Bone Shape Research Articles

Transfer Learning-Based Osteoporosis Classification Using Simple Radiographs

Osteoporosis is a condition that affects the entire skeletal system, resulting in decreased density of bone mass and the weakening of bone tissue's micro-architecture. This leads to weaker bones that are more susceptible to fractures. Detecting and measuring bone mineral density has always been a critical area of focus for researchers in the diagnosis of bone diseases such as osteoporosis. However, existing algorithms used for osteoporosis diagnosis encounter challenges in obtaining accurate results due to X-ray image noise and variations in bone shapes, especially in low contrast conditions. Therefore, the development of efficient algorithms that can mitigate these challenges and improve the accuracy of osteoporosis diagnosis is essential. In this research paper, a comparative analysis was conducted Assessing the accuracy and efficiency of the latest deep learning CNN model, such as VGG16, VGG19, DenseNet121, Resnet50 and InceptionV3 in detecting to Classify Normal and Osteoporosis cases. The study employed 830 X-ray images of Spine, Hand, Leg, Knee, and Hip, comprising of Normal (420) and Osteoporosis (410) cases. Various performance metrics were utilized to evaluate each model, and the findings indicate that DenseNet121 exhibited superior performance with an accuracy rate of 93.4% with Achieving an error rate of 0.07 and a validation loss of only 0.57 in comparison with other models considered in this study.

Herbarium Media: Enhancing Science Learning Outcomes for Grade 4 Students on Leaf Bone Shape

This study aimed to investigate the effectiveness of utilizing herbarium media in improving science learning outcomes for fourth-grade students. The research employed a quantitative approach, specifically a pre-experimental design with a one-group pretest-posttest design method. The independent variable (X) was the experimental method using herbarium media, while the dependent variable (Y) was student learning outcomes. The study was conducted at SDN Gelam 1, with a sample size of 25 students (14 males and 11 females) from class IV. Data analysis was performed using a t-test. The results indicated that the use of dried plant herbarium media significantly influenced the learning outcomes of the students, with a significant value of 0.048 (<0.05). Consequently, the null hypothesis (H0) was rejected, and the alternative hypothesis (H1) was accepted. The application of herbarium media demonstrated an 83.8% improvement in the cognitive learning outcomes of fourth-grade students, as it facilitated a better understanding of the subject matter. These findings suggest that employing the herbarium media experimental method can effectively enhance science learning outcomes for fourth-grade students at Gelam 1 Elementary School.
 Highlights: 
 
 
 Herbarium media improves science learning: The use of herbarium media enhances the science learning outcomes of grade 4 students, providing a valuable resource for studying leaf bone shapes and connecting it to the surrounding environment.
 
 
 Experimental approach and design: The study employs a quantitative experimental approach
 
 Significance of learning media: Limited learning media can hinder student absorption in learning. The research highlights the importance of utilizing effective learning resources, such as herbarium media, to enhance student engagement and understanding in science education.
 
 Keywords: Herbarium media, science learning outcomes, grade 4 students, elementary schools, leaf bone shape

Radiation attenuation properties of chemically prepared MgO nanoparticles/HDPE composites

Sheets of high-density polyethylene (HDPE) loaded with magnesium oxide in micro and nano were synthesized with different weight percentages of micro-MgO (0,5,10,20 and 30% by weight) and nano-MgO (5 and 30%) and shaped in form of disc and dog bone shape. The morphological, mechanical, and attenuation characteristics of each concentration were determined. The linear attenuation coefficients (LAC) of the prepared discs were calculated using a well-calibrated scintillation detector and five standard gamma-ray point sources (241Am, 133Ba, 137Cs, 60Co and 152Eu). The LAC was theoretically calculated for HDPE/micro-MgO composites using XCOM software. A good agreement between the theoretical and experimental results was observed. The comparison between micro and nano-MgO as a filler in HDPE was evaluated. The results proved that the loaded nano-MgO in different proportions of HDPE produced greater attenuation coefficients than its micro counterpart. The addition of nano MgO with different weight percentage led to a significant improvement in the mechanical properties of HDPE, the ultimate force and ultimate stress increased as the concentration of nano MgO increased, and the young modulus of HDPE also increased with increasing concentration of micro and nano MgO.

An analysis of the maxillary beak shape variation between 2 pure layer lines and its relationship to the underlying premaxillary bone, feather cover, and mortality

Beak shape varies considerably within and between intact-beak laying hens, and aspects of beak shape appear to be heritable. As an alternative to beak treatment (an effective method of reducing damage from severe feather pecking (SFP)), this variation could be used to genetically select hens whose beak shapes are less apt to cause damage. To be able to select certain phenotypes, the beak shape variation that exists within laying hen flocks must first be characterized. The objectives of this study were to 1) describe the maxillary beak shape variation in 2 pure White Leghorn layer lines with intact beaks using geometric morphometrics to analyze images, and 2) examine the beak shape's relationship to the premaxillary bone, feather cover, and mortality. A lateral head image was taken of each hen (n=710), and 20 landmarks were placed along each image's dorsal and ventral margins of the maxillary beak. Landmark coordinates were standardized by Procrustes superimposition, and the covariation was analyzed by principal components analysis and multivariate regression. Feather cover was scored at 3 ages and mortality was monitored throughout the production cycle. Three principal components (PCs) explained 83% of the maxillary beak shape variation and the first PC partially separated the 2 lines. Maxillary beak shapes ranged from long and narrow with pointed tips to short and wide with more curved tips. Moderate correlations were found between the maxillary beak and premaxillary bone shape (rs=0.44) and size (rs=0.52). Line A hens had better feather cover than Line B at all ages. Line A hens also had less total and cannibalism-related mortality than Line B (10.7 and 0.4% vs. 16.7 and 2.4%, respectively). Beak shape may be one factor contributing to the observed differences in feather cover and mortality. The results suggest that distinct maxillary beak phenotypes within each line could be selected to help reduce SFP damage and improve bird welfare.

Increasing muscle contractility through low-frequency stimulation alters tibial bone geometry and reduces bone strength in mdx and dko dystrophic mice.

Duchenne muscular dystrophy (DMD) is a severe muscle wasting disease caused by mutations or deletions in the dystrophin gene, for which there remains no cure. As DMD patients also develop bone fragility because of muscle weakness and immobilization, better understanding of the pathophysiological mechanisms of dystrophin deficiency will help develop therapies to improve musculoskeletal health. Since alterations in muscle phenotype can influence bone structure, we investigated whether modifying muscle contractile activity through low-frequency stimulation (LFS) could alter bone architecture in mouse models of DMD. We tested the hypothesis that increasing muscle contractile activity could influence bone mass and structure in dystrophin-deficient (mdx) and dystrophin- and utrophin-deficient (dko) dystrophic mice. Tibial bone structure in dko mice was significantly different from that in mdx and wild-type (C57BL/10) control mice. Effects of LFS on bone architecture differed between dystrophic and healthy mice, with LFS thinning cortical bone in both dystrophic models. Bone mass was maintained in LFS-treated healthy mice, with a reduced proportion of high-density bone and concomitant increase in low-density bone. LFS-treated dko mice exhibited a net deficit in cortical thickness and reduced high-density bone but no equivalent increase in low-density bone. These alterations in bone structure and mineral density reduced mechanical strength in mdx and dko mice. The findings reveal that muscle activity can regulate bone mass, structure, mineral accrual, and strength, especially in the context of dystrophin and/or utrophin deficiency. The results provide unique insights into the development of bone fragility in DMD and for devising interventions to improve musculoskeletal health.NEW & NOTEWORTHY Patients with Duchenne muscular dystrophy (DMD) develop bone fragility because of muscle weakness and immobilization. We investigated whether increasing muscle contractile activity through low-frequency stimulation (LFS) could alter bone architecture in dystrophin-deficient (mdx) or dystrophin- and utrophin-deficient (dko) mouse models of DMD. Chronic LFS reduced tibial diaphysis cross sections in mdx and dko mice, without affecting bone shape in healthy mice. LFS affected the distribution of bone mineral density across all phenotypes, with the magnitude of effect being dependent on disease severity.

Femoral Metastasis in Bone Mineral Densitometry

A 50-year-old female patient referred by the Department of Breast and Thyroid Surgery was recommended for orthopedic surgery because a lesion-like herniation pit was found in the left proximal femur in bone mineral densitometry (BMD). She was later diagnosed with bone metastasis based on a biopsy in orthopedic surgery. Pelvic X-ray and left thigh MRI were performed. An intramedullary nail was later inserted. The BMD is a diagnostic method based on numerical values, so it is inevitable that the bone shape may be neglected. This case report illustrates the importance of the radiotechnologist's observation of the bone shape. In our patient, it led to beneficial treatment.

Comparing bone shape models from deep learning processing of magnetic resonance imaging to computed tomography-based models

The purpose of this study was to develop a deep learning approach to automatically segment the scapular bone on magnetic resonance imaging (MRI) images and to compare the accuracy of these three-dimensional (3D) models with that of 3D computed tomography (CT). Fifty-five patients with high-resolution 3D fat-saturated T2 MRI were retrospectively identified. The underlying pathology included rotator cuff tendinopathy and tears, shoulder instability, and impingement. Two experienced musculoskeletal researchers manually segmented the scapular bone. Five cross-validation training and validation splits were generated to independently train two-dimensional (2D) and 3D models using a convolutional neural network approach. Model performance was evaluated using the Dice similarity coefficient (DSC). All models with DSC > 0.70 were ensembled and used for the test set, which consisted of four patients with matching high-resolution MRI and CT scans. Clinically relevant glenoid measurements, including glenoid height, width, and retroversion, were calculated for two of the patients. Paired t-tests and Wilcoxon signed-rank tests were used to compare the DSC of the models. The 2D and 3D models achieved a best DSC of 0.86 and 0.82, respectively, with no significant difference observed. Augmentation of imaging data significantly improved 3D but not 2D model performance. In comparing clinical measurements of 3D MRI and CT, there was a mean difference ranging from 1.29 mm to 3.46 mm and 0.05° to 7.47°. We have presented a fully automatic, deep learning-based strategy for extracting scapular shape from a high-resolution MRI scan. Further developments of this technology have the potential to allow for surgeons to obtain all clinically relevant information from MRI scans and reduce the need for multiple imaging studies for patients with shoulder pathology.

4D Printing of Personalized-Tunable Biomimetic Periosteum with Anisotropic Microstructure for Accelerated Vascularization and Bone Healing.

An ideal biomimetic periosteum is expected to wrap various bone surfaces to orchestrate an optimal microenvironment for bone regeneration, including facilitating local vascularization, recruiting osteoblasts, and mineralizing the extracellular matrix (ECM). To mimic the role of the natural periosteum in promoting bone repair, a 4D printing technique to inlay aligned cell sheets on shape-shifting hydrogel is used, containing biophysical signals and spatially adjustable physical properties, for the first time. The outer hydrogel layer endows the biomimetic periosteum with the ability to digitally coordinate its 3D geometry to match the specific macroscopic bone shape to maintain a bone healing microenvironment. The inner aligned human mesenchymal stem cells (hMSCs) layer not only promotes the migration and angiogenesis of co-cultured cells but also exhibits excellent osteogenic differentiation properties. In vivo experiments show that apart from morphing preset shapes as physical barriers, the aligned biomimetic periosteum can actively facilitate local angiogenesis and early-stage osteogenesis. Altogether, this present work provides a novel route to construct a personalized biomimetic periosteum with anisotropic microstructure by introducing a tunable shape to maintain the bone reconstruction microenvironment and this strategy can be extended to repair sophisticated bone defects.

The transcriptional state and chromatin landscape of cichlid jaw shape variation across species and environments.

Adaptive phenotypes are shaped by a combination of genetic and environmental forces, but how they interact remains poorly understood. Here, we utilize the cichlid oral jaw apparatus to better understand these gene-by-environment effects. First, we employed RNA-seq in bony and ligamentous tissues important for jaw opening to identify differentially expressed genes between species and across foraging environments. We used two Lake Malawi species adapted to different foraging habitats along the pelagic-benthic ecomorphological axis. Our foraging treatments were designed to force animals to employ either suction or biting/scraping, which broadly mimic pelagic or benthic modes of feeding. We found a large number of differentially expressed genes between species, and while we identified relatively few differences between environments, species differences were far more pronounced when they were challenged with a pelagic versus benthic foraging mode. Expression data carried the signature of genetic assimilation, and implicated cell cycle regulation in shaping the jaw across species and environments. Next, we repeated the foraging experiment and performed ATAC-seq procedures on nuclei harvested from the same tissues. Cross-referencing results from both analyses revealed subsets of genes that were both differentially expressed and differentially accessible. This reduced dataset implicated notable candidate genes including the Hedgehog effector, KIAA0586 and the ETS transcription factor, etv4, which connects environmental stress and craniofacial morphogenesis. Taken together, these data provide novel insights into the epigenetic, genetic and cellular bases of species- and environment-specific bone shapes.

Treatment of Sanders typeⅡto Ⅲ calcaneal fractures with percutaneous reduction and minimally invasive calcaneal screw fixation

To investigate clinical effect of percutaneous reduction combined with internal fixation of calcaneal nail in treating Sanders typeⅡto Ⅲ calcaneal fractures. From July 2017 to August 2019, clinical data of 98 patients with Sanders typeⅡto Ⅲ calcaneal fractures treated were retrospectively analyzed, and divided into observation group and control group according to different surgical methods. In observation group, there were 35 males and 21 females, aged from 23 to 58 years old with an average of (34.50±7.81) years old;29 patients with Sanders typeⅡand 27 patients with Sanders type Ⅲ;30 patients on the left side and 26 patients on the right side;the time from fracture to operation ranged from 1 to 4 days with an average of (3.45±0.54) days;and treated with percutaneous reduction combined with internal fixation of calcaneal nail system. In control group, there were 25 males and 17 females, aged from 25 to 60 years old with an average of (35.27±7.64) years old;23 patients with Sanders type Ⅱ and 19 patients with Sanders type Ⅲ;24 patients on the left side and 18 patients on the right side;the time from fracture to operation ranged from 2 to 5 days with an average of (3.42±0.62) days;and treated with open reduction and internal fixation. Operation time, blood loss, hospital stay, fracture healing time, and postoperative visual analogue scale (VAS) at 1 day, preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Böhler angle, Gissane angle and calcaneus width, and postoperative complications were compared between two groups. All patients were followed up from 13 to 18 months with an average of (15.6±2.2) months. There were significant differences in operation time, blood loss, hospital stay, fracture healing time and postoperative VAS at 1 day between two groups (P<0.05). There was statistical difference in postoperative AOFAS score at 12 months between two groups (P<0.05), and AOFAS score at 12 months after operation was higher than that before operation (P<0.05). According to AOFAS score, 21 patients got excellent result, 30 good and 5 moderate in observation group, and 10 excellent, 22 good, 7 moderate and 3 poor in control group, which had statistical difference between two groups (P<0.05). Postoperative Böhler angle, Gissane angle and calcaneus width at 6 months were better than that before operation between two groups(P<0.05). One patient in observation and 20 patients in control group occurred skin numbness after operation, and 14 patients occurred skin necrosis in control group, there were obvious difference between two groups(P<0.01). Compared with open reduction and internal fixation, percutaneous reduction combined with internal fixation system in treating Sanders typeⅡto Ⅲ calcaneal fractures is feasible for fracture repair without waiting for foot deswelling, which could accurately restore normal shape and position of the fractured heel bone, completely eliminate fracture malunion, and reduce postoperative complications. Therefore, it could shorten operation time, hospital stay, fracture healing time, reduce amount of blood loss, promote postoperative recovery, and less complications, high safety, which could be used as a choice of orthopedic surgery for foot and ankle trauma.

Osteoblastic RAR Inhibition Causes VAD-Like Craniofacial Skeletal Deformity

Retinoid signaling disorders cause craniofacial deformity, among which infants with maternal vitamin A deficiency (VAD) exhibited malformation of the eye, nose, palate, and parietal and jaw bone. Previous research uncovered the pathogenesis of eye defect and cleft palate of VAD in mice, but the studies on craniofacial skeletal deformity met obstacles, and the cell/lineage and underlying mechanism remain unclear. The retinoic acid receptor (RAR) is the key transcription factor in retinoid signaling, but individual knockout cannot simulate pathway inhibition. Here, we conditionally expressed dominant-negative RARα mutation (dnRARα) in osteoblasts to specifically inhibit the transcription activity of RAR in mice, which mimics the craniofacial deformities caused by VAD in clinical cases: hypomineralization of cranial bones, mandibular deformity, and clavicular hypoplasia. Furthermore, we performed 3-dimensional reconstruction based on micro–computed tomography and confirmed the abnormalities in the shape, size, and ossification of craniofacial bones due to osteoblastic RAR inhibition. Histological analysis indicated that inhibition of RAR in osteoblasts impaired both bone formation and bone resorption, which was confirmed by transcriptome sequencing of the calvaria. Furthermore, mechanism investigation showed that inhibition of RAR in osteoblasts directly decreased osteoblast differentiation in a cell-autonomous manner by impairing osteogenic gene transcription and also inhibited osteoclast differentiation via osteoblast–osteoclast crosstalk by impairing Rankl transcription. In summary, osteoblastic RAR activity is critical to craniofacial skeletal development, and its dysfunction leads to skeletal deformities mimicking VAD craniofacial defects, providing a new insight for VAD pathogenesis.

The Corticosteroid Meniscectomy Trial of Extended-Release Triamcinolone Injection After Arthroscopic Partial Meniscectomy: Protocol for a Double-Blind Randomized Controlled Trial.

Meniscal tear in older adults often accompanies knee osteoarthritis and is commonly treated with arthroscopic partial meniscectomy (APM) when patients have persistent pain after a trial of physical therapy. Cross-sectional evidence suggests that synovitis is associated with baseline pain in this patient population, but little is known about the relationship between synovitis and postoperative recovery or progression of knee osteoarthritis. Intra-articular extended-release triamcinolone may reduce inflammation and thereby improve outcomes and slow disease progression. This article presents the rationale behind the Corticosteroid Meniscectomy Trial (CoMeT) and describes its study design and implementation strategies. Randomized controlled trial. CoMeT is a 2-arm, 3-center, randomized placebo-controlled trial designed to establish the clinical efficacy of extended-release triamcinolone administered via intra-articular injection immediately after APM. The primary outcome is change in Knee injury and Osteoarthritis Outcome Score Pain subscore at 3-month follow-up. Synovial biopsy, joint fluid aspirate, and urine and blood sample analyses will examine the associations between various objective measures of baseline inflammation and pre- and postoperative outcome measures and clinical responses to triamcinolone intervention. Quantitative 3-T magnetic resonance imaging will evaluate cartilage and meniscal composition and 3-dimensional bone shape to detect early joint degeneration. We discuss methodologic innovations and challenges. To our knowledge, this is the first randomized double-blind clinical trial that will analyze the effect of extended-release triamcinolone acetonide on pain, magnetic resonance imaging measures of structural change and effusion/synovitis, soluble biomarkers, and synovial tissue transcriptomics after APM.

Preoperative Prediction of Optimal Femoral Implant Size by Regularized Regression on 3D Femoral Bone Shape

Preoperative determination of implant size for total knee arthroplasty surgery has numerous clinical and logistical benefits. Currently, surgeons use X-ray-based templating to estimate implant size, but this method has low accuracy. Our study aims to improve accuracy by developing a machine learning approach that predicts the required implant size based on a 3D femoral bone mesh, the key factor in determining the correct implant size. A linear regression framework imposing group sparsity on the 3D bone mesh vertex coordinates was proposed based on a dataset of 446 MRI scans. The group sparse regression method was further regularized based on the connectivity of the bone mesh to enforce neighbouring vertices to have similar importance to the model. Our hypergraph regularized group lasso had an accuracy of 70.1% in predicting femoral implant size while the initial implant size prediction provided by the instrumentation manufacturer to the surgeon has an accuracy of 23.1%. Furthermore, our method was capable of predicting the implant size up to one size smaller or larger with an accuracy of 99.1%, thereby surpassing other state-of-the-art methods. The hypergraph regularized group lasso was able to obtain a significantly higher accuracy compared to the implant size prediction provided by the instrumentation manufacturer.

Tracking patellar osteophytes to detect osteoarthritis

ABSTRACT The presence of bone spurs (osteophytes) in knee-joints provides an indication of the onset of osteoarthritis and related deformities in patients. The shape of the patella bone at knee-joint undergoes various changes with the advancement of the disease, which may be discerned accurately from X-ray images. The main objective of this work is to identify the presence of osteophytes in the patella bone of knee-joint. Geometric features are extracted that highlight protrusions present on the bone surface from lateral views of X-ray images. The patella region is extracted from the image by performing texture-based segmentation followed by adaptive thresholding. Characteristic features are extracted from the segmented patella using derived novel measures based on differential chain code of the contour and convex hull. Linear support vector machine is used to classify diseased test-cases from healthy ones using the extracted features. Experimental results demonstrate the capability of the proposed image-analysis tool for detecting osteoarthritis with average accuracy of 93.75%.

Acoustic Emission Characteristics of Different Porcine Bones Under Loading

In order to obtain the acoustic emission (AE) characteristics of fresh porcine bones of different parts under loadings, the fresh porcine femur, scapula and vertebra were investigated by using a compression testing machine and the AE instrument, respectively. The results show that the compression curve of the porcine bones has an obvious dependence on the shape of the porcine bones, and cracks can be observed with an increase of loading. Some obvious inflection points can also be found on the compression curve. The AE parameters of porcine bones under loading agrees well with the variation of the inflection points. The porcine femur exhibits the most obvious variation of AE parameters with an increase of loading and has the largest frequency band of 20--140~kHz and a dominant frequency value of 65 kHz. However, the AE energy of the scapula vertebra is weak under loading effects, and the vertebra has the smallest dominant frequency value of 25 kHz.

3D shape reconstruction of the femur from planar X-ray images using statistical shape and appearance models

Major trauma is a condition that can result in severe bone damage. Customised orthopaedic reconstruction allows for limb salvage surgery and helps to restore joint alignment. For the best possible outcome three dimensional (3D) medical imaging is necessary, but its availability and access, especially in developing countries, can be challenging. In this study, 3D bone shapes of the femur reconstructed from planar radiographs representing bone defects were evaluated for use in orthopaedic surgery. Statistical shape and appearance models generated from 40 cadaveric X-ray computed tomography (CT) images were used to reconstruct 3D bone shapes. The reconstruction simulated bone defects of between 0% and 50% of the whole bone, and the prediction accuracy using anterior–posterior (AP) and anterior–posterior/medial–lateral (AP/ML) X-rays were compared. As error metrics for the comparison, measures evaluating the distance between contour lines of the projections as well as a measure comparing similarities in image intensities were used. The results were evaluated using the root-mean-square distance for surface error as well as differences in commonly used anatomical measures, including bow, femoral neck, diaphyseal–condylar and version angles between reconstructed surfaces from the shape model and the intact shape reconstructed from the CT image. The reconstructions had average surface errors between 1.59 and 3.59 mm with reconstructions using the contour error metric from the AP/ML directions being the most accurate. Predictions of bow and femoral neck angles were well below the clinical threshold accuracy of 3°, diaphyseal–condylar angles were around the threshold of 3° and only version angle predictions of between 5.3° and 9.3° were above the clinical threshold, but below the range reported in clinical practice using computer navigation (i.e., 17° internal to 15° external rotation). This study shows that the reconstructions from partly available planar images using statistical shape and appearance models had an accuracy which would support their potential use in orthopaedic reconstruction.

4DFA: Four-Dimensional Full-Anatomy Reconstruction of Individualized Digital Human Models Based on Motion Videos

Reconstructing personalized models of the human body is a key step for digital twin modeling of sports motion. There have been many studies reconstructing the body surface models based on video sequences, but these algorithms lack the modeling of internal structures (bones, muscles, blood vessels, etc.). Some researchers map internal organ structures into the 3D point cloud scanning of the body surface, but such mapping does not guarantee realistic tissue deformation and is not developed for video processing. This paper focuses on the video-based reconstruction of a personalized full-anatomy digital model in sports motion. Our method creates a four-dimensional (4D) model of the moving process composed of the 3D models of each time moment. We first use a deep network to regress the body surface of each time point and then estimate the internal structures by registering a previously constructed deformable human anatomy atlas to the body surfaces. To mimic realistic internal structure deformation, we applied articulated linear transform to the bony structures to avoid bone shape distortion and applied smooth nonlinear transform to the soft tissue to mimic the motion deformation. We also developed an intersection removal method to prevent the possible intersection between bones and soft tissues during the deformation. Our method is tested with athletes' sports videos and automatically generates full-anatomy motion models which cannot be achieved by previous methods. Our method also surpasses the existing video-based body surface modeling method by providing additional internal structures. The 4D human motion model constructed by our method is useful in sports modeling, biomechanics simulation, wearable device design, etc.

A saw-toothed eel †Serrivomer glehni sp. nov. from the Miocene of Sakhalin Island, north-western Pacific

ABSTRACT †Serrivomer glehni, a new species of the Neogene saw-toothed eel (Anguilliformes, Serrivomeridae) is described based on the 55 specimens from the Middle–Upper Miocene Kurasi Formation of Sakhalin Island, Russia. This is the third record of fossil saw-toothed eels since the recovery of partial skeletons from the Miocene of Japan and Italy. The new species demonstrates close similarity to the extant Serrivomer species in overall body form and shape of separate bones and their complexes. The new species is characterized by the “longidentatus” type of vomerine dentition and by a single branchiostegal ray protruding beyond the hyoid bar, which suggests a close affinity to the modern S. sector. It can be reliably distinguished from all other species of Serrivomer by its lower number of vertebrae (134 vs. 140–172) and its larger cleithrum, which is positioned under the seventh instead of the eighth vertebral centrum. http://zoobank.org/urn:lsid:zoobank.org:pub:50673E06-602C-4CA1-8CFF-AD992BCAEBED

Syncranial osteology of the Nine-Banded Armadillo, &lt;em&gt;Dasypus novemcinctus&lt;/em&gt;, from south Brazil

Several aspects of the bone morphology of armadillos have been investigated and used as taxonomic bases. The nined-banded armadillo, Dasypus novemcinctus, is the species of the genus that has the largest geographical distribution. Although is the most well-known armadillo species in its biology, skeletal studies are scarce and its original description is not detailed to permit accurate taxonomic revision including specimens from Southern end of Brazil. The objective of the present work was to provide a complete description of the synchranium of specimens from Pampa biome including areas located at south of Rio Grande do Sul State, Brazil. The bony elements were described in detail on the basis of thirty-two specimens prepared specifically for this study. In general, the shape of bones remained morphologically similar between adults of both sexes. The studied specimens differed morphologically from those of previous studies and from more northern regions. Differences were verified in the lateral border of the palatine bone, shape of the pterygoids bones,shape of the coanas, outline of foramen Magnum and of Tentorial process. The results obtained generated evidences that may contribute to future morphological and taxonomical studies including animals from Southern Brazil.

Management of Curved Bone Defects in the Anterior Maxilla Using Bone Bending via a Kerfed Khoury Split Bone Block Technique.

The loss of teeth causes inevitable resorption of the alveolar bone. In the anterior arches, the curved anatomy further adds to the challenge of rehabilitation. These areas often require the shaping of membranes and multiple bone blocks through complex surgery to compensate for the curvature. The split bone block technique (SBBT) has been successfully used in complicated cases. However, the inability to create curves from the blocks means that larger quantities of bone or membranes are needed to compensate for this. Bone bending based on an ancient woodbending technique known as kerfing is proposed to shape rigid SBB plates to recreate the natural anatomy of anterior arches. Three patients presenting with bone destruction of the anterior maxilla underwent bone augmentation before implant placement using the SBBT combined with kerfing. The plates were successfully bent to the shape of each maxilla without any deleterious effects. All bone grafts healed uneventfully, and the bone curvature was successfully reconstructed. No complications were reported. Implant placement took place after 4 months and definitive restorations after 7 to 9 months. Clinical and radiographic assessments were performed at 1 year. Full customization of autogenous bone plates was possible through kerfing. This approach resulted in an ideal bone curve and shape in the facial and palatal aspects of the anterior maxilla. In addition, it enabled ideal implant placement with reduced bone harvesting volumes and decreased the need for soft tissue augmentation to recreate the curved shape. This technique promoted close-fitting autologous osseous plates that followed the anatomical curvature of the anterior maxilla, leading to optimal healing and excellent regeneration of the ridge width. This principle can be valuable when dealing with complex anatomical defects. Int J Periodontics Restorative Dent 2023;43:203-210. doi: 10.11607/prd.6469.