested the degree of morphofunctional convergence in response to insectivory on the group. We found the mechanical advantages to be convergent on insectivorous species, and associated with the estimated bite force, with higher mechanical advantages in species with a stronger bite and short, robust mandibles and lower mechanical advantages in insectivorous species with weaker bites and more elongated, dorso-ventrally compressed mandibles. Insectivorous species of Akodontini are functional specialists for the consumption of live prey and may exploit the resources that shrews, moles and hedgehogs consume elsewhere.

Effect of mass and habitat on the shape of limb long bones: A morpho-functional investigation on Bovidae (Mammalia: Cetartiodactyla).

Limb long bones are essential to an animal's locomotion, and are thus expected to be heavily influenced by factors such as mass or habitat. Because they are often the only organs preserved in the fossil record, understanding their adaptive trends is key to reconstructing the paleobiology of fossil taxa. In this regard, the Bovidae has always been a prized group of study. This family is extremely diverse in terms of both mass and habitat, and it is expected that their bones will possess adaptations to both factors. Here, we present the first 3D geometric morphometric study focusing on bovid limb long bones. We used anatomical landmarks as well as curve and surface sliding semi-landmarks to accurately describe the stylopod and zeugopod bones. We included 50 species from ten of the twelve currently recognized tribes of bovids, ranging from 4.6 to 725kg, and living in open plains, forests, mountains, or anywhere in-between. Shape data were correlated with the mean mass of the species and its habitat, even when taking into account the phylogenetic history of our sample. Bones pertaining to heavy species are more robust, adapted for a better repartition of stronger forces. Articulations are especially affected, being proportionally much larger in heavier species. Muscle insertion areas are unevenly affected. Insertion areas of muscles implied in body support and propulsion show a strong increase in their robustness when compared to insertion areas of muscles acting on the limb mostly when it is off the ground. Habitat influences the shape of the humerus, the radius-ulna, and the femur, but not of the tibia, whether the phylogeny is taken into account or not. Specific habitats tend to be associated with particular features on the bones. Articulations are proportionally wider in open-habitat species, and the insertion areas of muscles involved in limb extension and propulsion are wider, reflecting the fact that open habitat species are more cursorial and rely on fast running to avoid predators. Forest and mountain species generally present similar adaptations for increased manoeuvrability, such as a round femoral head, and generally have more gracile bones.

Evaluating the morphological features of the lateral pterygoid insertion into the medial surface of the condylar process.

ObjectiveThe lateral pterygoid is vital in coordinating multidimensional jaw movements. Since a vector in three‐dimensional (3D) space is defined by two 3D points, the role of the lateral pterygoid in 3D jaw movements is defined by its origin and insertion. Reportedly, the lateral pterygoid is inserted into not only the pterygoid fovea but also into the medial surface of the condylar process. The objective was to investigate the morphological features of the region of the lateral pterygoid that inserted into the medial surface of the condylar process.Material and MethodsTen head halves of seven cadaveric donors were analyzed. In all specimens, the insertion area on the medial surface of the condylar process was measured based on microcomputed tomography images. Muscle fibers were separated into ≥50 small bundles, and positional relationships between the origins and insertions were investigated.ResultsOverall, 28.8 ± 5.0% of the insertion area of the lateral pterygoid was situated on the medial surface of the condylar process. Moreover, muscle fiber arrangement revealed that origins of the muscle bundles inserting into the medial surface in seven specimens posteriorly occupied the lateral plate of the pterygoid process longitudinally, whereas those in three specimens mainly occupied the posteroinferior portion.ConclusionsMuscle bundle inserting on the medial surface of the condylar process had a broad insertion area and a distinct origin on the posterior region of the lateral plate of the pterygoid process. This muscle bundle could act as one of the significant subunits within the lateral pterygoid. Therefore, anatomical coordination mechanisms underlying jaw movement cannot be elucidated without considering this subunit.