Allogeneic Bone Grafts Research Articles

Osteoclastoma of bone: Role of extended curettage with allogenic bone grafting

Background: Mesenchymal stromal cells are origin for benign tumor osteoclastoma of bone. Different location of presentations with varied manifestations is a unique feature of osteoclastoma. Extended curettage of the lesion and supplementary allogenic bone grafting in selected cases is widely used treatment regimen. Selection of cases is important for successful outcome using this as a treatment protocol. Our study with 30 cases aims in selection of cases for successful outcome with this treatment protocol. Materials and Methods: Biopsy proven (core and open biopsy) 30 cases of osteoclastoma are selected. The cases are evaluated clinically, radiographically, CT &MRI scan and by histology. Campanancci grading and Enneking staging was used in the study. Chi square tests, Mann Whitney test and ANOVA were used for statistical analysis. Tumors with cortical breach which is confined to one surface and cortical breach less than one third of circumference were managed by extended curettage and bone grafting.Results: The average age of presentation was 25 years. Distal femur is the commonest site (16 cases) followed by upper end of tibia (12 cases) and 2 cases are from distal radius. Pathological fractures were seen in 2 cases. 4 tumors had less than 5 mm of subchondral bone free of tumor. The average follow up period was 18.6 months (range 2-84). 4 cases of recurrence were seen in a grade III recurrent distal femur lesion (3) and proximal tibia group (1) in the intralesional curettage group.Conclusion: Extended curettage with allogenic bone grafting is a reliable method with good functional outcome with less complications than other methods (enbloc excision) whenever we stick on to principles of tumor surgery with proven guidelines of case selection. Recurrence can always be treated with recurettage.

An evaluation of biomaterials and osteobiologics for arthrodesis achievement in spine surgery.

An increasing variety of orthobiologic materials, including autologous and allogeneic bone graft, bone marrow aspirate, demineralized bone matrix, ceramics, and growth factors are available to the spine surgeon. Although autologous bone graft remains the gold standard material, concerns for failure in achieving fusion have prompted evaluation of current and new biologic materials. As such, this review attempts to summarize the available biologic materials with their pertinent characteristics, advantages, disadvantages, and primary uses.

Biologization of Allogeneic Bone Grafts with Polyphosphate: A Route to a Biomimetic Periosteum

AbstractThe physiological polyphosphate (polyP), released primarily from platelets after bone fractures, acts as a donor for metabolic energy and as a phosphate source for bone mineralization. In this study allogeneic, decellularized bone samples are biologized with a layer of inorganic polyP by submersion of human femur cortex slices into a solution of Na‐polyP. Then polyP coat is modified by exposure to CaCl2, resulting in in situ formation of amorphous Ca‐polyP microparticles (Ca‐polyP‐MP; diameter of ≈155 nm). Energy dispersive X‐ray spectroscopy analysis of the Ca‐polyP‐MP coat reveals a Ca:P molar ratio of ≈0.78, while the nonmodified bone cortex is characterized by a Ca:P ratio of ≈1.52. An ionic shift promotes the strong binding of the polyP to the bone. While the polyP modification only insignificantly increases the hardness of the bone sample, without changing the elastic surface properties, the polyP‐modified bone provides a very favorable substrate for SaOS‐2 cells to attach and to mineralize. In the presence of medium/serum the polyP coat transforms to a functionally active coacervate. The cells, attached to the polyP coat, show a marked spreading behavior and became entrapped into the polyP‐coacervate. The results suggest that regenerative‐active polyP might be of potential use in healing of bone.

Histological and immunohistochemical comparison of two different allogeneic bone grafting materials for alveolar ridge reconstruction: A prospective randomized trial in humans.

ABSTRACTBackgroundPreclinical studies have hypothesized a possible immunological reponse to allogeneic materials due to detection of remnants of potential immunogenic molecules. However, their impact on integration, bone remodeling and immunological reaction after the augmentation procedure is largely unknown and a direct correlation of analytical data and evaluation of human biopsies is missing.PurposeThe present study aimed to compare two commercially available allogeneic materials regarding their content of cellular remnants as well as the bone remodeling, and integration and potential immunologic reactions on a histological and immunohistochemical level, integrating also in vitro analytical evaluation of the specific batches that were used clinically.Materials and MethodsTwenty patients were randomly assigned to treatment with Maxgraft or Puros for lateral ridge augmentation in a two‐stage surgery. After a mean healing period of 5 months, implants were placed and biopsies were taken for histological, immunhistochemical, and histomorphometrical evaluation regarding bone remodeling and inflammation, protein concentrations in vitro and the presence of MHC molecules of the same batches used clinically.ResultsNo differences in clinical outcome, histological, immunohistochemical, and in vitro protein analysis between the two bone grafting materials were observed. Active bone remodeling, amount of newly formed bone, and residual grafting material was independent of the materials used, but varied between subjects. MHC1 residues were not detected in any sample.ConclusionsWithin the limitations of this study, both tested materials yielded equivalent results in terms of clinical outcome, new bone formation, and lack of immunological potential on a histological and immunohistochemical level.

Acetabular reconstruction for primary and revision total hip arthroplasty using Kerboull-type acetabular reinforcement devices-case-control study with factors related to poor outcomes of surgery.

Kerboull-type acetabular support rings (KT) and allogenic bone graft were used for severe periacetabular bone loss with primary and revision total hip arthroplasty (THA). The purpose of this case–control study is to evaluate the risk factors related to poor outcomes of surgery.Sixty patients underwent primary THA and revision THA using allogenic bone graft with KT for large acetabular deficiency. These patients were retrospectively evaluated postoperatively and followed-up by radiograph. The minimum follow-up period was 4 years and averaged 7 years. A radiological failure was defined by the following criteria:1)substantial migration defined as change in the angle of inclination of more than 5 degrees or migration of more than 5 mm,2)breakage of the screw or device,3)acetabular revision due to aseptic loosening.Expected risk factors were defined as female, age >75 years, body mass index (BMI) >25%, medical history of hypertension, renal failure, liver steatosis, diabetes, hyperlipidemia, cardiac infarction, smoking, American Academy of Orthopedic Surgery (AAOS) classification III or IV, bleeding>500 mL, time of surgery >3hours, high hip center-type KT, inclination of KT >45 degrees, screw angle >25 degrees, morselized bone graft, Kawanabe's classification stage 3 or 4 and revision surgery. Nineteen hips (31.6%) revealed radiological failure according to our criteria, and revision THA was performed in 2 hips (3.3%). In the statistical analysis, morselized bone graft and high hip center-type KT were identified as factors of poor outcomes of surgery.

Risk Factors of Allogenous Bone Graft Collapse in Two-Level Anterior Cervical Discectomy and Fusion.

ObjectiveAnterior cervical discectomy and fusion (ACDF) is commonly used surgical procedure for cervical degenerative disease. Among the various intervertebral spacers, the use of allografts is increasing due to its advantages such as no harvest site complications and low rate of subsidence. Although subsidence is a rare complication, graft collapse is often observed in the follow-up period. Graft collapse is defined as a significant graft height loss without subsidence, which can lead to clinical deterioration due to foraminal re-stenosis or segmental kyphosis. However, studies about the collapse of allografts are very limited. In this study, we evaluated risk factors associated with graft collapse. MethodsWe retrospectively reviewed 33 patients who underwent two level ACDF with anterior plating using allogenous bone graft from January 2013 to June 2017. Various factors related to cervical sagittal alignment were measured preoperatively (PRE), postoperatively (POST), and last follow-up. The collapse was defined as the ratio of decrement from POST disc height to follow-up disc height. We also defined significant collapses as disc heights that were decreased by 30% or more after surgery. The intraoperative distraction was defined as the ratio of increment from PRE disc height to POST disc height. ResultsThe subsidence rate was 4.5% and graft collapse rate was 28.8%. The pseudarthrosis rate was 16.7% and there was no association between pseudarthrosis and graft collapse. Among the collapse-related risk factors, pre-operative segmental angle (p=0.047) and intra-operative distraction (p=0.003) were significantly related to allograft collapse. The cut-off value of intraoperative distraction ≥37.3% was significantly associated with collapse (p=0.009; odds ratio, 4.622; 95% confidence interval, 1.470-14.531). The average time of events were as follows: collapse, 5.8±5.7 months; subsidence, 0.99±0.50 months; and instrument failure, 9.13±0.50 months. ConclusionWe experienced a higher frequency rate of collapse than subsidence in ACDF using an allograft. Of the various preoperative factors, intra-operative distraction was the most predictable factor of the allograft collapse. This was especially true when the intraoperative distraction was more than 37%, in which case the occurrence of graft collapse increased 4.6 times. We also found that instrument failure occurs only after the allograft collapse.

Immediate Insertion of Dental Implants Immediate Insertion in Bilateral Traumatic Bone Cysts With or Without a Bone Grafting Material: A 5-Year Follow-Up Case Report.

This case report describes the rehabilitation of a patient who received dental implants in traumatic bone cyst areas (TBC). A 24-year-old male patient sought dental treatment for the bilateral absence of the mandibular second premolars. Radiographic examination revealed bilateral large radiolucent images in the mandible body. Surgical exploration confirmed the diagnosis of TBC. Rehabilitation with dental implants was performed using different approaches on each side. One cystic cavity was filled with blood clot and allogenic bone graft; the other was filled only with blood clot. After 5 years, the implants are osseointegrated and functioning. The filling of the traumatic bone cyst cavity with local blood clot in contact with the implant presented clinical and radiographic success similar to that obtained with filling with bone graft in the same patient. Thus, in this patient, the blood clot-only approach can be considered as a viable, safe-low cost alternative to blood clot and grafting material.

Endoscopic-assisted enucleation of large mandibular odontogenic cysts.

Traditional enucleation of large mandibular odontogenic cysts is an invasive method, which might be associated with several complications. The purpose of this study was to evaluate the clinical outcome of endoscope-assisted enucleation of large mandibular cysts. Fifty-seven patients with large mandibular odontogenic cysts were enrolled in this study. Patients were divided into 2 groups as follows: (1) 25 patients who were treated with traditional enucleation and (2) 32 who underwent endoscope-assisted enucleation. Allogeneic bone grafting was applied in all cases. All patients successfully underwent the operation. The follow-up period ranged from 16 to 28 months. Recurrence was found in 2 patients (8%) in the traditional enucleation group; no recurrence was observed in patients in the endoscope-assisted enucleation group. Permanent mandibular nerve palsy was found in 2 patients in the traditional enucleation group; only 2 cases of temporary mandibular nerve palsy were observed in the endoscope-assisted enucleation group. Endoscope-assisted enucleation of large mandibular odontogenic cysts proved to be an effective treatment method, providing complete enucleation of the cystic lesion while preserving surrounding tissue.

Effect of Electrohydraulic Extracorporeal Shockwave Therapy on the Repair of Bone Defects Grafted With Particulate Allografts.

This study determined the effect of electrohydraulic extracorporeal shockwave therapy (ESWT) on the healing of mandible defects repaired using particulate allogenic bone grafts. This study included 20 male Wistar rats aged 12 weeks. In all the animals, a critical-sized defect of 4-mm diameter was created in the mandible and the defect area was filled with particulate allograft. Next, the rats were divided into 2 groups, allograft (G) (n = 10) and allograft + ESWT (GE) (n = 10). On days 3, 5, and 7 after the grafting, rats in the GE group received ESWT involving 200 pulses with an energy flux density of 0.19 mJ/mm. Five rats in each group were sacrificed at the end of week 4 and at the end of week 8. Defect areas were examined radiologically by performing high-resolution computed tomography and stereologically by using the Cavalieri method. Obtained data were compared by performing statistical analysis. Radiological evaluation showed that bone density was higher in rats in the G group than in those in the GE group at week 4. In contrast, bone density was higher in rats in the GE group than in those in the G group at week 8. Stereological examination showed that new bone, connective tissue, and capillary volumes were higher in rats in the GE group than in those in the G group at both weeks 4 and 8. The authors' results indicate that repeated doses of ESWT accelerate the healing of bone defects repaired using allogenic bone grafts.

MIS approaches in the cervical spine.

Minimally invasive surgical approaches for the treatment of spinal pathologies have accelerated over the past three decades and resulted in superior functional outcomes with less complications. Yet cervical pathologies have been slower to gain traction for multiple anatomical factors and its "high-risk" profile. Various minimally invasive techniques for cervical disease have now been described and validated in long-term studies with comparable outcomes to traditional open approaches and concomitant reduction in morbidity and socioeconomic costs. Transnasal operations can be used to treat ventral upper cervical disease, circumventing traditional and morbid transoral approaches. Posterior-based focused treatments for radiculopathy and myelopathy such as tubular-guided foraminotomies and unilateral laminotomies for bilateral cord decompression have also been described and becoming increasingly less invasive. Cervical fusions can now be performed percutaneously through modified, stand-alone facet joint cages that can be packed with allogeneic bone graft. These advances have been facilitated by the development of intraoperative imaging technologies (intraoperative CT) and 3-dimensional stereotactic navigation software. While this review focuses on these procedures and evidence-based outcomes data, the future for MIS applications in cervical spine surgery will continue to evolve over the coming years with wider indications and technological adjuncts.

Orthobiologics in minimally invasive lumbar fusion

Minimally invasive (MI) spine surgery continues to gain popularity with patients and surgeons for its potential to decrease operative time and avoid complications commonly associated with open surgery. In the face of a changing surgical landscape, selecting the appropriate implant material to be used in MI lumbar fusion procedures will remain critically important. Various orthobiologic materials are available for use, including autologous and allogeneic bone graft, bone marrow aspirate (BMA), demineralized bone matrix (DBM), ceramics, and growth factors. The purpose of this review is to summarize the use and efficacy of currently available products, as well as highlight the development of novel therapeutic options.

Modified trapdoor procedures by surgical dislocation approach to treat chondroblastoma of the femoral head.

The aim of this study was to evaluate the efficacy of the surgical dislocation approach and modified trapdoor procedure for the treatment of chondroblastoma of the femoral head. A total of 17 patients (ten boys, seven girls; mean age 16.4 years (11 to 26)) diagnosed with chondroblastoma of the femoral head who underwent surgical dislocation of the hip joint, modified trapdoor procedure, curettage, and bone grafting were enrolled in this study and were followed-up for a mean of 35.9 months (12 to 76). Healing and any local recurrence were assessed via clinical and radiological tests. Functional outcome was evaluated using the Musculoskeletal Tumour Society scoring system (MSTS). Patterns of bone destruction were evaluated using the Lodwick classification. Secondary osteoarthritis was classified via radiological analysis following the Kellgren-Lawrence grading system. Steinberg classification was used to evaluate osteonecrosis of the femoral head. The epiphyseal plate was open, closing, and closed in five, five, and seven patients, respectively. In total, eight, six, and three patients were classified as having Lodwick classification IA, IB, and IC, respectively. Allogeneic and autogenous bone grafting was used in 13 and four patients, respectively. All patients had good bone healing and no local recurrence was observed. One patient developed osteonecrosis of the femoral head (Steinberg IA) and one developed secondary osteoarthritis of the hip joint (Kellgren-Lawrence Grade II). The mean postoperative MSTS functional score was 27.7 (24 to 30). Surgical dislocation and modified trapdoor procedures are safe and effective techniques for treating chondroblastoma in the femoral head. Cite this article: Bone Joint J 2019;101-B:732-738.

Have the difficulties and complications of surgical treatment for chondroblastoma of the adjoining knee joint been overestimated?

Background and objectiveChondroblastoma is difficult to treat as the tumor is surrounded by both articular cartilage and the epiphyseal plate. The differences in joint shape further complicate the problem. This retrospective study evaluates the efficacy of intraregional aggressive curettage and allogeneic bone grafting for treating chondroblastoma of the adjoining knee joint. MethodsFrom February 2010 to February 2017, 36 patients with chondroblastoma of the adjoining knee joint were identified. All patients were treated with intraregional aggressive curettage, phenolization, and allogeneic bone grafting. Follow-up for lesion healing, local recurrence, functional outcomes and secondary osteoarthritis were assessed both clinically and radiologically. ResultsThirty-six patients (mean age 17 years) were enrolled with a mean follow-up of 51.8 months (18–98 months). The tumor locations were as follows: distal femur (14), proximal tibia (20), and patella (2). Only 1 patient relapsed, 10 months post-operation. All patients had good bone healing. No knee varus or valgus deformity developed. The mean Musculoskeletal Tumor Society functional score was 28.6 ± 1.1 post-operation. At the last follow-up, secondary osteoarthritis was found in 1 patient, the patient was asymptomatic. ConclusionsIntraregional aggressive curettage, phenolization, and allogeneic bone grafting are effective for treatment of chondroblastoma of the adjoining knee joint.

Minimum 5-Year Follow-Up Outcomes for Comparison Between Titanium Mesh Cage and Allogeneic Bone Graft to Reconstruct Anterior Column Through Posterior Approach for the Surgical treatment of Thoracolumbar Spinal Tuberculosis with Kyphosis

We aimed to compare the clinical efficacy of titanium mesh cage with that of allogeneic bone graft to reconstruct the anterior column through posterior approach for the surgical management of patients with thoracolumbar spinal tuberculosis with kyphosis. From January 2011 to March 2013, 57 patients with single-segment or two-segments thoracolumbar spinal tuberculosis with kyphosis were treated by debridement, interbody graft, posterior instrumentation, and fusion via a posterior-only procedure. Twenty-four patients in group A were treated with allogeneic bone graft to reconstruct the anterior column, whereas 33 patients in group B were treated with titanium mesh cage. The clinical efficacy was evaluated by visual analog scale (VAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), neurologic function recovery, kyphotic Cobb angle, and postoperative complications. The mean follow-up was 72.4 months. Neurologic function was significantly improved after surgery in all cases. There were significant differences of VAS, ESR, and CRP between preoperation and postoperation at the final follow-up, with no significant difference between the two groups. The kyphotic Cobb correction was significantly improved when compared with those in preoperation, but there was no significant difference between the two groups. One patient in group A with two segments involved experienced graft fracture. He had anterior bone graft with titanium mesh cage. Minimum 5-year follow-up outcomes showed that one-stage posterior focus debridement, interbody graft using titanium mesh cages, posterior instrumentation, and fusion is an effective treatment for patients with thoracolumbar spinal tuberculosis accompanied by kyphosis. It may obtain better clinical efficacy than allogeneic bone graft for treating two-segments thoracolumbar spinal tuberculosis.

Augmentation of plate osteosynthesis for proximal humeral fractures: a systematic review of current biomechanical and clinical studies.

Secondary dislocation due to loss of fixation is the most common complication after plate fixation of proximal humeral fractures. A wide range of different techniques for augmentation has been described to improve the primary and secondary stability. Nevertheless, comparative analyses on the specific advantages and limitations are missing. Therefore, the aim of the present article was to systematically review and evaluate the current biomechanical and clinical studies. The databases of PubMed and EMBASE were comprehensively searched for studies on augmentation techniques for proximal humeral fractures using defined search terms. Subsequently, all articles identified were screened for eligibility and subdivided in either clinical or biomechanical studies. Furthermore, the level of evidence and study quality were assessed according the Oxford Centre for Evidence-Based Medicine and the Coleman Methodology Score, respectively. Out of 2788, 15 biomechanical and 30 clinical studies were included. The most common techniques were structural allogenic or autologous bone grafting to enhance the medial support, metaphyseal void filling utilizing synthetic bone substitutes or bone grafts, and screw-tip augmentation with bone cement. Biomechanical data were available for structural bone grafting to enhance the medial support, void filling with synthetic bone substitutes, as well as for screw-tip augmentation. Clinical evidence ranged from level II-IV and study quality was 26-70/100 points. Only one clinical study was found investigating screw-tip augmentation. All studies included revealed that any kind of augmentation positively enhances mechanical stability, reduces the rate of secondary dislocation, and improves patients' clinical outcome. None of the studies showed relevant augmentation-associated complication rates. Augmentation of plate fixation for proximal humeral fractures seems to be a reliable and safe procedure. All common techniques mechanically increase the constructs' stability. Clinically evaluated procedures show reduced complication rates and improved patient outcomes. Augmentation techniques seem to have the highest significance in situations of reduced bone mineral density and in high-risk fractures, such as 4-part fractures. However, more high-quality and comparative clinical trials are needed to give evidence-based treatment recommendations.

Characterization of circulating DNA in plasma of patients after allogeneic bone grafting

ObjectivesCell-free DNA (cfDNA) harboring mutations has been found in patients with diseases. Experimental studies have shown that cfDNA can be transmitted, leading to transformations in the host. In the present study, we evaluated whether bone allograft material contains cfDNA and whether this foreign cfDNA can be released into the patient’s blood circulation.Materials and methodsPlasma samples were collected preoperatively and postoperatively on the same day, at 5 weeks, and 4 months from 25 women who received bone allograft material (test group) from male donors and from 10 women who were treated with autologous graft (control group, only pre- and postoperative samples were collected). DNA was quantified and characterized in bone material and plasma samples by quantitative PCR with primers specific for glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and Y chromosome and gel electrophoresis. DNA in bone material was digested by different concentrations of DNase I.ResultsWe detected between 1 and 1.8 μg cfDNA fragments at a length around 601 base pairs (bp) and smaller in each 100 mg allograft. Treatment of the allograft with DNase I completely degraded the longer but not the shorter DNA 90-bp fragments. Y-DNA was not detected in the patients’ bloodstream at any time during the treatment and follow-up, but elevated levels of circulating cfDNA could be measured immediately postoperatively.ConclusionsOur results suggest that a transmission of DNA from allografts used for alveolar ridge reconstruction in humans is unlikely. The observed increase in circulating cfDNA in allograft and autograft patients immediately postoperatively may be elicited by the surgical procedure.Clinical relevanceThe results support the safety of allograft materials. The results suggest that human allograft materials seem not to release DNA into the blood since we did not measure Y-DNA with our technique.

Periprosthetic humeral fractures: from osteosynthesis to prosthetic replacement

Stabilization of the humeral shaft and the restoration of shoulder function dependent on the osseous integrity of the prosthetic stem component. In cases of astable prosthesis stem, an isolated plate osteosynthesis is possible. Prosthesis stem replacement is indicated in cases of aloose stem. With sufficient bone stock of the proximal humeral segment, achange to ashorter humeral shaft component with subsequent plate fixation of the fracture is possible. If the bone stock is poor, conversion to along revision stem is necessary. Inoperability of the patient due to serious comorbidities. Advanced age and low demands on shoulder function are relative contraindications for complex prosthesis replacements. Plate osteosynthesis can be done through an anterior or posterior approach, stem replacement only from anterior deltopectoral approach. When changing humeral shaft components, the loose shaft and all cement residues are removed, the fracture is reduced and, if possible, ashorter shaft is implanted with subsequent plate osteosynthesis of the fracture. When changing to along revision stem, additional osteosynthesis with cerclages wires is usually sufficient. In case of poor bone stock, an additive autologous or allogenic bone grafting can be performed. An instable anatomical prosthesis with poor shoulder function may require conversion to an inverse prosthesis. In cases of an isolated plate osteosynthesis with an otherwise stable prosthesis, immediate active rehabilitation of the upper limb is advocated. When aprosthesis replacement and conversion to an inverse prosthesis is performed the shoulder is immobilized in 30°abduction for 6weeks. Passive and after 3weeks active-assistive shoulder movement up to 90°abduction and flexion is allowed. In 40patients with aperiprosthetic humeral fracture, an isolated plate osteosynthesis was performed in 30cases and aprosthesis replacement in 10cases. Complications included 3infections and 3temporary radial nerve palsies. Revisions due to pseudarthrosis were necessary in 2cases.

Bone Defects in Revision Total Knee Arthroplasty and Management.

This article reviews the recent updates in revision of total knee arthroplasty (RTKA). We reviewed the recent articles on RTKA in databases including PubMed, Google Scholar, and SCOPUS. Total knee arthroplasty (TKA) involves the replacement of all three compartments of the knee in surgery of the knee joint to restore capacity and function. TKA is one of the most common and reliable surgical treatment options for the treatment of knee diseases. However, some patients require revision of TKA (RTKA) after primary TKA for various reasons, including mechanical wear, implant loosening or breakage, malalignment, infection, instability, periprosthetic fracture, and persistent stiffness. Unfortunately, the overall outcome of RTKA is not as satisfactory as for primary TKA due to the uncertainty regarding the actual success rate and the risk factors for failure. Cementation, modular metal augmentation, bone grafting, autologous bone grafting, allogenic bone grafting, impactation bone grafting, structural bone allografting, metaphyseal fixation, using porous titanium coated press fit metaphyseal sleeves and porous tantalum structural cones, and megaprostheses or customized prostheses are the currently available management options for RTKA. However, most of the management systems possess specific complications. Novel approaches should be developed to improve functional capacity, implant survival rates, and quality of life in a cost‐efficient manner.

Platelet Rich Fibrin for the Treatment of Cleft like Gingival Recession: A Case Report

Background: Gingival recession exposes the tooth’s root with aesthetic disfigurement, frequently brings a patient to a dentist’s office for the objectionable aesthetics caused by the disease. This case report addressed the management of localized cleft like gingival recession in the tooth no 31 with the aid of Platelet Rich Fibrin (PRF).
 Methods: Mucosal flap was retracted from tooth no 41 to 33 followed by curettage and root planning on the effected tooth (where there was gingival recession). Allogenic bone graft was applied over the affected area, covered with freshly prepared autogenous PRF membrane, flap was repositioned and sutured.
 Results: Within six month after surgery previously denuded root surface of the treated incisor became entirely covered with mucosa and good aesthetics was regained; which after 4 years, maintained stable gingival contour and aesthetics.
 Conclusion: The result in the presented case indicate that PRF can be applied when cleft like gingival recession due to malocclusion is necessarily to be treated uneventfully with good aesthetics.
 Bangladesh Med Res Counc Bull 2018; 44: 168-170

Technology of manufacturing of personalized reconstructive allogenic bone graft (in Russian only)

To develop the technology of manufacturing of reconstructive allogenic bone graft with individual parameters by using of digital prototyping and modeling. Allogeneic cadaveric bone blocks were used as material. The following methods were used to develop a manufacturing technology for personalized allogenic reconstructive bone implant: harvesting and special preparation of cadaveric material, primary disinfection, viral inactivation, ultrasound management, lyophilization of bone material, CT-examination of patients with various bone defects, digital prototyping and modeling, milling on a machine with numerical program control, X-ray sterilization. The technology of manufacturing of reconstructive allogenic bone graft with individual parameters was successfully tested in the treatment of 24 patients with post-traumatic, destructive-dystrophic and degenerative defects of jaws in 2012-2015. Final reconstructive allogenic bone implant has a personalized 3D-geometry in accordance with individual maxillofacial anatomy of particular patient. One of implant surfaces is fully congruent to the jaw bone defect, the others form the width, height and volume of reconstructive bone implant considering personified maxillofacial features. All above-mentioned features of bone implant are important to restore chewing function of dental system. The problem of bone implant personification may be resolved by using of computed tomography followed by digital analysis of jaw structure, technologies for digital reconstruction of bone defects (digital prototyping and modeling) and digital manufacturing.