Allogeneic Grafts Research Articles

USO DE ENXERTOS EM CIRURGIAS RECONSTRUTIVAS APÓS TRAUMAS GRAVES: UMA REVISÃO INTEGRATIVA

This article provides a comprehensive review of the use of grafts in reconstructive surgeries for patients with severe trauma, highlighting the differences among autologous, allogeneic, and synthetic grafts and their efficacy in specific contexts. Autologous grafts are known for their high integration rates and low immune rejection, while allogeneic and synthetic grafts expand therapeutic options, albeit with higher risks of complications. Technological advances, such as 3D bioprinting, allow for the customization of grafts, enhancing aesthetic and functional outcomes. However, these methods still face limitations, such as vascularization issues and immune rejection risks. This study emphasizes the importance of a careful and personalized selection of graft type to maximize patient quality of life and satisfaction. In conclusion, while autologous grafts remain the gold standard, the development of synthetic and bioprinted materials represents a promising frontier for reconstructive medicine.

Superior retention of aged fat graft by supplementing young adipose-derived stromal cells in a murine model.

In 2021, a meta-analysis showed fat graft retention varied from 26 to 83%. In a retrospective study including patients with Parry-Romberg syndrome, the younger age group had higher satisfaction scores (3.8 vs. 3.0) after fat grafting. Cell-assisted lipotransfer (CAL) could be an alternative to overcome the instability of volume loss; however, no study investigated its effect on old recipients. In an in vitro study, adipose-derived stromal cells (ASCs) from aged and young (52- and 8-weeks old) DsRed B6 mice were characterized by proliferation rates as percentages of Ki-67-positive cells. 68-week-old wild type B6 mice received 150 µL of green fluorescent protein fat (from 69-week-old B6 mice) mixed with saline, 3 x 105 aged or young DsRed ASCs (N, A, and Y groups, respectively) on the scalp (n = 6/group). After 8 weeks, graft volumes were evaluated using micro-computed tomography. Vessel densities were tracked by percentages of CD31 using immunofluorescence staining. Young ASCs showed higher proliferation than the aged (47.1% and 26.2%, respectively, p < 0.05). The Y group showed the highest graft retention (median: N = 41.0%, A = 52.2%, Y = 65.2%, p < 0.05) and percentage of blood vessels (median: N = 27.7%, A = 43.5%, Y = 54.7%, p < 0.05) among the three groups. CAL is effective with old recipients; higher effect was observed by supplementation with younger ASCs due to higher angiogenesis stimulation. However, this is autologous grafting model, further validation of safety, toxicity, and allogenic grafting is required. The results suggest that it is clinically possible to conduct CAL for old adults using autologous ASCs. However, further validation of using allogenic ASCs from young donors to improve graft retention in old adults is required.

The effect of radiotherapy, chemotherapy, and immunotherapy on fusion rate in spinal surgery using osteobiologics for patients with metastatic spinal disease: a systematic review.

To evaluate the impact that adjuvant therapies like radiotherapy, chemotherapy, and immunotherapy have on osteobiologic properties and bony regeneration in patients with metastatic spine disease (MSD) undergoing spinal fusion surgery. PubMed and ClinicalTrials.gov searches were performed. MSD patients undergoing fusion surgery with an osteobiologic and radiotherapy, chemotherapy and/or immunotherapy were included. Demographics, primary tumor, surgery, adjuvant treatments, osteobiologic type, fusion rates with scoring criteria, hardware failure, reoperation rates, follow-up, and survival were extracted. 1487 studies were screened, 20 included. 585 patients (464 with MSD) had fusion rates ranging from 17.9 to 100%. In the setting of radiotherapy, fusion rates of 10 studies using autologous bone graft (autograft), 5 studies using allogenic bone graft (allograft), 5 studies using combination autograft/allograft, 4 studies using biomaterial scaffolds (BMS), 3 studies using demineralized bone matrices (DBM), and 1 study using growth factors (GF), were 50-100%, 17.9-100%, 57.8-100%, 52.9-100%, 20-100%, and 100%, respectively. A higher incidence of fusion in patients with autograft or allograft receiving stereotactic body radiotherapy (SBRT) at lower biologically effective doses (BED) and at least 1-month postoperatively was noted. Chemotherapy had no impact on fusion. No studies evaluated the impact of immunotherapy on fusion. SBRT at lower doses given greater than 1-month postoperatively may enhance bony fusion in patients receiving autograft, allograft, or autograft/allograft. Chemotherapy may delay bony fusion without affecting overall fusion rates. Preclinical studies suggest immunotherapy may prevent osteolysis and promote osteogenesis, but no studies have yet evaluated the clinical impact of these findings on spinal fusion. Further research is needed on osteobiologics in bony regeneration in the MSD population.

Repeated CXCR4 Blockade by Plerixafor Attenuates Transplant Vasculopathy in Murine Aortic Allografts.

Plerixafor, a hematopoietic stem cell mobilization agent, increases the peripheral blood content of effector and regulatory T cells and may have beneficial effects on cardiac allograft vasculopathy. The aim of the current study was to evaluate its effects in a murine aortic allograft model using different application procedures. Allogeneic donor aorta grafts (n = 8/group) from C57BL/6 mice(H2b) were abdominally transplanted into CBA mice (H2k). Plerixafor application was performed either continuously for 14 d using abdominally implanted osmotic pumps (1 mg/kg/d) or i.p. with a single dose (1 and 5 mg/kg) on day 0 or pulsed injections of 1 mg/kg on days 0, 7, 14, and 21. Cell distribution was monitored by FACS. Aortic grafts were evaluated for neointima development by Elastica-van-Gieson on day 30. Immunofluorescence and intragraft gene expression analysis were performed. On day 14, significantly fewer hematopoietic stem cells were found in the bone marrow of all plerixafor-treated mice. In the pulsed application group, significantly more hematopoietic stem cells were found in the peripheral blood on day 14 (0.045 ± 0.002%; p < 0.01 [pulsed]; versus 0.0068 ± 0.002% [control]) and also more regulatory T cells. PCR revealed lower inflammatory cytokines. The luminal occlusion was significantly reduced in the pulsed treated group (33.65 ± 8.84 versus 53.13 ± 12.41) going along with decreased neointimal CD4+ T cell and plasmacytoid dendritic cell infiltration, as well as less smooth muscle cell proliferation. The application of plerixafor attenuates chronic rejection in aortic allografts via immunomodulatory effects. Injection of repeated low-dose plerixafor is the most effective application form in the aortic transplant model.

Enhanced alveolar ridge preservation with hyaluronic acid-enriched allografts: a comparative study of granular allografts with and without hyaluronic acid addition

PurposeRidge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition.MethodsIn this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation.ResultsVertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as “Success” according to the ICOI scheme, with no differences in implant quality between the two study groups.ConclusionsImproved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation.

Thrombosis and anticoagulation after portal vein reconstruction during pancreatic surgery – A systematic review

ObjectiveTo comprehensively assess thrombotic events and their clinical impact in patients receiving pancreatic surgery with venous resection and reconstruction. BackgroundPortal vein (PV, including the portal vein and superior mesenteric vein) resection and reconstruction enables surgical removal of borderline-resectable and locally advanced pancreatic cancer. Thrombosis of the reconstructed PV represents a major source of early postoperative and long-term morbidity and mortality. No universally accepted standard for anticoagulation exists. Here, we aimed to assess early and late thrombosis rates after PV reconstruction with special regard to type of PV reconstruction as well as anticoagulation regimen. MethodsPRISMA guidelines were followed. Studies reporting on PV resection and reconstruction providing data on thrombosis rates were included. The following parameters were assessed: Study type, year of publication, number of patients, type/number of PV reconstruction, follow-up period, postoperative mortality, rate of thrombosis of reconstructed PV axis, intraoperative blood loss, and anticoagulation. Results23 studies with 2751 patients were included in the final analysis. 670 patients received tangential resection of the PV with venorrhaphy or patch repair, 1505 patients had segmental resection with end-to-end reconstruction, and 576 patients received reconstruction with an interposition graft/conduit. The pooled overall thrombosis rate was 15%. Reconstruction of tangential defects with either venorrhaphy or patch repair as well as end-to-end repair of segmental defects resulted in a thrombosis rate of 12%. Subgroup analysis according to the type of graft reconstruction revealed the highest occlusion rates of 55% in patients with allogeneic grafts, followed by up to 27% in patients with synthetic PV conduits. Autologous conduits had a thrombosis rate of 10%. Early thrombotic events were detected in 5% of patients after venorrhaphy/patch reconstruction and end-to-end reconstruction. Early events were most common in the allogeneic graft subgroup (22%), followed by synthetic conduits (15%). There were fewer early events in the autologous graft group (7%). Early PV thrombosis was associated with relevant mortality of up to 26%. Anticoagulation regimens varied between studies. ConclusionThe overall rate of thrombosis after portal vein resection is low. However, among different reconstruction techniques, allogeneic interposition grafts/conduits had the highest thrombosis rates among the different types of reconstruction after PV resection. No specific anticoagulation strategy can be considered beneficial on the basis of the existing literature. Mini-AbstractThrombosis of the reconstructed portal vein (PV) after PV resection in pancreatic surgery represents a relevant source of major morbidity and mortality. In this systematic review, while we observed an overall low thrombosis rate following PV resection, reconstruction with allogeneic grafts harbors the highest risk of postoperative thrombosis. Early thrombosis was most common after reconstruction with allogeneic grafts and associated with postoperative mortality. Anticoagulation strategies vary greatly among different studies.

Use of tricortical iliac crest allograft for augmentation of depressed lateral tibial plateau fracture: a surgical technique.

Lateral tibial plateau fractures with significant articular depression and metaphyseal comminution in the setting of osteoporosis are challenging to manage. The subchondral bone defect and capacious cancellous void after surgical elevation of the articular surface is usually filled with nonstructural graft such as autologous cancellous bone graft, allogenic cancellous bone graft, or bone graft substitutes. Reports have shown a high rate of subsidence with these grafts when patients start to bear weight and ultimately failure of the construct. Structural grafts demonstrated stronger mechanical properties and lower subsidence rates. The purpose of this note is to describe a novel surgical technique using structural tricortical iliac crest allograft for the treatment of osteoporotic depressed lateral tibia plateau fracture.

Oral Chronic Graft-Versus-Host Disease: Pathogenesis, Diagnosis, Current Treatment, and Emerging Therapies.

Chronic graft-versus-host disease (cGvHD) is a multisystem disorder that occurs in recipients of allogeneic hematopoietic (alloHCT) stem cell transplants and is characterized by both inflammatory and fibrotic manifestations. It begins with the recognition of host tissues by the non-self (allogeneic) graft and progresses to tissue inflammation, organ dysfunction and fibrosis throughout the body. Oral cavity manifestations of cGVHD include mucosal features, salivary gland dysfunction and fibrosis. This review synthesizes current knowledge on the pathogenesis, diagnosis and management of oral cGVHD, with a focus on emerging trends and novel therapeutics. Data from various clinical studies and expert consensus are integrated to provide a comprehensive overview.

THE ROLE OF PERICYTES IN BONE TISSUE REGENERATION AND THERAPEUTIC APPLICATIONS

The regeneration of massive bone defects poses a significant challenge in traumatology and orthopedics, often requiring bone grafting procedures following tumor resection, surgery, or severe injury. Current treatment methods include autologous and allogeneic bone grafts, as well as bone substitutes. While autologous transplantation is considered the standard, it is limited by donor site morbidity and availability. Allogeneic transplantation presents risks such as graft rejection and disease transmission. Bone substitutes may not fully restore bone defects. Tissue-engineered biomaterials offer promise for effective regeneration, utilizing stem cells, growth factors, and scaffolds. Adipose tissue, rich in mesenchymal stem cells and perivascular stem cells (pericytes), is a promising cell source for tissue engineering. This thesis explores the therapeutic potential of pericytes combined with various biological carriers and stimulating factors to enhance bone tissue regeneration. Pericytes, contractile cells surrounding small blood vessels, are crucial for vessel integrity and blood flow regulation. They express markers like α-SMA and PDGFR-β and participate in angiogenesis, immune function, and tissue repair. Interactions with endothelial cells via signaling pathways involving molecules like VEGF and TGF-β are vital for vessel formation and stability. With their multipotent nature, pericytes show promise for regenerative medicine. Ongoing research is essential to address challenges in pericyte biology, including identification and understanding their roles in tissue regeneration. Studies highlight the potential of adipose tissue-derived pericytes in bone regeneration, particularly CD146+ pericytes, showing efficacy in spinal fusion and nonunion fracture treatment when combined with DBM. Preclinical studies confirm their effectiveness, especially when incorporated into various scaffold materials. Clinical studies using adipose-derived stem cells and autologous microfragmented adipose tissue have shown promise, with pericyte-enriched fractions holding potential for improved outcomes. Future research into pericyte application, combined with growth factors and scaffolds, could significantly advance bone tissue regeneration and regenerative medicine. Human pericytes show promise for bone tissue regeneration due to their mesenchymal stem cell properties and role in vascular stabilization. Injectable hydrogels are crucial for bone tissue engineering, with various biomaterials developed for this purpose. Studies using injectable hydrogels with pericytes have demonstrated their efficacy in accelerating bone regeneration in different models. Further advancements in injectable hydrogel technology incorporating stem cells and osteoinductive factors are needed for more efficient bone tissue restoration.

Induced pluripotent stem cell-derived mesenchymal stem cells enhance acellular nerve allografts to promote peripheral nerve regeneration by facilitating angiogenesis.

Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells. However, adult tissue-derived mesenchymal stem cells encounter various obstacles, including limited tissue sources, invasive acquisition methods, cellular heterogeneity, purification challenges, cellular senescence, and diminished pluripotency and proliferation over successive passages. In this study, we used induced pluripotent stem cell-derived mesenchymal stem cells, known for their self-renewal capacity, multilineage differentiation potential, and immunomodulatory characteristics. We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury. Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation. Furthermore, the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats. Additionally, our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization. Collectively, our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats, offering promising therapeutic strategies for clinical translation.

Radiologic and Histological Evaluation of Allogenic Bone graft Blocks in Bounded Anterior Maxillary Alveolar Ridge Defects

Radiologic and Histological Evaluation of Allogenic Bone graft Blocks in Bounded Anterior Maxillary Alveolar Ridge Defects

A preliminary study of the mechanical properties of 3D-printed personalized mesh titanium alloy prostheses and repair of hemi-mandibular defect in dogs.

This study is a preliminary investigation exploring the mechanical properties of three-dimensional (3D)-printed personalized mesh titanium alloy prostheses and the feasibility of repairing hemi-mandibular defects. The ANSYS 14.0 software and selective laser melting (SLM) were used to produce personalized mesh titanium alloy scaffolds. Scaffolds printed using different parameters underwent fatigue property tests and scanning electron microscopy (SEM) of the fracture points. Models of hemi-mandibular defects (encompassing the temporomandibular joint) were created using beagle dogs. Freeze-dried allogeneic mandibles or 3D-printed personalized mesh titanium alloy prostheses were used for repair. Gross observation, computed tomography (CT), SEM, and histological examinations were used to compare the two repair methods. The prostheses with filament diameters of 0.5 and 0.7 mm could withstand 14,000 times and >600,000 cycles of alternating stresses, respectively. The truss-structure scaffold with a large aperture and large aperture ratio could withstand roughly 250,000 cycles of alternating forces. The allogeneic mandible graft required intraoperative shaping, while the 3D-printed mesh titanium alloy prostheses were personalized and did not require intraoperative shaping. The articular disc on the non-operated sides experienced degenerative changes. No liver and kidney toxicity was observed in the two groups of animals. The 3D-printed mesh titanium alloy prostheses could effectively restore the shape of the mandibular defect region and reconstruct the temporomandibular joint.

Biomechanical Evaluation of the Osseointegration Levels of Implants Placed Simultaneously With Tibia, Femur, and Jaw Allogeneic Bone Grafts.

In implant-supported prosthetic treatments, the jaw bones may not always have enough bone to accommodate implants. Allogeneic grafts can also be preferred as an alternative to autogenous grafts in cases of vertical and horizontal bone deficiencies. The aim of this study is to evaluate the osseointegration levels of lathe-faced titanium implants placed together with allogeneic bone tissue transplants obtained from tibia, femur, and mandible bones using a biomechanical method. Twenty-eight female Sprague Dawley rats were included in the study. The subjects were divided into groups where bone transplantations were performed together with implant placement from the tibia (n=7), femur (n=7), and lower jaw (n=7) regions. Four rats (left and right) were used as donors. Grafts, along with implants, were surgically placed in the corticocancellous part of the metaphyseal parts of the tibia bones of rats. At the end of the 2-week experimental setup, all rats were killed, and the implants and surrounding bone tissues were subjected to biomechanical reverse torque analysis (N/cm), no statistical difference was detected in terms of bone-implant fusion between the groups in which the femur and tibia bones were transplanted (P>0.05), while the bone-implant fusion value in the group in which the lower jaw bone was transplanted was found to be statistically higher than the femur and tibia bones (P<0.05). Based on the limited results of this study, it can be thought that the lower jaw allogeneic jawbone has a higher osseointegration potential than allogeneic grafts obtained from the femur and tibia.

MgO-enhanced β-TCP promotes osteogenesis in both in vitro and in vivo rat models

Allogeneic bone grafts are used to treat bone defects in orthopedic surgery, but the osteogenic potential of artificial bones remains a challenge. In this study, we developed a β-tricalcium phosphate (β-TCP) formulation containing MgO, ZnO, SrO, and SiO2 and compared its bone-forming ability with that of β-TCP without biological elements. We prepared β-TCP discs with 60% porosity containing 1.0 wt% of these biological elements. β-TCP scaffolds were loaded with bone marrow-derived mesenchymal stem cells (BMSC) from 7-week-old male rats and cultured for 2 weeks. ALP activity and mRNA expression of osteogenic markers were evaluated. In addition, scaffolds were implanted subcutaneously in rats and analyzed after 7 weeks. In vitro, the MgO group showed lower Ca concentrations and higher osteogenic marker expression compared to controls. In vivo, the MgO group showed higher ALP activity compared to controls, and RT-qPCR analysis showed significant expression of BMP2 and VEGF. Histopathology, fluorescent immunostaining, and micro-CT also showed relatively better bone formation in the MgO group. β-TCP with MgO may enhance bone morphology in vitro and in vivo and improve the prognosis of patients with substantial and refractory bone defects.

Reconstruction of the medial collateral ligament complex with aflat semitendinosus auto- or allograft

Replacement of superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with an allograft. Chronic 3° isolated medial instability and combined anteromedial or posteromedial instability. Infection, open growth plates, restricted range of motion (less than E/F 0-0-90°). Longitudinal incision from medial epicondyle to superficial pes anserinus and exposure of the medial collateral ligament complex. Thawing of the allogeneic semitendinosus tendon graft at room temperature, reinforcement of the tendon ends with sutures and preparation of atwo-stranded graft. Placement of guidewires in the sMCL and POL insertions and control with image intensifier. Tunnel drilling. Pulling the graft loop into the femoral bone tunnel and fixation with aflip button. Pulling the two graft ends into the tibial tunnels. Tibial fixation by knotting the suture ends in a20° flexion on the lateral cortex. Suture the tendon bundles to the remaining remnants of the medial collateral ligament complex to adopt the flat structure of the natural medial collateral ligament complex. Six weeks partial weight-bearing, immediately postoperatively splint in the extended position, after 2weeks movable knee brace for another 4-6weeks. Mobility: 4weeks 0-0-60, 5th and 6th weeks 0-0-90. From 2015-2021, this surgical procedure was performed in 19patients (5women, 14men, age34years). Mean Lysholm score at follow-up after at least 2years was 89 (76-99) points. In 6patients, there was restricted range of motion 3months postoperatively, which resulted in further therapy (3 ×systemic cortisone therapy, 3 ×arthroscopically supported manipulations under anesthesia).

P4. Effect of autologous vs allogeneic cell-based grafts on early clinical and radiographic outcomes in LLIF surgery

P4. Effect of autologous vs allogeneic cell-based grafts on early clinical and radiographic outcomes in LLIF surgery

Posttraumatic growth disturbances of the distal radius in childhood

Fractures of the distal radius in childhood are frequent but rarely lead to relevant growth disturbances. The experiences of apediatric trauma center over 15years are exemplarily presented and discussed. Osteotomies of the distal radius were selected and the clinical and radiological findings were recorded and analyzed. Posttraumatic growth disturbances were corrected in 10 cases with amedian age of 13 ½ years. In six cases an iatrogenic cause was also possible. In two cases callus distraction with secondary palmar plate osteosynthesis was used for consolidation. In eight cases primary ad hoc corrections were carried out using palmar plate osteosynthesis (six with iliac crest and two with allogeneic grafts). In five cases the distal ulnar growth plate was also addressed. During follow-up breakage of one plate was registered. After an average of 31months postoperatively, 9 children had full range of motion (ROM) and in 1 case there was an extension deficit of 10o. It is important to evaluate the cause of the mostly partially inhibiting growth disturbances to draw preventive conclusions. From a clinical perspective the visible deformity is given priority and the pain and functional limitations are less relevant. The indications for corrective surgery must include the age of the patient, remaining growth potential, size and localization of the growth plate bridge, the deformity and the individual wishes of patients and parents. In most cases afull correction is possible with palmar plate osteosynthesis and an iliac crest graft. External fixation and callus distraction is an alternative in cases where the correction is more extensive. The distal ulnar growth plate should be controlled concerning further growth potential before hardware removal.

BONE GRAFTS IN THE RECONSTRUCTION OF LE FORT 1 FRACTURES

Fractures of the midface are complex injuries that affect important bone structures such as the maxilla, zygoma and naso-orbito-ethmoidal complex (NOE), being classified by René Le Fort 1nto three categories: Le Fort 1, II and III. Such fractures generally result from car accidents, assaults, falls, sports and work accidents.Treatment aims at complete rehabilitation of the patient, stabilizing the fragments and restoring masticatory function, dental occlusion and anatomical relationships. Different approaches can be used for this purpose, such as osteotomies and bone grafts. Bone grafts provide stability to fractures, create a foundation for dental rehabilitation, and reduce the risk of complications. There are many options available such as autogenous, allogeneic, xenogeneic and alloplastic grafts. The autogenous graft is taken from the patient himself and is considered the gold standard, although obtaining it may increase the morbidity of the procedure. Each graft category has its advantages and disadvantages, and it is essential to consider factors such as biocompatibility, osteoinductive and osteoconductive capacity, in addition to market availability and possible complications. Selection of the ideal material is exceptionally important for the success of the procedure. Autogenous and allogeneic grafts have been widely used, viable alternatives are xenogeneic and alloplastic grafts. However, more studies are needed to assess its long-term effectiveness. The procedure for placing bone grafts in a hospital in the dental area is carried out by oral and maxillofacial surgeons and has open and minimally invasive techniques. Recovery time varies according to the type of graft and the extent of the procedure, requiring adequate post-operative care.A multidisciplinary approach, as well as collaboration between different medical specialties, are very important for a comprehensive and personalized assessment of the patient, ensuring an efficient intervention and a complete recovery, not only physical, but also emotional and social.

Evaluation of alveolar ridge values with autogenous tooth graft and the provocative venture of allogeneic tooth graft from family members

Background Preserving the structural integrity of the alveolar ridge is paramount in ensuring the success of dental implant procedures and optimizing both aesthetic and physiological outcomes. This study aims to evaluate the efficacy of autologous dental grafting and explore intriguing results achieved through the utilization of allogeneic dental grafts obtained from a familial participant within the study’s framework. Methods Eleven patients necessitating bilateral dental extractions were enrolled in the study. Ten patients underwent autologous dental grafting on one side, while the contralateral side remained untreated. In the eleventh case, one side received autogenous dental grafting, while the other side was augmented with an allogeneic graft sourced from the patient’s son. Outcomes were monitored over a four-month period. Results Autogenous dental grafting led to a significant enhancement in bone density values and a reduction in osseous absorption rates(P&lt;0.05) when compared to untreated sites among the ten patients who underwent the procedure. However, notable advancements were observed in patient 11 who received an allogeneic dental graft from a familial donor, suggesting potential superiority over autologous grafting in promoting bone regeneration. These findings underscore the promising prospects of employing allogeneic dental grafts sourced from family members to achieve optimal outcomes in alveolar ridge preservation. Conclusions The study underscores the significance of utilizing autologous dental grafts for preserving alveolar ridge dimensions. Importantly, the noteworthy improvement observed in patient outcomes resulting from the use of allogeneic dental grafts compared to autologous grafts raises several inquiries, particularly concerning the potential relationship between the patient and the donor. Trial registration The study is registered as a BRAZILIAN CLINICAL TEST RECORD (ReBEC): U1111-1305-2793 on 28-05-2024 ( https://ensaiosclinicos.gov.br/rg/RBR-65qchvs).

Early graft-infiltrating lymphocytes are not associated with graft rejection in a mouse model of skin transplantation.

Graft-infiltrating lymphocytes (GILs) play an important role in promoting rejection after organ transplantation. We recently reported that GILs that accumulated up to 3 days post-transplantation did not promote rejection, whereas GILs present 3-5 days post-transplantation promoted rejection in a mouse heart transplantation model. However, the immunological behaviour of GILs in murine skin transplantation remains unclear. GILs were isolated on days 3, 5 or 7 post-transplantation from C57BL/6 (B6) allogeneic skin grafts transplanted onto BALB/c mice. BALB/c Rag2-/- γc-/- mice (BRGs) underwent B6 skin graft transplantation 10 weeks after adoptive transfer of day 3, 5, or 7 GILs. BRGs reconstituted with day 5 or 7 GILs completely rejected B6 grafts. However, when B6 grafts harvested from recipient BALB/c mice on day 5 or 7 were re-transplanted into BRGs, half of the re-transplanted day 5 grafts established long-term survival, although all re-transplanted day 7 grafts were rejected. BRGs reconstituted with day 3 GILs did not reject B6 grafts. Consistently, re-transplantation using day 3 skin grafts resulted in no rejection. Administration of anti-CD25 antibodies did not prevent the phenomenon observed for the day 3 skin grafts. Furthermore, BRGs reconstituted with splenocytes from naïve BALB/c mice immediately rejected the naïve B6 skin grafts and the re-transplanted day 3 B6 grafts, suggesting that day 3 GILs were unable to induce allograft rejection during the rejection process. In conclusion, the immunological role of GILs depends on the time since transplantation. Day 3 GILs had neither protective nor alloreactive effects in the skin transplant model.