Xenogenic Bone Graft Research Articles

Long-term rabbits bone response to titanium implants in the presence of inorganic bovine-derived graft

This study evaluated bone responses to titanium implants in the presence of an inorganic graft material. The bilateral mandible incisors of 24 rabbits were surgically extracted and one of the exposed sockets, chosen at random, was filled with an inorganic xenogenic bone graft (Gen-ox®), whereas the remaining socket was left to heal naturally and served as a control. After 60 days, titanium implants were inserted in the specific areas, and on days 0, 30, 60, and 180 after the implant insertions, six animals of each group were killed. Digital periapical radiography of implant region was obtained and vertical bone height (VBH) and bone density (BD) were evaluated by digital analysis system. In the undecalcified tissue cuts, bone-to-implant contact (BIC) and bone area (BA) within the limits of the implant threads were evaluated and compared statistically by means of two-way ANOVA and Tukey's test (ρ < 0.05). No significant differences were detected in VBH and BA, either between groups or between different experimental intervals. The BD was significantly higher in the experimental group than in the control group in all the intervals tested, but there were no significant differences by interval. The BIC was statistically lower in the control group on day 0; however, a significant increase was observed on days 60 and 180 (ρ < 0.05). The use of an inorganic xenograft prior to insertion of a titanium implant did not interfere with the course of osseointegration.

Treatment of through-and-through bone lesion using autologous growth factors and xenogeneic bone graft: a case report

This pilot case study aimed at evaluating the possibility of achieving optimal hard and soft tissue regeneration using plasma rich in growth factors (PRGF) and anorganic bovine bone (ABB) for the surgical treatment of a large through-and-through periapical bone lesion. Maxillary incisors of a patient with through-and-through periapical lesion of endodontic origin were treated using modern endodontic surgical technique with the adjunct of PRGF. The PRGF clot was positioned over the palatal side of the lesion while the remaining bone defect was grafted with PRGF and ABB. A collagen membrane embedded with plasma very rich in growth factors covered the graft. Post-operative pain and swelling were negligible, and soft tissue healing was very fast. One-year clinical and radiographic outcome showed complete healing and functionality. The addition of PRGF to ABB could improve the regenerative process, reducing postoperative symptoms and resulting in a fast and predictable hard and soft tissue healing.

Bone graft materials and its intended use

bone grafting is indicated in the case of bony defects and is classified into autograft, allograft, and xenograft. Synthetic bone graft is contrasted with these three categories in that it has a different donor source. Autograft is most prominent as it is known as a gold standard of all grafting procedures. Its principles and practices are well established via accumulated informations and clinical experiences, which imposes no regulations or restrictions in its clinical use. On the other hand, other bone graft procedures are under tight control for the safety and effectiveness of each product. Food and Drug Administration of the United States has a system in which the information on the approvals and clearances of bone graft materials on their internet homepage. All the bone graft materials that are under the regulations of the United States are classified into the category of medical devices, which includes allogenic bone, xenogenic bone, and synthetic bone graft materials. Each bone graft material has its own indication and the FDA approvals and clearances of medical devices contain the item of "intended use" to specify the indications of each bone graft materials. US dentists, as users of the specific bone graft materials, are provided with adequate information on the approved materials they are to utilize. As an user of these materials, Korean dentists are less provided with the information on the bone graft materials they want to use. Medical providers of the bone graft materials have to be able to provide their users with the essential information such as the intended use of the regulatory approval. Dentists must also be active in gathering informations on the material of their interest, and the system must be built in which both of the medical providers and users of bone graft materials can be satisfied in providing and getting the information, respectively.

Clinical evaluation of regenerative potential of type I collagen membrane along with xenogenic bone graft in the treatment of periodontal intrabony defects assessed with surgical re-entry and radiographic linear and densitometric analysis.

Background and Objectives:The primary goal of periodontal therapy is to restore the tooth supporting tissues lost due to periodontal disease. The aim of the present study was to compare the efficacy of combination of type I collagen (GTR membrane) and xenogenic bone graft with open flap debridement (OFD) in treatment of periodontal intrabony defects.Materials and Methods:Twenty paired intrabony defects were surgically treated using split mouth design. The defects were randomly assigned to treatment with OFD + collagen membrane + bone graft (Test) or OFD alone (Control). The clinical efficacy of two treatment modalities was evaluated at 9 month postoperatively by clinical, radiographical, and intrasurgical (re-entry) parameters. The measurements included probing pocket depth (PD), clinical attachment level (CAL), gingival recession (GR), bone fill (BF), bone density (BD) and intra bony component (INTRA).Results:The mean reduction in PD at 0–9 month was 3.3±0.82 mm and CAL gain of 3.40±1.51 mm occurred in the collagen membrane + bone graft (Test) group; corresponding values for OFD (Control) were 2.20±0.63 mm and 1.90±0.57 mm. Similar pattern of improvement was observed when radiographical and intra-surgical (re-entry) post operative evaluation was made. All improvement in different parameters was statistically significant (P< 0.01).Interpretation and Conclusion:Treatment with a combination of collagen membrane and bone graft led to a significantly more favorable clinical outcome in intrabony defects as compared to OFD alone.

Osteoblast differentiation of human bone marrow stromal cells (hBMSC) according to age for bone tissue engineering

Tissue engineered bone (TEB) can replace an autogenous bone graft requiring an secondary operation site as well as avoid complications like inflammation or infection from xenogenic or synthetic bone graft. Adult mesenchymal stem cells (MSC) for TEB are considered to have various ranges of differentiation capacity or multipotency by the donor site and age. This study examined the effect of age on proliferation capacity, differentiation capacity and bone morphogenetic protein-2 (BMP-2) responsiveness of human bone marrow stromal cells (hBMSC) according to the age. In addition, to evaluate the effect on enhancement for osteoblast differentiation, the hBMSC were treated with Trichostatin A (TSA) and 5-Azacitidine (5-AZC) which was HDAC inhibitors and methyltransferase inhibitors respectively affecting chromatin remodeling temporarily and reversibly. The young and old group of hBMSC obtained from the iliac crest from total 9 healthy patients, showed similar proliferation capacity. Cell surface markers such as CD34, CD45, CD90 and CD105 showed uniform expression regardless of age. However, the young group showed more prominent transdifferentiation capacity with adipogenic differentiation. The osteoblast differentiation capacity or BMP responsiveness was low and similar between young and old group. TSA and 5-AZC showed potential for enhancing the BMP effect on osteoblast differentiation by increasing the expression level of osteogenic master gene, such as DLX5, ALP. More study will be needed to determine the positive effect of the reversible function of HDAC inhibitors or methyltransferase inhibitors on enhancing the low osteoblast differentiation capacity of hBMSC.

M644: Clinical Applications of Recombinant Human Bone Morphogenetic Protein-2 (rhBMP-2)

Human Bone Morphogenetic Proteins (BMP) are a group of bone inductive proteins that determine and form the human skeleton. In the adult, they reform bone after osteoclastic resorption as part of the normal bone turnover cycle. The concentration of BMP in human and animal bone is exceedingly small negating its clinical usefulness for bone induction via xenogenic or allogenic bone grafts. However, molecular biotechnology has cloned the BMP-2 genes to produce clinically effective concentrations in a recombinant form.

A clinical and radiological evaluation of DFDBA with amniotic membrane versus bovine derived xenograft with amniotic membrane in human periodontal grade II furcation defects

The purpose of the present study was to clinically and radiographically evaluate and compare the efficacy of demineralized freeze dried bone allograft (DFDBA) and bovine derived xenogenic bone graft (BDX) [Bio-Oss] with amniotic membrane (AM) as guided tissue regeneration (GTR) in the treatment of human periodontal Grade II buccal furcation defects. Ten patients suffering from chronic periodontitis, displaying bilateral Grade II buccal furcation defect, were randomly treated using DFDBA with AM (Experimental site A) or using bovine derived xenograft (BDX) with AM (Experimental site B). The clinical and radiographic parameters were recorded at baseline, 6 and 9 months. Healing was uneventful in all patients except one site which was treated with BDX + AM. At 9 months after therapy, soft tissue measurements for the DFDBA + AM group showed pocket depth (PD) reduction of 4.7 mm +/- 0.58, and relative attachment level gain of 4.8 mm + 0.32, while the BDX + AM group showed a PD reduction of 4.4 mm +/- 0.27, and AL gain of 5.1 mm +/- 0.09. Osseous measurements showed bone fill of 2.1 mm +/- 0.36 for the DFDBA + AM group and 2.43 mm +/- 0.38 for the BDX + AM group. Percentage gain in bone was 76.3% for the DFDBA + AM group and 79.6% for the BDX + AM group. Statistical analysis revealed there was no statistical difference between the two materials in all measurements. Within the limits of the present study, it can be concluded that: (1) at 9 months after surgery both therapies resulted in significant PD reductions and CAL gains and (2) significant improvement was seen in bone fill and percentage gain with both the material, however, there was no significant difference between both.

Effect of combined therapeutical methods on healing of intrabony defects in regenerative periodontal surgery

Several methods are available to enhance the healing and regeneration of periodontal tissues after surgical therapy of intrabony defects. The main indications for the use of combined regenerative procedures are the extent and morphology of the osseous lesions. The six studies of the present dissertation focused on the clinical effect of different barrier techniques, bone substitutes, enamel matrix derivatives and a growth factors containing adjuvant used in various combinations on the healing of severe periodontal intrabony impairments. Synthetic, xenogenetic and autologous materials were used in these randomized clinical studies. Mechanical barriers (polytetrafluoroethylene and collagen membranes) for GTR, biological barriers/enamel matrix proteins (EMD), synthetic (β-TCP) and xenogeneic (NBM) bone grafts and autologous platelet-rich plasma (PRP) were combined in the test and control groups of the trials. The main clinical variable was the clinical attachment level (CAL) and the subsidiary one was the probing pocket depth (PPD), estimated at baseline and after one year. The summation of the results after the statistical analysis takes cognizance of the followings: a) Each of the eleven regenerative methods evaluated (ten combined procedures) leads to significant CAL gain and PPD decrease. b) Using β-TCP or NBM with EMD or with PRP + GTR and GTR’s, the difference between the parameters of the test and control groups were not statistically significant. c) It was confirmed in four studies that the addition of PRP to graft materials has not increased significantly the positive outcomes independent of the type of barrier or graft. d) Adding platelet-rich plasma to natural bone mineral, no benefit was observed from the point of view of the clinical variables. e) The polypeptide proteins of the platelet-rich plasma do not enhance the clinical regenerative effect of enamel matrix proteins. In conclusion, the option of the periodontal surgeons between these methods depends mainly on the defect morphology, the patient’s approach to the different types of materials, the medical concept of the physician, the technical possibilities and the clinical experience of the periodontist.

Immediate implants placed into infected sockets: a case report with 3-year follow-up

The esthetics and functional integrity of the periodontal tissue may be compromised by dental loss. Immediate implants became a viable option to maintain the periodontal architecture because of their anatomic compatibility with the dental socket and the possibility of eliminating local contamination. This article describes the procedure of immediate implant placement in the anterior maxilla replacing teeth with chronic periapical lesions, which were condemned due to endodontic lesions persisting after failed endodontic treatment and endodontic surgery, and discusses the relationship between the procedure and periapical lesions. Surgical removal of hopeless teeth 11, 12 and 21 was performed conservatively in such a way to preserve the anatomy and gingival esthetics. A second surgical access was gained at the apical level, allowing the debridement of the surgical chamber for elimination of the periapical lesion, visual orientation for setting of the implants and filling of the surgical chamber with xenogenous bovine bone graft. After this procedure, the bone chamber was covered with an absorbent membrane and the healing screws were positioned on the implants. Later, a provisional partial removable denture was installed and the implants were inserted after 6 months. After 3 years of rehabilitation, the implants present satisfactory functional and esthetic conditions, suggesting that immediate implant placement combined with guided bone regeneration may be indicated for replacing teeth lost due to chronic periapical lesions with endodontic failure history in the anterior maxilla.

Bone grafts cultured with bone marrow stromal cells for the repair of critical bone defects: An experimental study in mice

Tissue engineering of autologous bone combined with osteoprogenitor cells is a suitable strategy for filling large bone defects. The aim of this study was to evaluate the osteogenicity of a xenogenic bone graft cultured with allogenic bone marrow stromal cells (BMSC) in a mouse critical size craniotomy. Bovine trabecular bone grafts were made free of bone marrow cells or debris and were delipidated. BMSC were harvested from C57BL/6-Tg(ACTbEGFP)1Osb/J mice (GFP+ cells) and were cultured 14 days on bone grafts in control or osteogenic medium. Engineered grafts were implanted in calvarial defect in C57BL/6 mice. Four groups were studied: graft with BMSC differentiated in osteoblasts (G-Ob), graft with BMSC (G-BMSC), graft without cells (G) and no graft. Calvariae were studied 2 and 8 weeks after implantation by radiographic and histomorphometric analyses. G group: the bone ingrowth was limited to the edges of the defect. The center of the graft was filled by a fibrovascular connective tissue. G-BMSC or G-Ob groups: bone formation occurred early in the center of the defect and did not increase between 2 and 8 weeks; the newly formed woven bone was partially replaced by lamellar bone. The preoperative osteoblastic differentiation of BMSC did not allow faster and better bone regeneration. After 2 weeks, GFP+ cells were observed around the grafted bone but no GFP+ osteocyte was present in the newly formed bone. No GFP+ cell was noted after 8 weeks. However, pre-implantation culture of the biomaterial with allogenic BMSC greatly enhanced the bone regeneration.

Radiographic assessment of impacted mandibular third molar sockets filled with composite xenogenic bone graft

The main purpose of this study was to evaluate the radiographic aspect of the healing of extraction sockets filled with a xenogenic graft material (Gent-tech). Thirty-nine patients ranging in age from 15 years to 25 years with bilateral impacted mandibular molars were chosen based on bilateral mandibular similarities. After tooth extraction, the socket was filled with the graft. The opposite site was left to heal naturally and served as a control. The experimental and control sites were chosen randomly. Bone density and crest healing were evaluated on digital radiographs taken immediately, 2 months and 6 months after surgery. The respective pixels values obtained with the Digora software were compared statistically. The results showed a significant decrease in the distance from the cemento-enamel junction to the alveolar bone crest, but no difference was found between the control and experimental groups. Bone density increased significantly, and there was difference between experimental and control groups. The analysed parameters observed by the authors were similar to those of the control group, suggesting xenogenic graft being an acceptable material and a graft option.

M632: Clinical Applications of Recombinant Bone Morphogenetic Protein-2 (rhBMP-2)

Human Bone Morphogenetic Proteins (BMP) are a group of bone inductive proteins that determine and form the human skeleton. In the adult, they reform bone after osteoclastic resorption as part of the normal bone turnover cycle. The concentration of BMP in human and animal bone is exceedingly small negating its clinical usefulness for bone induction via xenogenic or allogenic bone grafts. However, molecular biotechnology has cloned the BMP-2 genes to produce clinically effective concentrations in a recombinant form.

Distribution of Cortical Bone in Bovine Limbs

Xenogenic bone grafts have been widely researched because they are not limited in terms of volume and size like autogenous and allogenic grafts, and the favored bone for xenografts is bovine bone. However, the efficacy of cortical bone from bovine limb for xenografts is not clearly known. In this study, the distribution of cortical bone in bovine humerus, radius, femur, and tibia were investigated. Each experimental bone was split longitudinally with a bone saw and bone marrow and cancellous bone were removed. The thicknesses of cortical layers in sample diaphyses were measured at 1cm intervals using a micrometer. The mean lengths of cortical portions were; humerus 14.7 +/- 2.3 cm, radius 19.0 +/- 2.6 cm, femur 19.0 +/- 3.2 cm, and tibia 23.0 +/- 3.1 cm. Thickest cortical bone was found at the distal caudal metaphysis of the humerus, the proximal caudal metaphysis of the radius, the craniolateral and caudomedial midshaft of the femur and the lateral and medial midshaft of tibia. The mean surface areas of cortical bone were humerus 187.4 +/- 15.44 cm2, radius 229.2 +/- 43.31 cm2, femur 295.8 +/- 8.93 cm2, and tibia 290.0 +/- 30.44 cm2. And, mean volumes of cortical bone were humerus 149.42 +/- 15.35 cm3, radius 166.26 +/- 20.02 cm3, in femur 220.45 +/- 22.73 cm3, and tibia 214.89 +/- 20.05 cm3. The results of this study can be used to produce cortical bone-based plates and screws.

Regenerative Potential of Platelet‐Rich Plasma Added to Xenogenic Bone Grafts in Peri‐Implant Defects: A Histomorphometric Analysis in Dogs

The purpose of this investigation was to evaluate the regenerative influence of platelet-rich plasma (PRP) added to xenogenic bone grafts on bone histomorphometric parameters in a dog model. Ninety endosseous dental implants were inserted in the mandibles of nine hound dogs. Mesial and distal 3-wall peri-implant defects were surgically created adjacent to the implants. Defects were randomly assigned to three groups: demineralized freeze dried bone with platelet-rich plasma (DFDB + PRP), DFDB alone, and no treatment (NT). Animals were sacrificed at 1, 2, and 3 months according to a previously established randomization schedule, and specimens were subjected to histomorphometric analysis. Percentages of bone area inside the implant threads (BiIT), bone-to-implant contact (BIC), and bone area outside implant threads (BoIT) were recorded. Treatment effects were evaluated using analysis of variance models. The effect of the three treatments on the outcome measures did not differ significantly by healing time (P > 0.05 for the healing time by treatment interaction). However, the average (standard deviation) percentage of BIC and BoIT was significantly different between the treatment groups. In particular, the average percentage of BIC differed between peri-implant defects treated with DFDB + PRP (33.8% [11.0]) and those treated with DFDB alone (28.5% [10.8]; P = 0.042), as well as those in the NT group (27.9% [11.0]; P = 0.024). Furthermore, the average percentage of BoIT differed significantly between defects treated with DFDB + PRP compared to defects in the NT group (51.6% [12.2] versus 43.3% [10.3]; P = 0.005). There was borderline evidence to suggest that the average percentage of BiIT and BIC was significantly different depending on the length of the healing time (P = 0.054 and P = 0.085, respectively). This study found that the addition of PRP to xenogenic bone grafts demonstrated a low regenerative potential in this animal model.

Influence of Platelet‐Rich Plasma Added to Xenogeneic Bone Grafts in Periimplant Defects: A Vital Fluorescence Study in Dogs

The use of platelet-rich plasma (PRP) has been suggested in order to increase the rate of bone deposition when sites are augmented prior to or in conjunction with dental implant placement. The goal of this study was to investigate whether the addition of PRP to xenogeneic bone grafts would increase the rate of bone formation in dogs. Ninety endosseous dental implants were inserted in the mandibles of nine hound dogs. Subsequently, mesial and distal three-wall periimplant defects were surgically created. Defects were randomly assigned to three groups: demineralized freeze-dried bone graft plus platelet-rich plasma (DFDBG plus PRP), demineralized freeze-dried bone graft alone (DFDBG), and no treatment. Postsurgically each dog received a series of three fluorescent labels for estimation of bone cell activity at baseline and during different stages of healing, with particular attention to the bone formation rate per tissue volume (BFR/TV). Animals were sacrificed at 1 month, 2 months, and 3 months, and specimens were subjected to analysis by fluorescence microscopy. Treatment effects were evaluated with analysis of variance models. Overall, the average BFR/TV differed by treatment although this difference approached only minimal statistical significance (p = .057). The largest difference occurred between periimplant defects treated with DFDBG only and defects that were not treated (mean percentage BFR/TV, 0.0720% vs 0.0994%). There was no evidence of an overall treatment effect (p = .27) for the mineral apposition rate (MAR) values. The data also suggest a consistent variability in the bone formation parameters among the three groups at different healing points. In this animal model the addition of PRP to xenogeneic bone grafts did not demonstrate evidence of faster bone formation during healing. However, limitations of the histologic technique possibly played a negative role in the assessment of bone formation parameters.

A Comparative Study of the effects of Autogenous and Xenogenic Bone grafts with PRP(Platelet Rich Plasma) technique on Periodontal Regeneration

A Comparative Study of the effects of Autogenous and Xenogenic Bone grafts with PRP(Platelet Rich Plasma) technique on Periodontal Regeneration

The efficacy of bone replacement grafts in the treatment of periodontal osseous defects. A systematic review.

Bone replacement grafts (BRG) are widely used in the treatment of periodontal osseous defects; however, the clinical benefits of this therapeutic practice require further clarification through a systematic review of randomized controlled studies. The purpose of this systematic review is to access the efficacy of bone replacement grafts in proving demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone. What is the effect of bone replacement grafts compared to other interventions on clinical, radiographic, adverse, and patient-centered outcomes in patients with periodontal osseous defects? The computerized bibliographical databases MEDLINE and EMBASE were searched from 1966 and 1974, respectively, to October 2002 for randomized controlled studies in which bone replacement grafts were compared to other surgical interventions in the treatment of periodontal osseous defects. The search strategy included screening of review articles and reference lists of retrieved articles as well as hand searches of selected journals. All searches were limited to human studies in English language publications. Non-randomized observational studies (e.g., case reports, case series), publications providing summary statistics without variance estimates or data to permit computation, and studies without BRG intervention alone were excluded. The therapeutic endpoints examined included changes in bone level, clinical attachment level, probing depth, gingival recession, and crestal resorption. For purposes of meta-analysis, change in bone level (bone fill) was used as the primary outcome measure, measured upon surgical re-entry or transgingival probing (sounding). 1. Forty-nine controlled studies met eligibility criteria and provided clinical outcome data on intrabony defects following grafting procedures. 2. Seventeen studies provided clinical outcome data on BRG materials for the treatment of furcation defects. 1. With respect to the treatment of intrabony defects, the results of meta-analysis supported the following conclusions: 1) bone grafts increase bone level, reduce crestal bone loss, increase clinical attachment level, and reduce probing depth compared to open flap debridement (OFD) procedures; 2) No differences in clinical outcome measures emerge between particulate bone allograft and calcium phosphate (hydroxyapatite) ceramic grafts; and 3) bone grafts in combination with barrier membranes increase clinical attachment level and reduce probing depth compared to graft alone. 2. With respect to the treatment of furcation defects, 15 controlled studies provided data on clinical outcomes. Insufficient studies of comparable design were available to submit data to meta-analysis. Nonetheless, outcome data from these studies generally indicated positive clinical benefits with the use of grafts in the treatment of Class II furcations. 3. With respect to histological outcome parameters, 2 randomized controlled studies provide evidence that demineralized freeze-dried bone allograft (DFDBA) supports the formation of a new attachment apparatus in intrabony defects, whereas OFD results in periodontal repair characterized primarily by the formation of a long junctional epithelial attachment. Multiple observational studies provide consistent histological evidence that autogenous and demineralized allogeneic bone grafts support the formation of new attachment. Limited data also suggest that xenogenic bone grafts can support the formation of a new attachment apparatus. In contrast, essentially all available data indicate that alloplastic grafts support periodontal repair rather than regeneration. 4. The results of this systematic review indicate that bone replacement grafts provide demonstrable clinical improvements in periodontal osseous defects compared to surgical debridement alone.

A Comparative Study of the effects of Synthetic and Xenogenic Bone grafts with PRP (Platelet Rich Plasma) technique on Periodontal Regeneration

A Comparative Study of the effects of Synthetic and Xenogenic Bone grafts with PRP (Platelet Rich Plasma) technique on Periodontal Regeneration

Brief history of the tissue bank, charles university hospital, hradec králové, czech republic.

A brief history of the Tissue Bank (TB) of the University Hospital Hradec Králové, Czech Republic, established by Dr. R. Klen in 1952 is presented. In Dr. Klen's original concept the TB was defined as a department specialised in the harvesting, processing, preservation, storage and distribution of various kinds of tissue for clinical and experimental practice. The first kinds of tissue collected in cadaveric donors were corneas, bone and skin. Xenogeneic cartilage and bone grafts were prepared at the same time. Later, preparation of soft connective tissues and chorion-amnion was introduced. During the first 15 years of activity a total of 11,443 grafts preserved by hypothermy at +4 degrees C or freezing in absence of cryoprotectants (-20 degrees C) were prepared. In the 60's freeze-drying of tissue grafts was introduced and the bank of cryopreserved cell lines was established. In the 80's cryopreservation of haematopoietic progenitor cells for clinical transplantations was started and the spectrum of tissue grafts was enlarged (xenogeneic pericardium and allogeneic specially treated dura mater for neurosurgical operations, pigskin for burn treatment, demineralised bone for parodontology and implantology). In the 90's human keratinocyte culture for treatment of burns and chronic skin defects was started. The human milk bank and organ bank co-operating with the Regional Transplantation Centre are component parts of the TB as well. The TB is an institutional member of the European Association of Tissue Banks and annually delivers approximately 1000 grafts that are used in University and county hospitals as well as in surgeons' private practices. Health insurance companies reimburse all grafts on a non-profit and tax-free basis.

Treatment outcome of osteofibrous dysplasia.

The disease course of six tibial lesions in five patients with osteofibrous dysplasia who were followed longer than 10 years (average: 16.8 years) was analyzed retrospectively. Three patients had a lesion of the unilateral tibia; one patient had lesions of the unilateral tibia and fibula; and one patient had lesions of the bilateral tibiae and ulnae. Curettage and autogeneic bone graft were performed on two lesions, which then healed. Of four lesions on which curettage and xenogeneic bone grafts were performed, three lesions healed, and one developed local recurrence. Curettage and xenogeneic bone graft were performed on the recurrent lesion, which finally healed and the deformity stopped. Three lesions healed without surgical treatment. During the long-term follow-up, this disease showed a clear tendency of healing. Surgical treatment should be considered in patients with disease uncontrollable by conservative treatment or those who have a high possibility of impending fracture and progressing deformity.