Head Deformity Research Articles

Disruption in CYLC1 leads to acrosome detachment, sperm head deformity, and male in/subfertility in humans and mice

The perinuclear theca (PT) is a dense cytoplasmic web encapsulating the sperm nucleus. The physiological roles of PT in sperm biology and the clinical relevance of variants of PT proteins to male infertility are still largely unknown. We reveal that cylicin-1, a major constituent of the PT, is vital for male fertility in both mice and humans. Loss of cylicin-1 in mice leads to a high incidence of malformed sperm heads with acrosome detachment from the nucleus. Cylicin-1 interacts with itself, several other PT proteins, the inner acrosomal membrane (IAM) protein SPACA1, and the nuclear envelope (NE) protein FAM209 to form an ‘IAM–cylicins–NE’ sandwich structure, anchoring the acrosome to the nucleus. WES (whole exome sequencing) of more than 500 Chinese infertile men with sperm head deformities was performed and a CYLC1 variant was identified in 19 patients. Cylc1-mutant mice carrying this variant also exhibited sperm acrosome/head deformities and reduced fertility, indicating that this CYLC1 variant most likely affects human male reproduction. Furthermore, the outcomes of assisted reproduction were reported for patients harbouring the CYLC1 variant. Our findings demonstrate a critical role of cylicin-1 in the sperm acrosome–nucleus connection and suggest CYLC1 variants as potential risk factors for human male fertility.

The Effect of Vitamin D Deficiency as a Risk Factor of Early Fragmentation in Legg-Calve-Perthes Disease: A Prospective Study.

Legg-Calve-Perthes disease (LCPD) is a disorder involving the hips in young children of preschool and school-going age groups, more common in 4-8 years. The insufficient blood supply to the femoral head is the main reason behind various etiologic theories. Multiple factors affect the natural progression of the disease. The natural progression of the disease involves early avascular necrosis, fragmentation, reconstitution, and healed stages. In the fragmentation stage, the bony epiphysis begins to fragment, and the subchondral radiolucent zone (crescent sign) is the result of a subchondral stress fracture, which later on determines the extent of a necrotic fragment of the femoral head. These changes later contribute to changes in the shape of the femur head and the extent of deformity. As vitamin D plays a vital role in the onset of the fragmentation stage, we conducted a study to assess the effect of vitamin Ddeficiency as a risk factor for early fragmentation in Legg-Calve-Perthes disease. In our study, 50 patients aged 4-12 years were examined over three years and classified according to Catterall and Herring's lateral pillar classification; the length of the fragmentation stage and the vitamin D levelwere considered. A vitamin D level of less than 20 ng/mL was labeled as the deficient group, 20-30ng/mL as the insufficient group, and more than 30 ng/mL as the sufficient (normal) group. The critical fragmentation stage was significantly longer (more than 12 months) in vitamin D deficiency (34%), leading to a higher risk of deformity and extrusion of the femoral head, which led to higher rates of surgical intervention and containment procedures. The fragmentation stage is critical in the course of LCPD. Vitamin D levels play a vital role in predicting the prognostic of LCPD, and it should bemeasured in all patients of LCPD. Patients with normal vitamin D levels have a comparatively shorter fragmentation stage duration than patients with insufficient or deficient levels, leading to a lesser duration of femoral head damage.

How anatomic should anatomic total shoulder arthroplasty be? Evaluation of humeral head reconstruction with the best-fit circle

IntroductionHumeral implant designs for anatomic total shoulder arthroplasty (aTSA) focus on anatomic reconstruction of the articular segment. Likewise, the pathoanatomy of advanced glenohumeral osteoarthritis (GHOA) often results in humeral head deformity. We hypothesized the anatomic reconstruction of the humeral head in aTSA risks overstuffing the glenohumeral joint. Methods97 cases (52 females) of primary GHOA in patients treated with aTSA were evaluated. Preoperative computed tomography (CT) scans were used to classify glenoid morphology according to the Walch classification. Coronal plane images in the plane of the humerus were used to determine the anatomic perfect circle as described by Youderian et al. Humeral head thinning was determined as the distance from the center of rotation (COR) of the perfect circle to the nearest point along the humeral articular surface. aTSA was modeled with a predicted anatomic humeral head and a simulated 4 mm polyethylene glenoid component. The change in the position of the native humerus was determined. Wilcoxon Rank Sum tests were used to evaluate differences in humeral head thinning and humeral lateralization between monoconcave and biconcave glenoid morphologies. Spearman’s rank correlation coefficients were used to assess the relationship between humeral head thinning with preoperative active forward elevation and external rotation. ResultsThe mean radius of the perfect circle was 25.0±2.1 mm. There was a mean thinning of 2.4±2.0 mm (Range -1.7–8.3). Mean percent thinning of the humeral head was 9.4%±7.7%. The mean humeral lateralization was 6.4±2.0 mm. Humeral head thinning was not significantly associated with active forward elevation (r=-0.15, p=0.14) or active external rotation (r= -0.12, p=0.25). There were no significant differences in the percentage of humeral head thinning (p=0.324) or humeral lateralization (p=0.350) between concentric and eccentric glenoid wear patterns ConclusionsUtilization of the perfect circle as a guide in aTSA may risk excessive lateralization of the humerus and overstuffing the glenohumeral joint. This may have implications for subscapularis repair and healing, as well as glenoid implant and rotator cuff longevity. These findings call into question whether recreation of normal glenohumeral anatomy in aTSA is appropriate for all patients. Humeral head reconstruction in aTSA should account for glenohumeral joint volume and soft tissue contracture.

Missed Monteggia Injuries in Children and Adolescents: A Treatment Algorithm.

Monteggia injuries are rare childhood injuries. In 25-50% of cases, however, they continue to be overlooked, leading to a chronic Monteggia injury. Initially, the chronic Monteggia injury is only characterized by a moderate motion deficit, which is often masked by compensatory movements. Later, however, there is a progressive valgus deformity, neuropathy of the ulnar nerve and a progressive deformity of the radial head ("mushroom deformity") with ultimately painful radiocapitellar arthrosis. In the early stages, when the radial head is not yet deformed and there is no osteoarthritis in the humeroradial joint, these injuries can be treated with reconstruction procedures. This can be achieved either by an osteotomy of the proximal ulna with or without gradual lengthening. If there is already a severe deformity of the radial head and painful osteoarthritis, only rescue procedures such as functional radial head resection or radial head resection with or without hemi-interposition arthroplasty can be used to improve mobility and, above all, to eliminate pain. In this review article, we provide an overview of the current treatment options of chronic Monteggia injury in children and adolescents and present a structured treatment algorithm depending on the chronicity and dysplastic changes.

O166: Safety and Efficacy of Autologous Fat Grafting in the Treatment of Radiation-Induced Fibrosis and Contour Defects in Head and Neck Reconstruction

Abstract Background Multimodal treatment for head and neck cancer results in significant functional and cosmetic morbidity, often through contour deformity and radiation-induced skin fibrosis (RIF), affecting head and neck function and cosmesis. Autologous fat grafting is an emerging treatment for RIF. We conducted a retrospective cohort review of patient outcomes following autologous fat transfer for reconstruction of head and neck contour deformity and RIF. Methods A retrospective analysis was performed of patients treated at 2 UK centres between 2009-2022. Patient data collated included demographics, oncological treatment, reconstruction, operative details, and pre- and post-operative patient reported outcome measures (PROMs) including University of Washington Quality of Life Questionnaire (UW-QOL), Derriford Appearance Scale (DAS24) and Patient Outcomes of Surgery (POS). Patients were stratified by indication for AFG. Results A total of 45 patients were identified. 89% of patients (85% RIF, 92% contour deformity) reported cosmetic or functional improvement. Two patients (4%) reported no improvement, and three (7%) were lost to follow-up. Psychological health scores improved in patients following AFG for both RIF and contour deformity patients (DAS24, P< 0.0001). The UW-QOL scores revealed statistically significant improvements in multiple functional domains including appearance, activity, recreation, mood, and anxiety in both patients with RIF and contour deformities. Conclusion This study demonstrates that AFG is an effective technique for the correction of contour deformity and RIF in patients following treatment for head and neck cancer. Patients suffering from RIF demonstrated significant improvements in both functional and psychological domains.

Quality of life and clinical outcomes in severely involved cerebral palsy patients and spastic hips undergoing Castle surgery: a cross-sectional study.

As progressive hip dislocation causes pain in children with spastic cerebral palsy (CP) and spasticity needs surgical correction, we aimed to describe clinical and radiographic outcomes in CP patients with painful hip deformity treated with the Castle salvage procedure. We included all patients operated in the same hospital between 1989 and 2017 with painful spastic hips and femoral head deformity making joint reconstruction unfeasible. We collected clinical and functional data from medical records and evaluated radiographies to classify cases for femoral head shape and migration, type of deformity, spinal deformity, and heterotopic ossification. We investigated quality of life oneyear after surgery. We analyzed 41 patients (70 hips) with complete medical records. All had severe function compromise GMFCS V (Gross Motor Function Classification System) and heterotopic ossifications, all but one had scoliosis, and most had undergone other surgeries before Castle procedure. Patients were followed up for 77.1months (mean) after surgery. The mean initial migration index was 73%. Seven patients had complications, being three patients minor (two femur and one tibial fracture) and four majors (patients requiring surgical revision). Quality of life was considered improved by most of the carers (35 children; 85.3%) as level 4/5 according to CPCHILD instrument. No child was able to stand or walk, but moving in and out of bed, of vehicles, and to a chair, remaining seated, or visiting public places was "very easy." We considered most patients (37 patients-90%, 66 hips-94%) as having satisfactory outcomes because they had no or minor complications, absence of pain, free mobility of the lower limbs and were able to sit in a wheelchair.

Global trends in the research on Legg-Calve-Perthes disease in Web of Science.

Legg-Calve-Perthes disease (LCPD) is a form of idiopathic femoral head necrosis that can lead to permanent femoral head deformities and premature osteoarthritis in children under the age of 15. Its pathogenesis is utterly and remains to be clarified. Although many research publications on LCPD have emerged during the last few decades, few systematic bibliometric analyses of these articles have been reported. A bibliometric analysis was performed to investigate the development processes and hotspots, as well as the collaboration and influence among countries, institutions, authors, journals, and keywords of papers relevant to LCPD from the Web of Science Core Collection (WoSCC) during the period from 1 January 2000 to 30 June 2023. A total of 2,205 researchers from 916 institutions across 53 countries/regions have contributed to 673 papers published in 199 academic journals. The research on LCPD has shown significant fluctuations but a gradual increase in the number of articles published over the last two decades. The United States leads in the number of publications of LCPD, with the Texas Scottish Rite Hospital for Children being the most productive institution. English, as the most widely used language in the world, was undoubtedly the most popular language. Herring JA, who acted as both the corresponding and first author, has contributed to the most co-cited papers published. The most number of LCPD papers are published in the Journal of Pediatric Orthopaedics, whereas the Journal of Bone and Joint Surgery American Volume garnered the highest total citations, indicating the great importance of these two journals in the field of orthopedics. The most frequently used keywords in published articles were related to the symptoms, mechanisms, and prognosis, revealing the research focus of most scholars. Our research described the development trends and hotspots in the research field of LCPD and will help researchers make better decisions.

Deletion of ACTRT1 is associated with male infertility as sperm acrosomal ultrastructural defects and fertilization failure in human.

Could actin-related protein T1 (ACTRT1) deficiency be a potential pathogenic factor of human male infertility? A 110-kb microdeletion of the X chromosome, only including the ACTRT1 gene, was identified as responsible for infertility in two Chinese males with sperm showing acrosomal ultrastructural defects and fertilization failure. The actin-related proteins (e.g. ACTRT1, ACTRT2, ACTL7A, and ACTL9) interact with each other to form a multimeric complex in the subacrosomal region of spermatids, which is crucial for the acrosome-nucleus junction. Actrt1-knockout (KO) mice are severely subfertile owing to malformed sperm heads with detached acrosomes and partial fertilization failure. There are currently no reports on the association between ACTRT1 deletion and male infertility in humans. We recruited a cohort of 120 infertile males with sperm head deformations at a large tertiary hospital from August 2019 to August 2023. Genomic DNA extracted from the affected individuals underwent whole exome sequencing (WES), and in silico analyses were performed to identify genetic variants. Morphological analysis, functional assays, and ART were performed in 2022 and 2023. The ACTRT1 deficiency was identified by WES and confirmed by whole genome sequencing, PCR, and quantitative PCR. Genomic DNA of all family members was collected to define the hereditary mode. Papanicolaou staining and electronic microscopy were performed to reveal sperm morphological changes. Western blotting and immunostaining were performed to explore the pathological mechanism of ACTRT1 deficiency. ICSI combined with artificial oocyte activation (AOA) was applied for one proband. We identified a whole-gene deletion variant of ACTRT1 in two infertile males, which was inherited from their mothers, respectively. The probands exhibited sperm head deformations owing to acrosomal detachment, which is consistent with our previous observations on Actrt1-KO mice. Decreased expression and ectopic distribution of ACTL7A and phospholipase C zeta were observed in sperm samples from the probands. ICSI combined with AOA effectively solved the fertilization problem in Actrt1-KO mice and in one of the two probands. Additional cases are needed to further confirm the genetic contribution of ACTRT1 variants to male infertility. Our results reveal a gene-disease relation between the ACTRT1 deletion described here and human male infertility owing to acrosomal detachment and fertilization failure. This report also describes a good reproductive outcome of ART with ICSI-AOA for a proband. This work was supported by the Chongqing medical scientific research project (Joint project of Chongqing Health Commission and Science and Technology Bureau, 2023MSXM008 and 2023MSXM054). There are no competing interests to declare. N/A.

Diamond-like carbon coating reduces connection screw head stripping after multiple tightening.

The stability of implant-abutment joint is fundamental for the long-term success of implant rehabilitation. The screw loosening, fracture, and head deformation are among the most common mechanical complications. Several surface treatments of titanium screws have been proposed to improve their resistance and stability. Diamond-like carbon (DLC) coating of the materials is widely used to increase their wear resistance and durability. The present study aimed to evaluate the effect of carbon fiber coating on the screw head on screw removal torque and screw head stripping. One hundred titanium implant screws were used, 50 without coating (Group 1) and 50 with DLC coating of the screw head (Group 2). Each screw was tightened with a torque of 25Ncm and unscrewed ten times. The removal torque was measured with a digital cap torque tester for each loosening. Optical 3d measurement of the screw head surface was performed by a fully automatic machine before and after multiple tightening to investigate surface modifications. The reverse torque values decreased with repeated tightening and loosening cycles in both groups without significant differences (p>0.05). Optical measurements of surface dimensions revealed average changes of 0.0357mm in Group 1 and 0.02312mm in Group 2, which resulted to be statistically significant (p<0.001). The DLC coating of the retention screw head can prevent its distortion and wear, especially after multiple tightening.

Legg-Calvé-Perthes Disease: Diagnosis, Decision Making, and Outcome.

Legg-Calvé-Perthes disease (LCPD), or idiopathic avascular necrosis of the proximal capital femoral epiphysis in children, has a variable presentation and can result in significant femoral head deformity that can lead to long-term functional deficits. Plain radiographic imaging is crucial in diagnosing LCPD and guiding treatment. Although the etiology of LCPD remains unknown, the evolution of the disease has been well characterized to include the phases of ischemia, revascularization, and reossification. The mechanical weakening during these phases of healing place the femoral head at high risk of deformity. Treatment of LCPD, therefore, focuses on minimizing deformity through operative and nonoperative strategies to reduce the risk of premature osteoarthritis. Advanced imaging using perfusion MRI may refine surgical decision making in the future, and biological treatments to improve femoral head healing are on the horizon.

Stretch-Induced Injury Affects Cortical Neuronal Networks in a Time- and Severity-Dependent Manner.

Traumatic brain injury (TBI) is the leading cause of accident-related death and disability in the world and can lead to long-term neuropsychiatric symptoms, such as a decline in cognitive function and neurodegeneration. TBI includes primary and secondary injury, with head trauma and deformation of the brain caused by the physical force of the impact as primary injury, and cellular and molecular cascades that lead to cell death as secondary injury. Currently, there is no treatment for TBI-induced cell damage and neural circuit dysfunction in the brain, and thus, it is important to understand the underlying cellular mechanisms that lead to cell damage. In the current study, we use stretchable microelectrode arrays (sMEAs) to model the primary injury of TBI to study the electrophysiological effects of physically injuring cortical cells. We recorded electrophysiological activity before injury and then stretched the flexible membrane of the sMEAs to injure the cells to varying degrees. At 1, 24, and 72h post-stretch, we recorded activity to analyze differences in spike rate, Fano factor, burstlet rate, burstlet width, synchrony of firing, local network efficiency, and Q statistic. Our results demonstrate that mechanical injury changes the firing properties of cortical neuron networks in culture in a time- and severity-dependent manner. Our results suggest that changes to electrophysiological properties after stretch are dependent on the strength of synchronization between neurons prior to injury.

Efficacy of Cranial Orthosis for Plagiocephaly Based on 2D and 3D Evaluation.

Background With the advent of cranial orthoses as therapeutic medical devices for the treatment of severe positional head deformities in Japan, an increasing number of patients are being treated with them. However, assessing the effectiveness of a treatment is often difficult due to the use of different metrics. This study aimed to evaluate the effectiveness of cranial orthoses for deformational plagiocephaly using two- (2D) and three-dimensional (3D) evaluation metrics. Methods We conducted a retrospective study of infant patients with deformational plagiocephaly who underwent cranial orthosis treatment. We evaluated the severity of deformational plagiocephaly using cranial asymmetry (CA) and the cranial vault asymmetry index (CVAI) as 2D metrics, and anterior and posterior symmetry ratios as 3D metrics. The patients were divided into 24 subgroups based on the initial severity of each outcome and their age at the start of treatment. We analyzed the changes in outcomes and correlations within improvements across the age and severity categories. Results Overall, 1,038 infants were included in this study. The mean CA, CVAI, and anterior and posterior symmetry ratios improved significantly after cranial orthosis treatment. The improvement in each score was greater in patients with more severe initial deformities and in those who underwent treatment at a younger age. Conclusion Cranial orthosis treatment was effective in correcting deformational plagiocephaly in infants, as demonstrated by improvements in both 2D and 3D metrics. Patients with more severe initial deformities and those who underwent treatment at a younger age showed greater improvement.

Seismic behavior of highway embankment reinforced with remedial countermeasures on saturated loose sandy layer

A hybrid pile system is proposed to suppress excessive settlement and lateral spreading, which are regarded as main causes of highway embankment failure due to earthquakes. This system, combining two groups of vertical and inclined piles arranged on both sides of highway embankment slope, can be applied to existing highway embankments. In this research, a series of 1 g shaking table tests were performed together with modeling the performance of highway embankments incorporating three cases with different reinforcements subjected to two sinusoidal waves. Several aspects of acceleration time history, pile deformation, and embankment settlement under three configurations were revealed and discussed to confirm the effectiveness of the proposed countermeasures. The results indicate that (1) the hybrid pile system can still ensure sufficient functionality to maintain the highway embankment after two consecutive strong earthquakes; (2) this system can also enhance the integrity of loose sandy layer to reduce the settlement and lateral spreading of embankment; (3) the inclined piles effectively reduce pile head deformation by increasing the shear strength of the pile.

Antifungal activity of poly(lactic acid) nanofibers containing the essential oil from Corymbia citriodora Hook or the monoterpenes β-citronellol and citronellal against mycotoxigenic fungi.

Food contamination by mycotoxigenic fungi is one of the principal factors that cause food loss and economic losses in the food industry. The objective of this work was to incorporate the essential oil from Corymbia citriodora Hook and its constituents citronellal and β-citronellol into poly(lactic acid) nanofibers; to characterize the nanofibers by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy and differential scanning calorimetry; to evaluate the antifungal activity by the fumigation method; to evaluate the antimycotoxigenic activity against Aspergillus carbonarius, Aspergillus ochraceus, Aspergillus westerdijkiae, Aspergillus flavus, and Aspergillus parasiticus; and to evaluate the morphology of these microorganisms. All the nanofibers had a regular, smooth, and continuous morphology. FTIR analyses confirmed that the active ingredients were incorporated into the polymer matrix. All samples exhibited antifungal and ochratoxigenic inhibitory activities of up to 100% and 99%, respectively, with the best results observed for (PLA+30 wt% β-citronellol) nanofibers and (PLA+30 wt% citronellal) nanofibers. However, 100% inhibition of the production of aflatoxin B1 and B2 was not observed. The images obtained by SEM indicated that the nanofibers caused damage to the hyphae, caused a decrease in the production of spores, and caused deformation, rupture, and non-formation of the conid head, might be an alternative for the control of mycotoxigenic fungi.

Arthroscopic and Radiographic Features Distinguish Femoral Head Deformity from Idiopathic Cam, Slipped Capital Femoral Epiphysis, and Recurrent Cam After Slipped Epiphysis.

Hip impingement from slipped epiphysis and idiopathic cam is well known but not fully differentiated. Idiopathic cam can be a result of an undiagnosed slip. The mechanism of remodeling of slipped epiphysis deformity has also been controversial. The causes of recurrent femoral head deformity and new impingement beyond progression of the slip have not been studied. A consecutive series of hips treated by arthroscopic femoral neck osteoplasty for impingement from slipped epiphysis were compared with a series of hips treated for idiopathic cam impingement. Demographics and clinical, radiographic, and arthroscopic features were retrospectively retrieved. The same parameters were studied in another consecutive series of hips treated for slipped epiphysis and developed recurrent pain from impingement. The deformity was analyzed to understand the causes of recurrence in these hips. The medial most point where the femoral head sphericity ended was called the Alpha point and the tissue covering the bone at the Alpha point was identified. Children with idiopathic cam were older, had less pain and limp, and less clinical deformity compared to those with slipped epiphysis. The damage pattern was chondrolabral separation and acetabular cartilage debonding from the subchondral bone by an articular cartilage covered bump in idiopathic cam impingement, while it was labral crushing and labral and cartilage abrasion by metaphyseal bone in slip impingement. Recurrent cam deformities after initial slips were from epiphyseal extension similar to the idiopathic cam deformity in 7 out of 9 hips. Slipped epiphysis and idiopathic cam seem to be distinct entities at the time of presentation. They were different in all findings except for having pain with flexion and internal rotation in both groups. Remodeling of slip deformity seems to occur by wear of the metaphyseal prominence on the acetabulum. Recurrence or worsening of cam deformity in slips occurred by growth of the epiphysis on to the neck anteriorly which can appear as a decrease in the posterior slip. The relationship of the Alpha point to the physeal scar and the tissue covering the femoral head at the Alpha point help differentiate between epiphyseal and metaphyseal cam deformities. Level 3 retrospective comparative study.

FULLY AUTOMATIC SYSTEM TO DETECT AND SEGMENT THE PROXIMAL FEMUR IN PELVIC RADIOLOGICAL IMAGES FOR LEGG-CALVE-PERTHES DISEASE

The most important outcome predictor of Legg-Calvé-Perthes disease (LCPD) is the shape of the healed femoral head. However, the deformity of the femoral head is currently evaluated by non-reproducible, categorical, and qualitative classifications. In this regard, recent advances in computer vision might provide the opportunity to automatically detect and delineate the outlines of bone in radiographic images for calculating a continuous measure of femoral head deformity. This study aimed to construct a pipeline for accurately detecting and delineating the proximal femur in radiographs of LCPD patients employing existing algorithms. To detect the proximal femur, the pretrained stateof-the-art object detection model, YOLOv5, was trained on 1580 manually annotated radiographs, validated on 338 radiographs, and tested on 338 radiographs. Additionally, 200 radiographs of shoulders and chests were added to the dataset to make the model more robust to false positives and increase generalizability. The convolutional neural network architecture, U-Net, was then employed to segment the detected proximal femur. The network was trained on 80 manually annotated radiographs using real-time data augmentation to increase the number of training images and enhance the generalizability of the segmentation model. The network was validated on 60 radiographs and tested on 60 radiographs. The object detection model achieved a mean Average Precision (mAP) of 0.998 using an Intersection over Union (IoU) threshold of 0.5, and a mAP of 0.712 over IoU thresholds of 0.5 to 0.95 on the test set. The segmentation model achieved an accuracy score of 0.912, a Dice Coefficient of 0.937, and a binary IoU score of 0.854 on the test set. The proposed fully automatic proximal femur detection and segmentation system provides a promising method for accurately detecting and delineating the proximal femoral bone contour in radiographic images, which is necessary for further image analysis.

Reconstructing Smiles: Maxillofacial Prosthesis

Maxillofacial prosthesis are required for the reconstruction of head and neck deformities in patients with congenital anomalies or defects which are acquired like trauma, surgery, infection, burns, or cancer . These defects might need both extra oral and intraoral prosthetic rehabilitation. Re-evaluating the materials used in the field of maxillofacial prosthesis is beneficial because facial rehabilitation is necessary for the person to live a comfortable life. In addition to addressing the functional and aesthetic impairment, the prosthodontic therapy of these patients should focus on ensuring psychological wellbeing. From wax, metal, leather, rubber, etc., to the most recent biomedical material, like polymers, the materials have come a long way. While the new materials have shown some fantastic qualities, they have certain disadvantages. We are still looking for a material that possesses all the necessary qualities to rehabilitate maxillofacial deformities in the best way possible.

Fully automatic system to detect and segment the proximal femur in pelvic radiographic images for Legg-Calvé-Perthes disease.

This study aimed to develop a method using computer vision techniques to accurately detect and delineate the proximal femur in radiographs of Legg-Calvé-Perthes disease (LCPD) patients. Currently, evaluating femoral head deformity, a crucial predictor of LCPD outcomes, relies on unreliable categorical and qualitative classifications. To address this limitation, we employed the pretrained object detection model YOLOv5 to detect the proximal femur on over 2000 radiographs, including images of shoulders and chests, to enhance robustness and generalizability. Subsequently, we utilized the U-Net convolutional neural network architecture for image segmentation of the proximal femur in more than 800 manually annotated images of stage IV LCPD. The results demonstrate outstanding performance, with the object detection model achieving high accuracy (mean average precision of 0.99) and the segmentation model attaining an accuracy score of 91%, dice coefficient of 0.75, and binary IoU score of 0.85 on the held-out test set. The proposed fully automatic proximal femur detection and segmentation system offers a promising approach to accurately detect and delineate the proximal femoral bone contour in radiographic images, which is essential for further image analysis in LCPD patients.Clinical significance: This study highlights the potential of computer vision techniques for enhancing the reliability ofLegg-Calvé-Perthes diseasestaging and outcome prediction.

Impact of data synthesis strategies for the classification of craniosynostosis.

Photogrammetric surface scans provide a radiation-free option to assess and classify craniosynostosis. Due to the low prevalence of craniosynostosis and high patient restrictions, clinical data are rare. Synthetic data could support or even replace clinical data for the classification of craniosynostosis, but this has never been studied systematically. We tested the combinations of three different synthetic data sources: a statistical shape model (SSM), a generative adversarial network (GAN), and image-based principal component analysis for a convolutional neural network (CNN)-based classification of craniosynostosis. The CNN is trained only on synthetic data but is validated and tested on clinical data. The combination of an SSM and a GAN achieved an accuracy of 0.960 and an F1 score of 0.928 on the unseen test set. The difference to training on clinical data was smaller than 0.01. Including a second image modality improved classification performance for all data sources. Without a single clinical training sample, a CNN was able to classify head deformities with similar accuracy as if it was trained on clinical data. Using multiple data sources was key for a good classification based on synthetic data alone. Synthetic data might play an important future role in the assessment of craniosynostosis.

Numerical Simulation of Artificial Recharge Groundwater Effect on Overlying Soft Clay Compression Control

Soil deformation is prone to occur in the process of the foundation pit dewatering. A large number of metro existing tunnels are located in soft soil layers. The compression of soft soil poses a threat to metro existing tunnels. Previously, plenty of research on foundation pit dewatering is focused on the hydraulic head and deformation characteristics of the aquifer. However, the law of water releasing and compression deformation of overlying soft soil has not been taken seriously. In order to study the artificial recharge groundwater effect on overlying soft clay, a three-dimensional seepage–soil deformation coupling numerical model was established. The theoretical basis of the model is Darcy’s law and the principle of effective stress. A foundation pit located in Nanjing, China was selected as an example. The numerical model was used to simulate the hydraulic head and soil deformation caused by foundation pit dewatering and artificial recharge groundwater outside. The result shows that, due to the difference of hydraulic head between the aquifer and the aquitard reducing, it also has a good control effect on the deformation of the soft soil by recharging water into the aquifer. The location of recharge wells around the metro existing tunnel can control the soil deformation effectively, which could help to reduce the impact on the metro existing tunnel.