MiR-26b-5p/TET3 regulates the osteogenic differentiation of human bone mesenchymal stem cells and bone reconstruction in female rats with calvarial defects.

BACKGROUND: MicroRNAs (miRNAs) play critical roles in the osteogenic differentiation of human bone mesenchymal stem cells (hBMSCs), but the mechanism by which miRNAs indirectly modulate osteogenesis remains unclear. Here, we explored the mechanism by which miRNAs indirectly modulate gene expression through histone demethylases to promote bone regeneration. METHODS AND RESULTS: Bioinformatics analysis was performed on hBMSCs after 7 days of osteogenic induction. The differentially expressed miRNAs were screened, and potential target mRNAs were identified. To determine the bioactivity and stemness of hBMSCs and their potential for bone repair, we performed wound healing, Cell Counting Kit-8 (CCK-8), real-time reverse transcription quantitative polymerase chain reaction (RT‒qPCR), alkaline phosphatase activity, alizarin red S (ARS) staining and radiological and histological analyses on SD rats with calvarial bone defects. Additionally, a dual-luciferase reporter assay was utilized to investigate the interaction between miR-26b-5p and ten-eleven translocation 3 (TET3) in human embryonic kidney 293T cells. The in vitro and in vivo results suggested that miR-26b-5p effectively promoted the migration, proliferation and osteogenic differentiation of hBMSCs, as well as the bone reconstruction of calvarial defects in SD rats. Mechanistically, miR-26b-5p bound to the 3' untranslated region of TET3 mRNA to mediate gene silencing. CONCLUSIONS: MiR-26b-5p downregulated the expression of TET3 to increase the osteogenic differentiation of hBMSCs and bone repair in rat calvarial defects. MiR-26b-5p/TET3 crosstalk might be useful in large-scale critical bone defects.

Comparing the effects of Bone+B® xenograft and InterOss® xenograft bone material on rabbit calvaria bone defect regeneration.

BACKGROUND: The bone regeneration therapy is often used in patients with inadequate bone support for implants, particularly following tooth extractions. Xenografts derived from animal tissues are effective bone reconstructive options that resist resorption and pose a low risk of transmitting disease. Therefore, these implants may be a good option for enhancing and stabilizing maxillary sinuses. The purpose of this study was to compare two xenografts, Bone+B® and InterOss®, for the reconstruction of rabbit calvaria defects. METHODS AND MATERIALS: The study involved seven male New Zealand white rabbits. In the surgical procedure, 21 spots were created on both sides of the midline calvarium by creating three 8-millimeter defects. A control group was used, as well as two treatment groups utilizing Bone+B® Grafts and InterOss® Grafts. After 3 months, the rabbits were euthanized, followed by pathological evaluation. Analysis of these samples focused on bone formation, xenograft remaining material, and inflammation levels, using Adobe Photoshop CS 8.0 and SPSS version 24. RESULTS: With the application of Bone+B® graft, bone formation ranged from 32% to 45%, with a mean of 37.80% (±5.63), and the remaining material ranged from 28% to 37%, with a mean of 32.60% (±3.65). Using InterOss® grafts, bone formation was 61% to 75%, the mean was 65.83% (±4.75), and the remaining material was 9% to 18%, with a mean of 13.17% (±3.06). The bone formation in the control group ranged from 10% to 25%, with a mean of 17.17% (±6.11). InterOss® had lower inflammation levels than other groups, but the difference was not statistically significant (p > .05). CONCLUSION: InterOss® bone powder is the best option for maxillofacial surgery and bone reconstruction. This is due to more bone formation, less remaining material, and a lower inflammation level. Compared to the control group, Bone+B® improves healing and bone quality, thus making it an alternative to InterOss®.

Does cranial bone ossification differ in children with developmental dysplasia of the hip?

OBJECTIVES: This study aims to compare cranial bone ossification between patients with developmental dysplasia of the hip (DDH) and healthy individuals. PATIENTS AND METHODS: Between September 2021 and April 2022, a total of 60 healthy female individuals (median age: 24.5 months; range, 18 to 36 months) and 56 female DDH patients (median age: 23 months; range, 18 to 35 months) were included. Age, head circumference, weight, height, and patency of the anterior fontanel were measured in groups. Percentiles were classified as very low, low, normal, high and very high. All patients were female and those with abnormal thyroid function test, vitamin D, calcium, phosphate and alkaline phosphatase values were not included in the study. For those diagnosed with DDH, they were included in the group regardless of the type of treatment. RESULTS: No statistically significant difference was found between the groups in terms of age and weight (p>0.05). The very low and very high head circumferences were more frequent, and the normal head circumferences were less frequent in the DDH group (p<0.05). There was no significant difference between groups in terms of fontanel closure (p>0.05). In open fontanels, no significant difference was found in both groups in terms of age (p>0.05). CONCLUSION: Our study results showed no significant difference between the fontanel ossifications of children with and without DDH; however, we found that the ossification of the skull bones of children with DDH was different compared to healthy children.

Modified Mouse Model of Repetitive Mild Traumatic Brain Injury Incorporating Thinned-Skull Window and Fluid Percussion.

Mild traumatic brain injury is a clinically highly heterogeneous neurological disorder. Highly reproducible traumatic brain injury (TBI) animal models with well-defined pathologies are urgently needed for studying the mechanisms of neuropathology after mild TBI and testing therapeutics. Replicating the entire sequelae of TBI in animal models has proven to be a challenge. Therefore, the availability of multiple animal models of TBI is necessary to account for the diverse aspects and severities seen in TBI patients. CHI is one of the most common methods for fabricating rodent models of rmTBI. However, this method is susceptible to many factors, including the impact method used, the thickness and shape of the skull bone, animal apnea, and the type of head support and immobilization utilized. The aim of this protocol is to demonstrate a combination of the thinned-skull window and fluid percussion injury (FPI) methods to produce a precise mouse model of CHI-associated rmTBI. The primary objective of this protocol is to minimize factors that could impact the accuracy and consistency of CHI and FPI modeling, including skull bone thickness, shape, and head support. By utilizing a thinned-skull window method, potential inflammation due to craniotomy and FPI is minimized, resulting in an improved mouse model that replicates the clinical features observed in patients with mild TBI. Results from behavior and histological analysis using hematoxylin and eosin (HE) staining suggest that rmTBI can lead to a cumulative injury that produces changes in both behavior and gross morphology of the brain. Overall, the modified CHI-associated rmTBI presents a useful tool for researchers to explore the underlying mechanisms that contribute to focal and diffuse pathophysiological changes in rmTBI.

Fluorinated hydroxyapatite conditions a favorable osteo-immune microenvironment via triggering metabolic shift from glycolysis to oxidative phosphorylation.

BACKGROUND: Biological-derived hydroxyapatite is widely used as a bone substitute for addressing bone defects, but its limited osteoconductive properties necessitate further improvement. The osteo-immunomodulatory properties hold crucial promise in maintaining bone homeostasis, and precise modulation of macrophage polarization is essential in this process. Metabolism serves as a guiding force for immunity, and fluoride modification represents a promising strategy for modulating the osteoimmunological environment by regulating immunometabolism. In this context, we synthesized fluorinated porcine hydroxyapatite (FPHA), and has demonstrated its enhanced biological properties and osteogenic capacity. However, it remains unknown whether and how FPHA affects the immune microenvironment of the bone defects. METHODS: FPHA was synthesized and its composition and structural properties were confirmed. Macrophages were cultured with FPHA extract to investigate the effects of FPHA on their polarization and the related osteo-immune microenvironment. Furthermore, total RNA of these macrophages was extracted, and RNA-seq analysis was performed to explore the underlying mechanisms associated with the observed changes in macrophages. The metabolic states were evaluated with a Seahorse analyzer. Additionally, immunohistochemical staining was performed to evaluate the macrophages response after implantation of the novel bone substitutes in critical size calvarial defects in SD rats. RESULTS: The incorporation of fluoride ions in FPHA was validated. FPHA promoted macrophage proliferation and enhanced the expression of M2 markers while suppressing the expression of M1 markers. Additionally, FPHA inhibited the expression of inflammatory factors and upregulated the expression of osteogenic factors, thereby enhancing the osteogenic differentiation capacity of the rBMSCs. RNA-seq analysis suggested that the polarization-regulating function of FPHA may be related to changes in cellular metabolism. Further experiments confirmed that FPHA enhanced mitochondrial function and promoted the metabolic shift of macrophages from glycolysis to oxidative phosphorylation. Moreover, in vivo experiments validated the above results in the calvarial defect model in SD rats. CONCLUSION: In summary, our study reveals that FPHA induces a metabolic shift in macrophages from glycolysis to oxidative phosphorylation. This shift leads to an increased tendency toward M2 polarization in macrophages, consequently creating a favorable osteo-immune microenvironment. These findings provide valuable insights into the impact of incorporating an appropriate concentration of fluoride on immunometabolism and macrophage mitochondrial function, which have important implications for the development of fluoride-modified immunometabolism-based bone regenerative biomaterials and the clinical application of FPHA or other fluoride-containing materials.

New diagnostic criteria for metopic ridges and trigonocephaly: a 3D geometric approach.

BACKGROUND: Trigonocephaly occurs due to the premature fusion of the metopic suture, leading to a triangular forehead and hypotelorism. This condition often requires surgical correction for morphological and functional indications. Metopic ridges also originate from premature metopic closure but are only associated with mid-frontal bulging; their surgical correction is rarely required. Differential diagnosis between these two conditions can be challenging, especially in minor trigonocephaly. METHODS: Two hundred seven scans of patients with trigonocephaly (90), metopic rigdes (27), and controls (90) were collected. Geometric morphometrics were used to quantify skull and orbital morphology as well as the interfrontal angle and the cephalic index. An innovative method was developed to automatically compute the frontal curvature along the metopic suture. Different machine-learning algorithms were tested to assess the predictive power of morphological data in terms of classification. RESULTS: We showed that control patients, trigonocephaly and metopic rigdes have distinctive skull and orbital shapes. The 3D frontal curvature enabled a clear discrimination between groups (sensitivity and specificity > 92%). Furthermore, we reached an accuracy of 100% in group discrimination when combining 6 univariate measures. CONCLUSION: Two diagnostic tools were proposed and demonstrated to be successful in assisting differential diagnosis for patients with trigonocephaly or metopic ridges. Further clinical assessments are required to validate the practical clinical relevance of these tools.

Enhanced osteogenic and ROS-scavenging MXene nanosheets incorporated gelatin-based nanocomposite hydrogels for critical-sized calvarial defect repair.

The healing of critical-sized bone defects is a major challenge in the field of bone tissue engineering. Gelatin-related hydrogels have emerged as a potential solution due to their desirable properties. However, their limited osteogenic, mechanical, and reactive oxygen species (ROS)-scavenging capabilities have hindered their clinical application. To overcome this issue, we developed a biofunctional gelatin-Mxene nanocomposite hydrogel. Firstly, we prepared two-dimensional (2D) Ti3C2 MXene nanosheets using a layer delamination method. Secondly, these nanosheets were incorporated into a transglutaminase (TG) enzyme-containing gallic acid-imbedded gelatin (GGA) pre-gel solution to create an injectable GGA-MXene (GM) nanocomposite hydrogel. The GM hydrogels exhibited superior compressive strength (44-75.6 kPa) and modulus (24-44.5 kPa) compared to the GGA hydrogels. Additionally, the GM hydrogel demonstrated the ability to scavenge reactive oxygen species (OH- and DPPH radicals), protecting MC3T3-E1 cells from oxidative stress. GM hydrogels were non-toxic to MC3T3-E1 cells, increased alkaline phosphatase secretion, calcium nodule formation, and upregulated osteogenic gene expressions (ALP, OCN, and RUNX2). The GM400 hydrogel was implanted in critical-sized calvarial defects in rats. Remarkably, it exhibited significant potential for promoting new bone formation. These findings indicated that GM hydrogel could be a viable candidate for future clinical applications in the treatment of critical-sized bone defects.

Clinical and Anthropological Analyses of a Case From 19th Century South Africa With a Confluence of Uncommon Cranial Pathological Conditions.

This study combines clinical and anthropological analyses to investigate the complex cranial pathology of a South African individual from the 19th century. The cranium was examined macroscopically and radiographically. Conducting a standard differential diagnosis was challenging given the complexity and uncommon nature of the pathology and required drawing on relatively sparse paleopathological and clinical case reports. Multiple conditions were identified including biparietal thinning, basilar invagination, platybasia, and complicated chronic frontal sinusitis, where the intracranial extension of sinus infection may likely have contributed to the individual's death. The authors urge for awareness of these uncommon conditions, as their presence can easily be overlooked or confound skeletal assessments. This clinical study contributes to the authors' understanding of uncommon and poorly described paleopathological diseases and will help to better facilitate their diagnosis in future research. It represents one of the first studies describing such an unusual cooccurrence of uncommon pathologies in an archeological individual.

Evaluation of new bone formation in critical-sized rat calvarial defect using 3D printed polycaprolactone/tragacanth gum-bioactive glass composite scaffolds.

Critical-sized bone defects are a major challenge in reconstructive bone surgery and usually fail to be treated due to limited remaining bone quality and extensive healing time. The combination of 3D-printed scaffolds and bioactive materials is a promising approach for bone tissue regeneration. In this study, 3D-printed alkaline-treated polycaprolactone scaffolds (M-PCL) were fabricated and integrated with tragacanth gum- 45S5 bioactive glass (TG-BG) to treat critical-sized calvarial bone defects in female adult Wistar rats. After a healing period of four and eight weeks, the new bone of blank, M-PCL, and M-PCL/TG-BG groups were harvested and assessed. Micro-computed tomography, histological, biochemical, and biomechanical analyses, gene expression, and bone matrix formation were used to assess bone regeneration. The micro-computed tomography results showed that the M-PCL/TG-BG scaffolds not only induced bone tissue formation within the bone defect but also increased BMD and BV/TV compared to blank and M-PCL groups. According to the histological analysis, there was no evidence of bony union in the calvarial defect regions of blank groups, while in M-PCL/TG-BG groups bony integration and repair were observed. The M-PCL/TG-BG scaffolds promoted the Runx2 and collagen type I expression as compared with blank and M-PCL groups. Besides, the bone regeneration in M-PCL/TG-BG groups correlated with TG-BG incorporation. Moreover, the use of M-PCL/TG-BG scaffolds promoted the biomechanical properties in the bone remodeling process. These data demonstrated that the M-PCL/TG-BG scaffolds serve as a highly promising platform for the development of bone grafts, supporting bone regeneration with bone matrix formation, and osteogenic features. Our results exhibited that the 3D-printed M-PCL/TG-BG scaffolds are a promising strategy for successful bone regeneration.

Hydrogel loaded with thiolated chitosan modified taxifolin liposome promotes osteoblast proliferation and regulates Wnt signaling pathway to repair rat skull defects.

To alleviate skull defects and enhance the biological activity of taxifolin, this study utilized the thin-film dispersion method to prepare paclitaxel liposomes (TL). Thiolated chitosan (CSSH)-modified TL (CTL) was synthesized through charge interactions. Injectable hydrogels (BLG) were then prepared as hydrogel scaffolds loaded with TAX (TG), TL (TLG), and CTL (CTLG) using a Schiff base reaction involving oxidized dextran and carboxymethyl chitosan. The study investigated the bone reparative properties of CTLG through molecular docking, western blot techniques, and transcriptome analysis. The particle sizes of CTL were measured at 248.90 ± 14.03 nm, respectively, with zeta potentials of +36.68 ± 5.43 mV, respectively. CTLG showed excellent antioxidant capacity in vitro. It also has a good inhibitory effect on Escherichia coli and Staphylococcus aureus, with inhibition rates of 93.88 ± 1.59 % and 88.56 ± 2.83 % respectively. The results of 5-ethynyl-2 '-deoxyuridine staining, alkaline phosphatase staining and alizarin red staining showed that CTLG also had the potential to promote the proliferation and differentiation of mouse embryonic osteoblasts (MC3T3-E1). The study revealed that CTLG enhances the expression of osteogenic proteins by regulating the Wnt signaling pathway, shedding light on the potential application of TAX and bone regeneration mechanisms.

Senolytics ameliorate the failure of bone regeneration through the cell senescence-related inflammatory signalling pathway.

Stress-induced premature senescent (SIPS) cells induced by various stresses deteriorate cell functions. Dasatinib and quercetin senolytics (DQ) can alleviate several diseases by eliminating senescent cells. α-tricalcium phosphate (α-TCP) is a widely used therapeutic approach for bone restoration but induces bone formation for a comparatively long time. Furthermore, bone infection exacerbates the detrimental prognosis of bone formation during material implant surgery due to oral cavity bacteria and unintentional contamination. It is essential to mitigate the inhibitory effects on bone formation during surgical procedures. Little is known that DQ improves bone formation in Lipopolysaccharide (LPS)-contaminated implants and its intrinsic mechanisms in the study of maxillofacial bone defects. This study aims to investigate whether the administration of DQ ameliorates the impairments on bone repair inflammation and contamination by eliminating SIPS cells. α-TCP and LPS-contaminated α-TCP were implanted into Sprague-Dawley rat calvaria bone defects. Simultaneously, bone formation in the bone defects was investigated with or without the oral administration of DQ. Micro-computed tomography and hematoxylin-eosin staining showed that senolytics significantly enhanced bone formation at the defect site. Histology and immunofluorescence staining revealed that the levels of p21- and p16-positive senescent cells, inflammation, macrophages, reactive oxygen species, and tartrate-resistant acid phosphatase-positive cells declined after administering DQ. DQ could partially alleviate the production of senescent markers and senescence-associated secretory phenotypes in vitro. This study indicates that LPS-contaminated α-TCP-based biomaterials can induce cellular senescence and hamper bone regeneration. Senolytics have significant therapeutic potential in reducing the adverse osteogenic effects of biomaterial-related infections and improving bone formation capacity.

[Idiopathic hypertrophic pachymeningitis]. / Idiopaticheskii gipertroficheskii pakhimeningit.

The article presents a case of idiopathic hypertrophic pachymeningitis of a 61-year-old male patient with severe cephalgia and progressive neuropathy of the oculomotor nerves. The diagnosis was confirmed by MRI with gadolinium, which revealed thickening of the dura mater with accumulation of paramagnetic in the convexital parts of the frontal and temporal regions, as well as on the base of the skull and tentorium. During the use of pulse therapy with glucocorticosteroids (GCS) the symptoms regressed, but when the therapy was stopped, there was a relapse of ptosis and oculomotor abnormalities on the other side followed by a slower effect of GCS therapy. The article also presents a brief review of current knowledge about this pathology.

Resilient anatomy and local plasticity of naive and stress haematopoiesis.

The bone marrow adjusts blood cell production to meet physiological demands in response to insults. The spatial organization of normal and stress responses are unknown owing to the lack of methods to visualize most steps of blood production. Here we develop strategies to image multipotent haematopoiesis, erythropoiesis and lymphopoiesis in mice. We combine these with imaging of myelopoiesis1 to define the anatomy of normal and stress haematopoiesis. In the steady state, across the skeleton, single stem cells and multipotent progenitors distribute through the marrow enriched near megakaryocytes. Lineage-committed progenitors are recruited to blood vessels, where they contribute to lineage-specific microanatomical structures composed of progenitors and immature cells, which function as the production sites for each major blood lineage. This overall anatomy is resilient to insults, as it was maintained after haemorrhage, systemic bacterial infection and granulocyte colony-stimulating factor (G-CSF) treatment, and during ageing. Production sites enable haematopoietic plasticity as they differentially and selectively modulate their numbers and output in response to insults. We found that stress responses are variable across the skeleton: the tibia and the sternum respond in opposite ways to G-CSF, and the skull does not increase erythropoiesis after haemorrhage. Our studies enable in situ analyses of haematopoiesis, define the anatomy of normal and stress responses, identify discrete microanatomical production sites that confer plasticity to haematopoiesis, and uncover unprecedented heterogeneity of stress responses across the skeleton.

Development and application of hydroxyapatite-based scaffolds for bone tissue regeneration: A systematic literature review.

Hydroxyapatite [HA, Ca10(PO4)6(OH)2], with its robust biocompatibility and bioactivity, has found extensive utility in bone grafting, replacement therapies, and supplemental medical materials. HA is highly regarded for its osteoconductive properties because it boasts hydrophilicity, nontoxicity, non-allergenicity, and non-mutagenicity. Nevertheless, HA's intrinsic mechanical weakness has spurred efforts to enhance its properties. This enhancement is achieved through ion incorporation, with elements such as magnesium, zinc, lithium, strontium, boron, and others being integrated into the HA structure. In the domain of orthopedics, HA-based scaffolds have emerged as a solution for addressing prevalent issues like bone deformities and defects stemming from congenital anomalies, injuries, trauma, infections, or tumors. The fabrication of three-dimensional scaffolds (3D scaffolds) has enabled advancements in bone regeneration and replacement, with a focus on practical applications such as repairing calvarial, skull, and femoral defects. In vitro and in vivo assessments have substantiated the effectiveness of 3D scaffolds for bone defect repair, regeneration, and tissue engineering. Beyond bone-related applications, scaffolds demonstrate versatility in enhancing cartilage healing and serving as bioimplants. The wide array of scaffold applications underscores their ongoing potential for further development in the realm of medical science.

Magnetic resonance and computed tomographic imaging characteristics and potential molecular mechanisms of feline meningioma associated calvarial hyperostosis.

Meningiomas are the most common feline primary brain tumours, and calvarial hyperostosis (CH) is frequently documented in association with this neoplastic entity. The clinical significance of and mechanisms driving the formation of CH in cats with meningiomas are poorly understood, although tumour invasion into the skull and tumour production of cytokines and enzymes have been implicated as causes of CH in humans. This retrospective study investigated relationships between signalment, MRI or CT imaging features, histopathologic tumour characteristics, alkaline phosphatase (ALP) isoenzyme concentrations, tumour expression of matrix metalloproteinases (MMP)-2, MMP-9, and interleukin-6 (IL-6), and progression free survival times (PFS) following surgical treatment in 27 cats with meningiomas with (n = 15) or without (n = 12) evidence of CH. No significant differences in breed, age, sex, body weight, tumour grade, tumour volume, peritumoral edema burden, ALP isoenzyme concentrations, tumour Ki-67 labelling indices or MMP-2 or MMP-9 expression and activity, or PFS were noted between cats with or without CH. There was a trend towards higher serum (p = .06) and intratumoral (p = .07) concentrations of IL-6 in cats with CH, but these comparisons were not statistically significant. Histologic evidence of tumour invasion into bone was observed in 5/12 (42%) with CH and in no (0/6) cats without CH, although this was not statistically significant (p = .07). Tumour invasion into bone and tumour production of IL-6 may contribute to the formation of meningioma associated CH in cats, although larger studies are required to further substantiate these findings and determine their clinical relevance.

[Convexity hyperostotic meningioma en plaque: a systematic review]. / Ploskostnye giperostoticheskie meningiomy svoda cherepa. Sistematicheskii obzor literatury.

BACKGROUND: Planar hyperostotic meningiomas account for 2-9% of intracranial meningiomas. They are characterized by planar node following the contours of the inner surface of the skull. Hyperostosis is present in most cases. Timely diagnosis of skull base tumors is usually simple due to early involvement of the cranial nerves. However, convexity meningiomas en plaque usually reach large dimensions that complicates surgery and radiotherapy. OBJECTIVE: To analyze the current state of diagnosis, molecular biology and surgical treatment of hyperostotic meningiomas en plaque. MATERIAL AND METHODS: A systematic review was performed in accordance with the PRISMA guidelines. Searching for literature data included the following keywords: «planar meningioma¼, «hyperostotic meningioma¼, «meningioma en plaque¼, «infiltrative meningioma¼. We reviewed the PubMed and Google Scholar databases until May 2023 and enrolled only full-text Russian-, English- or French-language reports. RESULTS AND DISCUSSION: Among primary 332 reports, 35 references met the inclusion criteria. We found less severity or absence of focal neurological symptoms, comparable incidence of intracranial hypertension and no histological differences between planar and nodular meningiomas. Analysis of molecular biological features of planar meningiomas, including cell cultures, is feasible. There is no consensus regarding surgical treatment and radiotherapy. Most publications are case reports. CONCLUSION: The results of treatment of planar hyperostotic meningiomas, especially large and giant ones, are unsatisfactory. There is no a generally accepted algorithm for treating patients in the literature. This problem requires further research.

Intraosseous hemangioma with aneurysmal bone cyst-like changes of the hyoid bone: Case report and literature review.

RATIONALE: Intraosseous hemangioma is a rare benign vascular tumor of the bone that can affect any body part; however, the most common site is the vertebra, followed by calvarial bones. PATIENT CONCERNS: We present a case of intraosseous hemangioma in a 23-year-old male who presented a feeling of fullness in the throat for 3 months. The hyoid bone level had a hard mass of about 5 cm. Fine needle aspiration showed 5 mL dark bloody aspirates. Magnetic resonance image showed a 5.3 cm mixed signal intensity lesion in the hyoid body. DIAGNOSIS: Histopathologic examination showed intraosseous hemangioma with aneurysmal bone cyst (ABC)-like changes in the hyoid bone. INTERVENTIONS: The mass was completely removed without significant problems. OUTCOMES: Complete mass excision and symptomatic improvements were achieved, and no subsequent relapses were observed. LESSONS: The authors experienced a case of intraosseous hemangioma with ABC-like changes. There has been no case report of intraosseous hemangioma in the hyoid bone. This case showed a spectral pattern of the ABC-like changes developing from the underlying bone tumor as a secondary change. ABC-like changes in bone tumors can mislead the diagnosis. Careful examination of the tumor is essential for the correct diagnosis of ABC or ABC-like changes.

Reassessing trauma in a Late Neolithic cranium from Megalitho da Capella (Figueira da Foz, Portugal).

The Megalitho da Capella (Figueira da Foz, Coimbra, Portugal) is one of at least 21 dolmens in a megalithic complex explored by António dos Santos Rocha between 1880 and 1909. Among the human remains from Megalitho da Capella is an incomplete and fragmented cranium. Santos Rocha interpreted a groove on the parietal bone as an incision of traumatic origin with signs of remodeling that was suggestive of prolonged survival after an intentional intervention. This study provides a new examination of the groove using microcomputed tomographic (microCT) imaging, microscopy, and macroscopic observations of the groove in addition to the direct dating the skeletal remains. Results indicate that the human remains are dated to the Late Neolithic and that the "incision" is a normal anatomical variant corresponding to impressions from vascular tissue and temporal projections of the squamosal. We conclude that studies of bone surface modifications should consider normal anatomical variants (e.g., sulci, grooves, and furrows) when reporting results. Paleoimaging, microscopy, and comparative observations can assist in the identification bone modifications versus anatomical variants.

Langerhans cell histiocytosis of the skull in 23 children.

OBJECTIVE: To explore the clinical features, diagnosis, treatment and prognosis of Langerhans cell histiocytosis (LCH) of the skull in children. METHODS: This study retrospectively summarized the clinical manifestations, treatment methods and follow-up status of children with skull LCH who were admitted to the Department of Neurosurgery of Shanghai Children's Hospital from January 2014 to June 2021. RESULTS: A total of 23 patients confirmed by histology as LCH received hospitalization treatment, including 14 males and 9 females, aged (5.76 ± 3.86) years old. The clinical manifestations were mostly incidentally discovered head masses that gradually enlarged (19 cases, 82.61%). Only 2 cases are affected by multiple systems, while the rest are affected by single systems. 9 patients were involved in multiple skull lesions, and 14 patients had local skull lesions. All patients underwent surgical intervention, with 17 patients undergoing total resection and 6 patients undergoing biopsy. 21 patients received chemotherapy after surgery. The median follow-up was 2.46 years (range 0.33-6.83 years). 21 patients had their symptoms and signs under control or even resolved, and 2 patients experienced recurrence during follow-up. The overall control rate reached 91.30%. CONCLUSION: Personalized treatment plans according to different clinical types. Regular outpatient follow-up is crucial to monitor disease recurrence and late effects.

A novel micro-CT analysis for evaluating the regenerative potential of bone augmentation xenografts in rabbit calvarias.

Guided Bone Regeneration is a common procedure, yet, as new grafting materials are being introduced into the market, a reliable evaluation method is required. Critical size defect in animal models provides an accurate simulation, followed by histological sections to evaluate the new bone formation. However, histology is destructive, two-dimensional and technique-sensitive. In this study we developed a novel volumetric Micro-CT analysis to quantify new bone formation characteristics. Eight adult female New Zealand white rabbits were subjected to calvarial critical-size defects. Four 8 mm in diameter circular defects were preformed in each animal, to allow random allocation of four treatment modalities. All calvarias were scanned using Micro-CT. Each defect was segmented into four equal parts: pristine bone, outer, middle, and inner. Amira software (v. 6.3, www.fei.com ) was used to calculate the new bone volume in each region and compare it to that of the pristine bone. All grafting materials demonstrated that new bone formation decreased as it moved inward. Only the inner region differed across grafting materials (p = 0.001). The new Micro-CT analysis allowed us to divide each defect into 3D regions providing better understanding of the bone formation process. Amongst the various advantages of the Micro-CT, it enables us to quantify the graft materials and the newly formed bone independently, and to describe the defect morphology in 3D (bi- vs. uni-cortical defects). Providing an insight into the inner region of the defect can better predict the regenerative potential of the bone augmentation graft material. Therefore, the suggested Micro-CT analysis is beneficial for further developing of clinical approaches.