Immature Bone Research Articles

Shilajit potentiates the effect of chemotherapeutic drugs and mitigates metastasis induced liver and kidney damages in osteosarcoma rats

Osteosarcoma is a primary malignant cancer of the bone identified by the direct formation of osteoid tissue or immature bone by cancer cells. The liver and kidneys represent two major secondary organs to which osteosarcoma metastasizes. In this study, we assessed Shilajit, a phytomineral diffusion traditionally used in Ayurvedic medicine, for its possible protective effects against metastasis induced liver and kidney damages in an osteosarcoma rat model. Osteosarcoma rats displayed typical dysregulation of serum levels of hepatic and renal functional markers (p < 0.05) including aspartate aminotransferase (AST)* and alanine aminotransferase (ALT), alkaline phosphatase (ALP), total proteins, albumin, bilirubin, creatinine, urea, and uric acid. Changes in functional markers were also positively correlated with marked histopathological alterations in liver and kidney tissues. Whereas Shilajit's treatment of osteosarcoma rates in combination with CMF (cyclophosphamide, methotrexate, and 5-fluorouracil) chemotherapy drug cocktail significantly (p < 0.05) reversed the studied functional markers to their near-normal levels. Co-treatment of shilajit and drug cocktails also markedly alleviated histopathological changes in liver and kidney tissues. Correlation co-efficient analysis of hepatic and renal functional markers revealed a significant inter-association among these markers. Collectively, present data indicate that shilajit may potentiate the effects of chemotherapy drugs and mitigate the metastasis-induced liver and kidney damage in osteosarcoma. Thus, the findings of this study substantiate the beneficial health effects of shilajit and promote its regular consumption.

Osseous Microanatomy and Histochemical Characterization in Species, Gender Determination and Age Estimation

Background: Bone is a tissue of particular interest, because the hard tissue of the skeleton is normally well preserved and details of microscopic structure can be seen in specimens many centuries old. The microscopic structure of bone can be utilized for identification of unknown bone samples in forensic odontology. Physical anthropologists may encounter complete or fragmentary specimens of bone in which standard anthropometric methods provide inconclusive or questionable information. If the histological structure of such material could reveal, with reasonable accuracy, details of species, age, and gender, it would be a useful and valuable laboratory tool. Materials and Methods: A cross-sectional analysis of formalin fixed paraffin embedded sections from biopsied lesions (5 cases each of goat bone, 5 cases of chicken bone specimen, 5 cases of human male bone specimen, 5 cases of human female bone specimen) was done. The variation of the trabeculae by measuring the average width of trabeculae, the average marrow space, and the ratio of the above two through morphometric analysis was assessed. The observational percentage variation amongst the species by number of osteons, osteocytes shape i.e., -spindle, elliptical and round, presence of inflammation was noted. The stroma and hard tissue for Collagen characterization (Special stains)Type, orientation and maturity using Picrosirus stain, Sub intimal fibrosis surrounding the bone using Van Gieson, Percentage of mature and immature bone pattern using Azan stain was analyzed. Result: Chicken bone shows absence of osteons in comparison to human bone with increased number of osteocytes. Goat bone shows plexiform pattern with scattered haversian canals more comparable to human bone architecture. Average human Haversian canal diameter was greater than non-human mammalian species. Azan staining helped in differentiation of mature from immature bone. Picrosirus staining helped in establishing collagen type, orientation and thickness. Sub intimal fibrosis surrounding the bone was checked using Van Gieson staining. Discussion: The complexities of bone tissue and its growth processes are such that misinterpretations of a critical nature can be made if the observer is not well informed on the multitude of basic details dealing with Osteogenesis, remodelling, and comparative histology. Conclusion: Bone histomorphological assessment is an effective method for species identification, gender determination and age estimation by fragmentary osseous remains.

Reconstruction of critical size segmental femoral diaphyseal defects of New Zealand rabbits by using combined titanium mesh cage and induced membrane technique.

Long bone defects due to fractures resulting from high-energy trauma, infections and tumor resections are problems that orthopedic surgeons commonly face. We investigated the effects of a titanium mesh cage on bone healing with an induced membrane technique. Three groups, each composed of eight rabbits, were formed. Extraarticular diaphyseal bone defects were created. Femora of the first group were fixed with an empty titanium mesh cage and two K-wires. After formation of the defect, polymethylmethacrylate was inserted and fixed with a K-wire in the second group. At the third week, the cement was removed, a sterilized cancellous graft-filled titanium mesh cage was placed into the defect, and the membrane that was previously formed over the cement was placed on the cage and repaired. In the third group, sterilized cancellous grafts were filled into the titanium mesh cage, and the titanium mesh cage was fitted into the bone defect area. At the end of the third month, all subjects were killed. Radiological data revealed that the healing of the bone in the second and third groups was significantly better than that in the first group. There was no difference between the second and third groups. A histological evaluation of the healing status, such as fibrous tissue, cartilage tissue and mature or immature bone formation, was performed. Histological healing in the second and third groups was also significantly better than that in the first group. We concluded that the combination of membrane-induced bone healing and graft-filled titanium mesh cages expedites osteogenesis in extraarticular bone defects.

Outcomes of Semiknee Replacement in Skeletally Immature Bone Sarcoma Patients.

A semiknee mega endoprosthesis (SKMEP) was used to replace the resected distal femur or proximal tibia in skeletally immature bone sarcoma patients. This study investigated the surgical technique, endoprosthesis survival rate, functional outcome, complications, and approaches to resolve limb-length discrepancy (LLD) following this procedure. In total, 15 girls and 16 boys with a mean age of 9.1 years (range, 4-12) and 8.9 years (range, 5-13), respectively, were included in this study. The mean length of the resected distal femur (15 cases) and proximal tibia (16) was 145.0 and 122.8 mm, respectively. Altogether, 19 custom-made SKMEPs and 12 modular units were used to reconstruct the bone and joint defects. The average follow-up was 82.8 months (range, 4-225 months). Five patients died of disease. Seven SKMEPs were revised to total knee endoprosthesis after a mean of 40.3 months. Nineteen patients retained the original SKMEP, and the mean LLD was 4.3 cm (range, 0-10 cm). One case each of Henderson type 1B, type 2A, type 2B, and type 5B failures was observed. Knee subluxation occurred in two cases. Although a slight laxity of the knee was identified on physical examination, the average Musculoskeletal Tumor Society 93(MSTS93) functional score was 84.5% (range, 57-97%). The estimated implant survival was 70.5% at 5 years. This was the largest retrospective study reporting the application of SKMEP in bone sarcoma patients. For selected skeletally immature bone sarcoma patients, SKMEP is an option with satisfactory functional outcomes and survival rates. However, heightening pads or shoes to compensate the LLD were indispensable before subsequent LLD was adjusted by further operation(s).

NiTi laser textured implants with improved in vivo osseointegration: An experimental study in rats

Laser surface texturing is a versatile approach for manufacturing implants with suitable surfaces for osseointegration. This work explores the use of laser to fabricate NiTi textured implants, testing two different groove-based designs. Their performance was evaluated in vivo through implantation in Sprague Dawley rats’ femur, being then analyzed after 4 and 12 weeks of implantation. Push-out experiments and histological characterization allowed to assess bone-implant bond and osseointegration and to compare the laser textured solutions with non-textured NiTi. Histology showed that, at 4 weeks of implantation, mainly immature woven bone was present whilst at 12 weeks a more mature bone had developed. Considering the largest implantation time (12 weeks), results showed extraction forces considerably higher for textured implants (G2 and G3). Moreover, when comparing G2 and G3, it was found that G2 (having the highest textured surface area) displayed the maximum extraction force among all groups, with an increase of 212% when compared to non-textured implants (G1). These results prove that the design and manufacturing technology are effective to promote an improved bone-implant bond, aiming the development of orthopedic implants.

Histological and histomorphometric evaluation of alveolar ridge preservation using an allograft and nonresorbable membrane with and without primary closure: A pilot randomized controlled clinical trial.

The aim of this article is to assess the formation of new vital bone (VB) using histomorphometric analysis in alveolar ridge preservation (ARP), with and without primary closure. Eight patients needed bilateral tooth extraction and planned for ARP. All patients had a nonresorbable membrane with freeze-dried bone allograft after the extractions. Biopsies were obtained 6 months after ARP and were evaluated using histomorphometric analysis. The study included 6 males and 2 females, with an average age of 54.2 years (standard deviation, 9.7). The teeth requiring extraction included a bilateral canine (1 case), premolars (5 cases), and molars (2 cases). Histomorphometric values of new VB, residual bone (RB) substitute particles, and marrow tissue formation were 71.1 %, 16.2%, and 9.69% for closed flap and 50.9%, 15.3%, and 8.19 for open flap. P values were 0.066, 0.878, and 0.326, respectively. The present findings indicate that leaving the flap without primary closure did not have any effect on new VB, RB particles, and immature bone marrow compared with closed flap. However, the results favored the closed-flap technique.

The most economical arthroscopic suture fixation for tibial intercondylar eminence avulsion fracture without any implant

BackgroundAvulsion fracture of the tibial intercondylar eminence is a rare injury, which mainly occurs in adolescents aged 8–14 years and in those with immature bones. The current commonly used surgery may result in severe surgical trauma, affecting knee joint function and accompanied by serious complications. In this study, we described an all-inside and all-epiphyseal arthroscopic suture fixation technique for a patient to treat tibial intercondylar eminence fracture.MethodsETHIBOND EXCEL-coated braided polyester sutures were used for fixation. Three ETHIBOND sutures were passed through the ACL at 2, 6 and 10 o’clock of the footprint of the ACL and made a cinch-knot loop separately. Under the guidance of ACL tibial locator, three corresponding tibial tunnels were drilled with K-wires at 2, 6 and 10 o’clock of the fracture bed, and the two ends of the suture were pulled out through the tunnel with double-folded steel wire heads. After reduction of the tibial eminence, three sutures were tightened and tied to the medial aspect of the tibial tubercle.ResultsAfter all the surgical treatments surgically performed by this method and following a standard postoperative protocol, our patient's ROM, stability, and functional structural scores all improved significantly.ConclusionThis three-point suture technique provides a suitable reduction and stable fixation and is suitable for patients with all types of avulsion fractures of the tibial intercondylar eminence.

Obesity Pillars roundtable: Metabolic and bariatric surgery in children and adolescents

BackgroundObesity is a chronic disease which frequently begins in childhood and requires a life-long multidisciplinary approach. Metabolic-bariatric surgery (MBS) is a key component of the treatment of severe obesity in children, adolescents and adults. Children and adolescents who have class II obesity and a complication of obesity or have class III obesity should be considered for MBS, regardless of age, race, sex, or gender. Children and adolescents with cognitive disabilities, a history of mental illness, a treated eating disorder, immature bone growth, or low Tanner Stage should not be denied treatment. Early intervention can reduce the risk of persistent obesity, end organ damage, and sequelae from long-standing complications of obesity. MethodsThis roundtable discussion includes three pediatric obesity specialists with experience in the medical and surgical management of children and adolescents with obesity. Included are citations regarding metabolic-bariatric surgery in children and adolescents. ResultsMBS in pediatric patients is increasingly recognized as an essential part of managing the disease of obesity in combination with medication, nutrition, behavioral training, and physical activity. Vertical sleeve gastrectomy or Roux-en-Y gastric bypass in patients meeting criteria for severe obesity should be considered, especially when children have complications such as poor quality of life, orthopedic disease, idiopathic intracranial hypertension, type 2 diabetes mellitus, obstructive sleep apnea, or cardiovascular risk. Children and adolescents with autism, developmental delay, or syndromic obesity should be considered for MBS on a case-by-case basis. Early intervention may result in improved long-term outcomes, and referral for MBS should not be conditional based on stage of pubertal development (Tanner Staging), bone age, or prior weight loss attempts. ConclusionsChildren and adolescents who suffer from severe obesity need the entire spectrum of treatment modalities available to achieve a healthy weight and control obesity-related complications. This treatment spectrum should include MBS. These children and adolescents should be cared for by a pediatric weight management team prepared to care for them until they transition to adult care.

Osseous metaplasia in multiple broad ligament leiomyomas: An extreme rarity

Osseous metaplasia in a leiomyoma is an uncommon clinical entity with the presence of mature and immature bone in a leiomyoma. Infection, necrosis, hyaline degeneration, calcification and myxoid degeneration are the most common secondary degenerative changes seen in cases of leiomyoma. Calcified and ossified leiomyomas are uncommon and is rarely reported in literature. We report one such case in a 45 year old perimenopausal female who presented clinically with abnormal uterine bleeding. Multiple nodules were seen in bilateral broad ligaments, which on histopathology revealed features of osseous metaplasia in hyalinized degenerated leiomyomas, an extremely rare clinical entity.

A collagen membrane for periosteal expansion osteogenesis using a timed-release system in rabbit calvaria

BackgroundThe purpose of this study was to evaluate the effects of resorbable membranes, combined with a shape memory alloy (SMA) mesh device, on bone formation using a timed-release system for periosteal expansion osteogenesis (TIME-PEO).Materials and methodsTwelve Japanese white rabbits were used in this study. An SMA device was inserted under the forehead periosteum, pushed and bent for attachment to the bone surface, and then fixed using resorbable thread. The rabbits were divided into four groups: C1 (5 weeks postoperatively without membrane), C2 (8 weeks postoperatively without membrane), E1 (5 weeks postoperatively with membrane), and E2 (8 weeks postoperatively with membrane). The rabbits were killed 5 or 8 weeks after the operation and the newly formed bone was assessed histologically and radiographically.ResultsSMA devices, concealed under soft tissue until the time of euthanasia, did not cause active inflammation. The mean activation height, from the original bone surface to the midpoint of the mesh, was 3.1 ± 0.6 mm. Newly formed bone was observed, and most of the subperiosteal space underneath the device was occupied by fibrous tissue. Immature bone was present at the outer surface of the original skull bone in all groups. On histomorphometric analysis, there was no significant difference in the volume of the new bone between C1 and E1 (p = 0.885), and C2 and E2 (p = 0.545).ConclusionsPEO using an SMA mesh device, which is based on guided bone regeneration (in atrophic alveolar bone), shows promise as an alternative for bone augmentation, irrespective of whether a resorbable membrane is used.

Implant Osseointegration in Grafted Autogenous Bone Blocks Fixed with Screws and Cyanoacrylate-Based Adhesive: Histomorphometric and Micro-CT Analyses.

To evaluate implant osseointegration in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Also, grafted bone fixed either with an adhesive or screw was evaluated. Two surgical defects in the parietal region of rabbits (n = 12) were performed in each animal. Autogenous bone blocks obtained were fixed anteriorly with a screw or cyanoacrylate-based adhesive. After 30 and 45 days of grafting procedures, implants were placed in bone blocks. Histomorphometric and microcomputed tomography (micro-CT) analyses of the implant area were performed at 30 days after implant surgery in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric analyses of bone-grafted areas were performed at 60 and 75 days in the screw (n = 6) and adhesive (n = 6) groups. Histomorphometric evaluations were carried out in implant and grafted bone areas. The micro-CT parameters evaluated were bone-to-implant contact, bone area fraction occupancy, bone volume fraction, trabecular thickness, trabecular separation, and trabecular number. No differences were observed in the micro-CT parameters for the screw and adhesive groups in all experimental periods. However, an increased quantity of immature bone volume was observed on the adhesive group in the grafted area after 75 days. The grafted area in the screw group (75 days) presented a decrease in the volume density of the immature bone compared with the screw group (60 days). There were no differences in both groups and experimental periods in soft tissue in the grafted area. No differences were observed in the osseointegration of implants placed in grafted autogenous bone blocks fixed with cyanoacrylate-based adhesive and screws. Therefore, osseointegration in autogenous bone fixed with cyanoacrylate-based adhesive is viable.

Long-Term Results of Fibrous Dysplasia of the Paranasal Sinuses.

Fibrous dysplasia (FD) is a benign, idiopathic skeletal disorder, in which the normal bone and marrow are replaced by fibrous tissue and immature woven bone. The authors aim to analyze the long-term results of patients diagnosed with FD of the paranasal sinuses via imaging or surgical biopsy. The authors retrospectively enrolled 21 patients with FD of the paranasal sinuses from 2006 to 2021. The mean age at the time of diagnosis of FD of the paranasal sinuses was very high at 45.9 years. The most common site ofoccurrence was the sphenoid sinus (71.4%). During the mean follow-up period of 52.8 months, there was no significant change in the size of FD of the paranasal sinuses, and there was no worsening of symptoms or complications. Endoscopic sinus surgery was performed in 16 patients (76.2%), of which 13 underwent only biopsy and 3 underwent partial resection. The most common site of FD of the paranasal sinuses was the sphenoid sinus, and the age at diagnosis was higher thanthat of patients with FD at other sites. Observation with serial radiologic examinations is recommended for asymptomatic FD of the para-nasal sinuses.

Enhancing the bioactivity of melt electrowritten PLLA scaffold by convenient, green, and effective hydrophilic surface modification

As an emerging additive manufacturing (AM) technique, melt electrospinning writing (MEW) is used to fabricate three-dimensional (3D) submicron filament-based scaffolds with adjustable pore size and customized structure for bone regeneration. Poly(L-lactic acid) (PLLA) scaffold with excellent biodegradability and biocompatibility is first successfully manufactured using our self-assembled MEW device. However, the ultralow cell affinity and poor bioactivity severely hamper their practical applications in bone tissue engineering. These issues are caused by the severe inherent biologically inert, hydrophobicity as well as the smooth surface of the MEW PLLA filaments. In this study, a green and robust alkaline method is applied to modify the scaffold surface and to improve the bioactivity of the MEW PLLA scaffold. Without deterioration in mechanical property but robust surface hydrophilicity, the optimal MEW PLLA scaffold shows promoted surface roughness, enhanced filament tensile modulus (~ 2 folds of the as-prepared sample), and boosted crystallizability (ultrahigh WAXD intensity). Moreover, after being cultured with KUSA-A1 cells, the 0.5 M NaOH, 2 h treated MEW PLLA scaffold exhibits higher osteoinductive ability and increased immature bone tissue amounts (3 times of controlled scaffold). Thus, the flexible surface functionalization by the specific alkaline treatment was found to be an effective method for the preparation of bioactivated MEW PLLA scaffolds with promoted bone regeneration.

Differential expression profiles and function prediction of tRNA-derived fragments in fibrous dysplasia

ObjectiveFibrous dysplasia (FD) is a bone disease featuring that normal bone matrix is replaced by fibrous tissue and immature bone tissue. Transfer RNA-derived RNA fragments (tRFs) and tRNA halves (tiRNAs) are types of small non-coding RNA that produced by specific shearing of mature tRNA. Here, we conducted a comparative analysis of the expression of tRFs/tiRNAs in BMSCs and FD BMSCs. DesignsThe differential expression of tRFs/tiRNAs was detected by high-throughput sequencing technique, and validated by qRT-PCR. Bioinformatics analyses including prediction of target genes, gene ontology (GO) enrichment and KEGG pathway analysis and protein-protein interaction (PPI) network analysis were performed. ResultsThe results detected 1 significantly upregulated tDR (tRNA-derived small RNA) and 3 downregulated tDRs in FD BMSCs. Predictions of target genes, GO and KEGG pathway analysis indicated that these tRFs were mainly involved in regulation of immune response, osteoclast differentiation, calcium ion transport, apoptotic signaling pathway, cell proliferation and endocrine system development. The PPI network analysis showed that PPP2R5A, ADAMTS1, PPARA, and POLR2C were the most frequently interacted proteins in target genes. ConclusionsOur findings provided a comprehensive analysis of the expression of tRFs/tiRNAs in FD BMSCs and BMSCs, and they could serve as potential therapeutic targets.

Specific Characteristic of Hyperplastic Callus in a Larger Cohort of Osteogenesis Imperfecta Type V.

Hyperplastic callus (HPC) is the most conspicuous features of osteogenesis imperfecta (OI) type V, of which accurate diagnosis and treatment are facing challenges. We investigate the clinical features, and impact factors of HPC in OI type V patients. In this retrospective single-center study, a total of 21 patients with type V OI confirmed by IFITM5 mutation were included. Radiological characteristics of bone were evaluated by X-rays, dual-energy X-ray absorptiometry, and computed tomography scan. Bone biopsy specimens were performed and stained by routine hematoxylin-eosin. The effects of bisphosphonates on HPC were investigated. Eleven patients (52.3%) had HPCs at 19 skeletal sites, 11 of which affected the femur. Three patients developed four (21.1%) HPCs after fractures, and 15 (78.9%) HPCs occurred in absence of bone fracture. The progress of HPCs was variable, of which most HPCs enlarged in the initial phase and remained stable, and only one HPC dwindled in size. One patient had a rapidly growing mass on the right humerus, and biopsy showed irregular trabeculae of woven bone and immature bone and cartilage in the loose and edematous collagenous network without signs of tumor. Bisphosphonates treatment had no significant effects on HPC of OI patients. HPC is the specific characteristic of OI type V patients, and its location, shape, size, and progression are variable, and the femur is the most frequently involved site. It is very important to make a diagnosis of HPC through detecting IFITM5 mutation and completing pathological diagnosis if necessary. The treatment of HPC is worth further exploration.

Osseointegration Assessment of Multi‐Material Ti6Al4V‐β TCP Implants: An Experimental Study in Rats

AbstractIn the present study, mono‐ and multi‐material laser textured Ti6Al4V implants are manufactured and characterized in vivo to explore their applicability in orthopedic implants. Laser surface texturing is used for manufacturing grooved Ti6Al4V implants while a pressure‐assisted sintering technique is employed to impregnate beta‐tricalcium phosphate into grooves for an improved bioactivity. After implantation into Sprague Dawley rat's femur for 4 and 12 weeks, bone‐implant fixation and osseointegration are assessed, by performing push‐out tests and histological characterization. Histological characterization showed bone formation around all implants, characterized by immature bone at 4 weeks of implantation and a more mature bone after 12 weeks. The maximum push‐out forces are higher for the textured and multi‐material solution, when compared to non‐textured implants right after 4 weeks of implantation (p &lt; 0.05). After 12 weeks, multi‐material implant displayed higher fracture energy when compared to non‐textured implants (p &lt; 0.05). Results revealed that laser surface texturing and bioactive multi‐material solutions are highly effective to promote bone regeneration and enhance bone‐implant fixation for further application in orthopedic implants.

Peripheral ossifying fibroma: A 20-year retrospective study with focus on clinical and morphological features.

Background Peripheral Ossifying Fibroma (POF) is a reactive hyperplastic lesion that exclusively occurs in the gingiva and is characterized by the deposition of dystrophic calcification, cementum-like tissue, and immature and mature bone within the connective tissue. The objective of the present study was to perform a retrospective analysis of clinicopathologic features of POF.Material and Methods Clinical and histopathological data were obtained from biopsy records and histopathological reports from a Brazilian reference service in Oral Pathology (1999 - 2020). Morphological analysis was performed to evaluate features related to the mesenchymal component, inflammatory infiltrate, ulceration, and mineralized tissue.Results A total of 270 POFs were diagnosed during the study period. A higher frequency was observed in females (71.9%) between the third (22.9%) and fourth (23.3%) decades of life. The anterior upper gingiva (29.1%) was the most affected region. Mature (86.7%) and immature (52.6%) bone tissue were the most frequent. There was a significant association between immature bone deposition and lesions with size ≤ 1.7 cm (p = 0.041); immature bone and cement-like tissue deposition with an evolution time ≤ 16 months (p < 0.001); deposition of immature bone and mesenchymal hypercellularization (p < 0.001); deposition of dystrophic calcification and the presence of ulceration (p < 0.001).Conclusions The clinical characteristics corroborate the findings in the literature. The heterogeneous distribution and quantity of mineralized tissues found in the analyzed cases support the theory that the different mineralized tissues constitute a spectrum of clinical maturation of POF. Key words:Gingiva, gingival diseases, gingival hyperplasia, oral pathology, diagnosis.

The Role of Myeloid-Derived Suppressor Cells in Tumor Growth and Metastasis.

Myeloid-derived suppressor cells (MDSCs) are immature bone marrow-derived suppressive cells that are an important component of the pathological immune response associated with cancer. Expansion of MDSCs has been linked to poor disease outcome and therapeutic resistance in patients with various malignancies, making these cells potential targets for next-generation treatment strategies. MDSCs are classified into monocytic (M-MDSC) and polymorphonuclear/granulocytic (PMN-MDSC) subtypes that undertake distinct and numerous roles in the tumor microenvironment or systemically to drive disease progression. In this chapter, we will discuss how MDSC subsets contribute to the growth of primary tumors and induce metastatic spread by suppressing the antitumor immune response, supporting cancer stem cell (CSC)/epithelial-to-mesenchymal transition (EMT) phenotypes and promoting angiogenesis. We will also summarize the signaling networks involved in the crosstalk between cancer cells and MDSCs that could represent putative immunotherapy targets.

Autologous Tooth Dentin Graft: A Retrospective Study in Humans.

Background and Objectives: The aim of this study is to evaluate the efficacy of an autologous dentin graft, via extracted teeth that are processed into bacteria-free particulate dentin in a Smart dentin grinder and then grafted immediately into alveolus post extraction or into bone deficiencies. Materials and Methods: Ten healthy, partially edentulous patients with some teeth in the mandible were recruited in the study. After their own teeth were grinded, particulate teeth were placed in empty sockets and bone defects after teeth extractions. Furthermore, after three, six, 12 and 24 months, core samples using a 3 mm trephine were obtained. Results: At three months, the particles of grinded tooth were immersed inside a new connective tissue with a small new bone formation (16.3 ± 1.98). At six months, we observed small particles of dentin integrated in new immature bone, without inflammation in the soft tissue (41.1 ± 0.76). At twelve months, we observed a high amount of bone formation surrounding tooth particles (54.5 ± 0.24), and at twenty-four months, new bone, a big structure of bone, was observed with dentin particles (59.4 ± 1.23), statistically different when compared it with at three months. Conclusions: A particulate dentin graft should be considered as an alternative material for sockets’ preservation, split technique, and also for sinus lifting. One of the special characteristics after 24 months of evaluation was the high resorption rate and bone replacement without inflammation. This material could be considered as an acceptable biomaterial for different bone defects due to its osteoinductive and osteoconductive properties

Osteosarcoma of the Right Proximal Tibia: A Case Report

Osteosarcoma occurs mostly in adolescence, this being the primary bone tumor (malignant) formed by the production of immature bone. Immature bone cell's production occurs from the premature bone cells. The commonly used treatments form is lesions removal. Chemotherapy is also used to treat metastasis of the osteoid cells (cancerous). Sometimes the micro metastasis can't be diagnosed in time to can be cured with neoadjuvant chemotherapy. Pulmonary metastatic disease is the most common complication of the osteosarcoma (musculoskeletal cancer). I have presented a case of osteosarcoma of right proximal tibia in an18year old boy who come to the hospital for swelling and pain which were increasing during walking. Before that he hadn't any complaints in his knees. Magnetic resonance imaging was done by which the diagnosis was confirmed. After that, tumor resection was performed and post-operative chemotherapy was administered. The case report states that the adolescents age group should be properly monitored because they have the highest risk of suspicion by premature bone growth of osteoid.