Bone graft substitutes currently available in orthopaedic practice: the evidence for their use.

We reviewed 59 bone graft substitutes marketed by 17 companies currently available for implantation in the United Kingdom, with the aim of assessing the peer-reviewed literature to facilitate informed decision-making regarding their use in clinical practice. After critical analysis of the literature, only 22 products (37%) had any clinical data. Norian SRS (Synthes), Vitoss (Orthovita), Cortoss (Orthovita) and Alpha-BSM (Etex) had Level I evidence. We question the need for so many different products, especially with limited published clinical evidence for their efficacy, and conclude that there is a considerable need for further prospective randomised trials to facilitate informed decision-making with regard to the use of current and future bone graft substitutes in clinical practice.

A prospective comparative study of radiological outcomes after instrumented posterolateral fusion mass using autologous local bone or a mixture of beta-tcp and autologous local bone in the same patient.

BACKGROUND: We previously reported a retrospective analysis of radiographic changes in instrumented posterolateral fusion mass (PLF) established using a mixture of local autologous bone and beta tricalcium phosphate (b-TCP) in lumbar spinal fusion surgery. Here, we report a prospective study to compare the use of local bone and a mixture of local bone and b-TCP in PLF in degenerative spinal surgery. METHODS: Radiological changes in the PLF mass in 42 patients were analyzed for 12 months. All patients had degenerative lumbar spinal disease and underwent instrumented fusion. Local autologous bone was used for PLF on the left side, and a mixture of local autologous bone and b-TCP was used for PLF on the right side. Lumbar spinal anterior-posterior (AP) images were performed immediately postoperative and at 1, 3, 6, and 12 months. Computed tomography (CT) was also done immediately postoperative and at 12 months. Fusion rate, radiodensity, and the dimensions of the PLF mass bilaterally on the AP X-ray were compared. The change in volume in both fusion bridges in the CT image was also compared. RESULTS: The overall fusion rates were 31/42 (73.8 %) and 24/42 (57.1 %) on the left and right sides, respectively. The decrease in radiodensity at 1 month postoperative was significantly greater on the left side than on the right side (from 0.79 to 0.74 versus from 0.81 to 0.78; p = 0.002). The mean immediate postoperative volume on the left side measured with CT was 5.1 cc (95 % CI, 4.94-5.34) and on the right side was 5.2 cc (95 % CI, 4.97-5.37). The mean volume at 12 months had decreased to 2.2 cc (95 % CI, 1.85-2.64) on the left side and 1.87 cc (95 % CI, 1.48-2.67) on the right side. The volume decrease on the right side was statistically greater than on the left side (p = 0.048). CONCLUSIONS: Based on the changes in radiodensity and fusion rate during follow-up, local bone seems to undergo earlier resorption and stabilization than the mixture of local bone and b-TCP..

Volume changes of autogenous bone after sinus lifting and grafting procedures: a 6-year computerized tomographic follow-up.

OBJECTIVES: To evaluate long-term bone remodelling of autografts over time (annually, for 6 years), comparing the block and particulate bone procedures for sinus floor elevation, as well as to evaluate the survival of positioned dental implants. PATIENTS AND METHODS: Twenty-three sinus lift procedures with autogenous bone were performed: seven sinus lift procedures using particulate graft and 10 with block autogenous bone were performed in 17 patients. Employing a software program, pre- and post-surgical computerized tomography (CT) scans were used to compare the volume (V) and density (D) of inlay grafts over time (up to 6 years), and to determine the percentage of remaining bone (%R). All variable (V, D and %R) measurements were then compared statistically. RESULTS: At the 6-year survey for block form, a resorption of 21.5% was seen, whereas for particulate grafts there was a resorption of 39.2%. Both groups exhibited bone remodelling between the first and second follow-up which was significant regarding volume for the block form and regarding density for the particulate group. CONCLUSIONS: During the initial period of healing, the cortico-cancellous block bone grafted into the maxillary sinus underwent a negative remodelling of the volume, which is most probably due to graft cortex resorption, coupled with, primarily, an increase in density in the spongious area; for the particulate grafts, significant augmentations in density were obtained. The lack of significant differences among volumes was due to the wide degree of dispersion of the data. The rough data presented in this paper seem to support the use of a bone-block grafting procedure in maxillary sinus augmentation.

Long-term follow-up of allograft reconstruction of segmental defects of the humeral head associated with posterior dislocation of the shoulder.

The purpose of this study is to report the long-term follow-up result of allograft reconstruction of segmental defect of the humeral head associated with posterior dislocation of the shoulder. Six men underwent operative management of defects of the humeral head involving 40% of the articular surface, following posterior dislocation of the humeral head. The period of time between dislocation and surgery ranged from 7 to 8 weeks. The defect in the head was filled with an allogeneic segment of humeral head contoured to restore the spherical shape. All the patients returned to their occupation 4 months later. All the cases were evaluated clinically and by radiographs and computed tomography (CT) scan at a mean of 122 (96-144) months after the operative procedure. Three men had no complaints of pain, instability, clicking or catching, whereas three had pain, clicking, catching and stiffness. The three patients with good clinical result showed also good radiographic result. The computed tomography (CT) confirmed incorporation of the allograft and no osteoarthrosis. Another patient had a good clinical and radiographic result until the eighth postoperative year. At 8-year follow-up examination, this patient developed shoulder osteoarthrosis and he had pain and stiffness. He needed an arthroplasty 10 years after the operation. The other two patients developed collapse of the graft and osteoarthrosis that were yet evident at 4-year follow-up. These patients required a shoulder arthroplasty 8 years after the procedure. We conclude that the treatment of segmental defects of the humeral head associated with posterior dislocations of the shoulder by allograft reconstruction has a good long-term follow-up result in 50% of the patients.

Use of an autogenous cortical graft in combination with guided tissue regeneration for treatment of an infrabony defect.

Infrabony periodontal defects are common findings encountered during complete oral examinations. Treatment options for infrabony lesions are aimed at meeting client demands as well as patient needs. Deciding on how to treat these lesions depends on the nature and degree of disease present as well as having the materials available to improve the chances of achieving the greatest clinical success. Bone grafting of an infrabony defect of the left mandibular first molar tooth of a dog using an autogenous cortical graft harvested with a reusable bone grafter in combination with guided tissue regeneration is described.

Volume changes of iliac crest autogenous bone grafts after vertical and horizontal alveolar ridge augmentation of atrophic maxillas and mandibles: a 6-year computerized tomographic follow-up.

PURPOSE: To evaluate by computerized tomography the long-term volume resorption of autogenous corticocancellous grafted bone harvested from the ilium and used in an alveolar augmentation procedure followed by endosseous dental implant placement. PATIENTS AND METHODS: Eleven maxillary grafts (8 positioned horizontally) and 13 mandibular grafts (10 positioned vertically) were placed in 16 patients. Using software programs, pre- and postsurgical computerized tomographic scans were used to compare volumes of grafts over time (up to 6 yr) to determine the annual percentage of remaining bone and the overall percentage of bone resorption that could be expected. Yearly measurements of volumes and percentages of remaining bone were then compared statistically. RESULTS: At the 6-year survey for blocks grafted in the mandible, an average resorption rate of 87% was obtained; for maxillary grafts at the same survey, complete resorption of the grafts (mean, 105.5%) was recorded. In general, bone resorption appeared slow, except for that recorded in the first 2 years of healing, the only period in which statistical comparisons among all time points showed significant differences for all variables. CONCLUSIONS: Volumetric measurements of the grafts and their related percentages of remaining bone attested to a progressive and unavoidable bone resorption of almost all the grafted bone in the maxilla and mandible. Although the present data were from a heterogeneous group of defects treated with horizontal and vertical procedures, clinicians, when performing alveolar bone augmentation with an autogenous hip bone, should aim at titanium dental implant osseointegration, not only in the augmented bone but also in the native bone below the graft.

Evaluation of alveolar bone grafting using limited cone beam computed tomography.

OBJECTIVE: The objective of this study was to evaluate the bone resorption of alveolar bone grafting using LCBCT scan. STUDY DESIGN: This was a prospective study. Nineteen patients with alveolar cleft were divided into 2 groups depending on the spontaneous eruption of the permanent tooth. All patients underwent alveolar bone grafting with iliac crest cancellous bone. LCBCT scans were taken 1 month and 6 months postoperatively. RESULTS: LCBCT scans obtained the length, width, and height of the bone grafts. Three-dimensional (3D) reconstruction of the bone grafts enabled a valuable objective assessment of the graft volume. The resorption ratio was 10.4% when the permanent tooth erupted spontaneously into the graft. In the group with absence of the permanent tooth, the resorption ratio was 36.6%. CONCLUSION: LCBCT scan and 3D reconstruction is a promising method for evaluation of the outcome of alveolar bone grafts. Bone grafts showed a high grade of resorption in patients lacking permanent tooth eruption.

Management of giant cell tumor of bone: computerized tomography based selection strategy and approaching the lesion through the site of cortical break.

OBJECTIVE: A retrospective study was carried out in patients with giant cell tumor of bone to compare the functional and radiographic outcome of curettage and bone grafting using a novel CT based selection strategy to that of patients of a similar age treated with anatomic/standard curettage and bone grafting. METHODS: Curettage and bone grafting after CT classification was performed in 31 patients and curettage and bone grafting without CT classification in 20. The surgical approach for curettage in the CT classified group of patients was through the site of the cortical break, irrespective of the standard approach to the particular region of bone involved. The aim of this approach was to achieve wide excision of the possibly involved soft tissue. RESULTS: At similar duration of follow up (72 months) in patients with a similar mean age (33 years), Musculoskeletal Tumor Society (MSTS) scores for CT classified patients were similar to those of patients who had undergone standard curettage. However, the postoperative recurrence rate in the CT classified group was significantly less (12.9%) than in the non-CT classified group. CONCLUSION: A CT based selection strategy is a valid preoperative tool for evaluation of giant cell tumor. Further, for curettage these lesions are better approached through the site of cortical break, irrespective of standard approaches, so that adequate soft tissue clearance can be achieved.

Platelet-rich plasma promotes angiogenesis of prefabricated vascularized bone graft.

PURPOSE: The objective was to assess the impact of platelet-rich plasma (PRP) on angiogenesis and bone formation of tissue-engineered bone in the prefabricated stage. MATERIALS AND METHODS: Both thighs of New Zealand white rabbits were used as prefabricated vascularized bone grafts using a combination of bone mesenchymal stem cells and vascular bundles in a titanium cage filled with ß-tricalcium phosphate ceramic. PRP was applied in the test group, and the same procedure was performed in the control group without the application of PRP. After 4, 8, and 12 weeks, delayed static bone scanning with technetium-99m methylene diphosphonate was performed before sacrifice, and the tissue-engineered bone samples were collected for immunohistochemical analysis using a monoclonal antibody against CD31 and histologic analysis. RESULTS: The results showed superior angiogenesis in the PRP group compared with the control group at each time point as determined by bone scintigraphy and immunohistochemical examinations. The results of histologic analysis also showed that there was more bone formation in the PRP group than in the control group at each time point. CONCLUSIONS: The application of autologous PRP was an effective strategy for increasing angiogenesis and bone formation in tissue-engineered bone and had potential significance for clinical applications.

Minimally invasive anterior transarticular screw fixation and microendoscopic bone graft for atlantoaxial instability.

PURPOSE: Even though transarticular screw (TAS) fixation has been commonly used for posterior C1-C2 arthrodesis in both traumatic and non-traumatic lesions, anterior TAS fixation C1-2 is a less invasive technique as compared with posterior TAS which produces significant soft tissue injury, and there were few reports on percutaneous anterior TAS fixation and microendoscopic bone graft for atlantoaxial instability. The goals of our study were to describe and evaluate a new technique for anterior TAS fixation of the atlantoaxial joints for traumatic atlantoaxial instability by analyzing radiographic and clinical outcomes. METHODS: This was a retrospective study of seven consecutive patients with C1-C2 instability due to upper cervical injury treated by a minimally invasive procedure from May 2007 to August 2009. Bilateral anterior TAS were inserted by the percutaneous approach under Iso-C3D fluoroscopic control. The atlantoaxial joint space was prepared for morselized autogenous bone graft under microendoscopy. The data for analysis included time after the injuries, operating time, intraoperative blood loss, X-ray exposure time, clinical results, and complications. Radiographic evaluation included the assessment of atlantoaxial fusion rate and placement of TAS. Bone fusion of the atlantoaxial joints was assessed by flexion extension lateral radiographs and 1-mm thin-slice computed tomography images as radiographic results. Clinical assessment was done by analyzing the recovery state of clinical presentation from the preoperative period to the last follow-up and by evaluating complications. RESULTS: A total of 14 screws were placed correctly. The atlantoaxial solid fusion without screw failure was confirmed by CT scan in seven cases after a mean follow-up of 27.5 months (range 18-45 months). All patients with associated clinical presentation made a recovery without neurologic sequelae. Postoperative dysphagia occurred and disappeared in two cases within 5 days after surgery. There were no other complications during the follow-up period. CONCLUSIONS: Percutaneous anterior TAS fixation and microendoscopic bone graft could be an option for achieving C1-C2 stabilization with several potential advantages such as less tissue trauma and better accuracy. Bilateral TAS fixation and morselized autograft affords effective fixation and solid fusion by a minimally invasive approach.

Volumetric difference evaluation of registered three-dimensional pre-operative and post-operative CT dental data.

OBJECTIVE: The purpose of this study is to propose a complete methodology for automatically registering three-dimensional (3D) pre-operative and post-operative CT scan dental volumes as well as to provide a toolset for quantifying and evaluating their volumetric differences. METHODS: The proposed methodology was applied to cone beam CT (CBCT) data from 20 patients in order to assess the volume of augmented bone in the alveolar region. In each case, the pre-operative and post-operative data were registered using a 3D affine-based scheme. The performance of the 3D registration algorithm was evaluated by measuring the average distance between the edges of the registered sets. The differences between the registered sets were assessed through 3D subtraction radiography. The volume of the differences was finally evaluated by defining regions of interest in each slice of the subtracted 3D data and by combining all respective slices to model the desired volume of interest. The effectiveness of the algorithm was verified by applying it to several reference standard-shaped objects with known volumes. RESULTS: Satisfactory alignment was achieved as a low average offset of 1.483 ± 1.558 mm was recorded between the edges of the registered sets. Moreover, the estimated volumes closely matched the volumes of the reference objects used for verification, as the recorded volume differences were less than 0.4 mm(3) in all cases. CONCLUSION: The proposed method allows for automatic registration of 3D CBCT data sets and the volumetric assessment of their differences in particular areas of interest. The proposed approach provides accurate volumetric measurements in three dimensions, requiring minimal user interaction.

Particulate vs. block bone grafts: three-dimensional changes in graft volume after reconstruction of the atrophic maxilla, a 2-year radiographic follow-up.

BACKGROUND: Extensive alveolar bone resorption in the maxilla limits the possibility of successful placement and osseointegration of endosseous implants for future prosthetic rehabilitation. Autogenous bone from the iliac crest may be used as lateral onlays in the atrophic maxilla, both as block and particulate bone. To our knowledge, there is no three-dimensional 2-year follow-up study measuring the volumetric reduction of the augmented areas comparing particulate and block bone grafts. PURPOSE: The aim of this study was to conduct a radiographic 2-year follow-up study, using computed tomographic (CT) images in order to evaluate and compare the extent of bone graft resorption in the frontal maxillae augmented by particulate (test) and block bone (control). MATERIAL AND METHODS: Eleven patients treated with iliac bone grafts and oral implants in the maxilla were followed with CT examinations directly post grafting and after 2 years. RESULT: The volumetric changes after 6 months were extensive. Additionally, the changes in particulate bone tended to be larger after 2 years compared to block bone, using this protocol. However, the difference was not statistically significant. CONCLUSION: The present follow-up study showed that there is radiographically complete integration and embedding of implants installed in grafted bone despite extensive initial graft resorption. There was no significant difference in the amount of volumetric reduction between particulate bone and block bone grafts.

Reliability of the Kindelan scoring system for alveolar bone grafting with and without a pre-graft occlusal radiograph in patients with cleft lip and palate.

We aimed to compare the reliability of the Kindelan system using one postoperative radiograph to assess the success of alveolar bone grafts with the use of two occlusal radiographs (before and after operation). This retrospective reliability study took place at Glasgow Dental Hospital cleft unit, and two examiners scored 84 radiographs two weeks apart. The sample was taken from a database of patients having alveolar bone grafts between 2007 and 2010. They had an upper anterior occlusal radiograph taken before the graft and another at a mean of 6 months (range 3-12 months) postoperatively. Kappa scores were used to measure intraobserver and interobserver agreement. Intraexaminer agreement ranged from good to very good using one or two radiographs, and interexaminer agreement ranged from moderate to good for both systems. Reliability when scoring with either one or two radiographs was similar, and ranged from good to very good.

Prototyped flexible grafting tray for reconstruction of mandibular defects.

In our previous studies, prototyped individual bone-grafting trays have been used to restore discontinuous mandibular defects. However, the attempts have shown that the trays have shielded the graft from stress, which caused considerable resorption of bone. To eliminate the shielding, we designed a flexible tray. Finite element analysis was used to compare the distribution of strain on the bone grafts that were placed in flexible and conventional trays. The analogue computation suggested that most of the strain on the graft in the flexible tray resulted in a beneficial mechanical environment, while in the conventional tray more than half of graft was in the lowest class of strain (disuse - <50 µstrains). Animal experiments were conducted on hybrid dogs, and the prototype flexible tray was used to carry particles of autologous cancellous iliac bone to reconstruct a 40 mm defect in the mandibular body. Sequential radionuclide bone imaging was used to monitor the bone metabolism. Animals were killed at 4, 12 and 24 weeks, and specimens processed for quantitative histological examination. The data from the flexible trays were compared with those from the conventional trays, as in our previous study. The results showed that bone metabolism was more active in the flexible tray than in the conventional tray during the early stages. There was increased bony adaptation in the flexible tray. These results indicate that the flexible tray can efficiently eliminate the shielding from stress, and allow more occlusive force to be conducted on to the bone graft, which results in better remodelling of the graft.

The maturation of grafted bone after posterior lumbar interbody fusion with an interbody carbon cage: a prospective five-year study.

We evaluated the maturation of grafted bone in cases of successful fusion after a one- or two-level posterior lumbar interbody fusion (PLIF) using interbody carbon cages. We carried out a five-year prospective longitudinal radiological evaluation of patients using plain radiographs and CT scans. One year after surgery, 117 patients with an early successful fusion were selected for inclusion in the study. Radiological evaluation of interbody bone fusion was graded on a 4-point scale. The mean grades of all radiological and CT assessments increased in the five years after surgery, and differences compared to the previous time interval were statistically significant for three or four years after surgery. Because the grafted bone continues to mature for three years after surgery, the success of a fusion should not be assessed until at least three years have elapsed. There were no significant differences in the longitudinal patterns of grafted bone maturity between iliac bone and local bone. However, iliac bone grafting may remodel faster than local bone.

The influence of perforating the autogenous block bone and the recipient bed in dogs. Part I: a radiographic analysis.

OBJECTIVES: This study evaluated radiographically the integration and volume maintenance of grafted autogenous block bone under various cortical bone perforation conditions in dogs. MATERIAL AND METHODS: Five mongrel dogs were used. Each dog received four differently prepared onlay block bone grafts: a solid block graft was fixed on either (1) a cortically perforated recipient bed (SGPR) or (2) a nonperforated recipient bed (SGNPR), a perforated block graft was fixed on either (3) a nonperforated recipient bed (PGNPR) or (4) a cortically perforated recipient bed (PGPR). The animals were sacrificed at 1 day, 4 days, 10 days, 4 weeks, and 8 weeks after surgery. Specimens were prepared and radiographic analysis was conducted by using micro-computed tomography. The residual bone volume (RBV; mm(3) ), cross-sectional bone area (BA; mm(2)), and residual height (RH; %) of the grafted block bone were measured radiographically. RESULTS: The interface between the recipient bed and the graft showed no signs of bone integration at 1, 4, and 10 days of healing. However, at 4 weeks of healing, bone integration was observed in all groups. The RBV, BA, and RH of the grafts gradually decreased by 4 weeks of healing. At 8 weeks, the PGPR condition exhibited a higher RBV, BA, and RH than the other conditions, whereas the SGNPR condition exhibited the lowest RBV, BA, and RH. CONCLUSION: Within the limitations of this study, it can be concluded that intentional cortical perforation on the recipient bed and block bone graft may influence volume maintenance of the graft.

Microcomputed and histologic evaluation of calvarial bone grafts: a pilot study in humans.

Two evaluation techniques (histology and microcomputed tomography [micro-CT]) were synergistically applied to calvarial bone graft to verify whether additional bone information can be obtained for the assessment of bone grafts. Ten extensive bone defects in the anterior and posterior maxilla or mandible involving crestal bone were treated by grafted blocks and chips of autogenous calvarial bone. The grafts were fixed with lag screws and left to heal for 4 months. No complications were observed. At surgical reentry for implant placement, a cylindric bone biopsy of both graft and native bone was retrieved and analyzed with both micro-CT and standard histology. Two- and three-dimensional (2D, 3D) micro-CT analyses allowed bone connectivity indices to be evaluated. This is useful for estimating bone strength and observing bone structure. The integration of the grafted calvarial bone with the residual bone of the recipient site was considered satisfactory. Histologic analysis allowed observations to be made at a higher resolution. Calvarial bone grafts seem to have positive effects when used as grafting materials. The application of both histologic and micro-CT techniques allows a better evaluation of grafted bone by concurrently allowing 2D and 3D visual and morphometric analysis of bone vitality, structure, turnover, and strength.

Fusion rates of a morselized local bone graft in polyetheretherketone cages in posterior lumbar interbody fusion by quantitative analysis using consecutive three-dimensional computed tomography scans.

BACKGROUND CONTEXT: Posterior lumbar interbody fusion (PLIF) using harvested local bone inserted into a polyetheretherketone (PEEK) cage is a commonly used procedure, but the accurate fusion rate of a cage, cage to bone contact area ratio, and the changes in fusion rate with time after surgery are unknown. PURPOSE: The aim was to conduct a quantitative analysis of the fusion rates and the cage to bone contact area ratios at each period of time using a PEEK cage in PLIF using a consecutive three-dimensional (3D) computed tomography (CT) scan. STUDY DESIGN: This was a prospective study using a consecutive 3D thin-section CT scan. PATIENT SAMPLE: Thirty patients aged between 37 and 73 years set to undergo elective PLIF with PEEK cages and pedicle screw fixation were included in the study. OUTCOME MEASURES: The assessments included the Korean Oswestry Disability Index (K-ODI), Short Form (SF)-36 questionnaire, Visual Analog Scale (VAS) pain score, and dynamic plane radiographs, preoperatively and at 6 and 12 months after surgery. METHODS: Three-dimensional CT scans were performed at 6 and 12 months after surgery. Three-dimensional CT assessments of the following were performed: fusion rate of the cage, cage to bone contact area ratio, and fusion rate of the interbody bone graft besides the cage. RESULTS: The 6-month fusion rate of the segment was 86.7%, which increased to 90.0% at 12 months. The fusion area ratio between the cage area and end plate showed a significant increase from 52.0% at 6 months to 58.5% at 12 months. Regarding the fusion area ratio between the cage and end plate, the ratio between the lower surface of the cage was significantly higher than that of the upper surface. In addition, the K-ODI, SF-36, and VAS values were similar at 6 and 12 months after surgery. CONCLUSIONS: The fusion rate of the PEEK cage used in PLIF measured at 12 months was higher than that measured at 6 months. Therefore, an assessment on the complete fusion of local bone at 12 months after surgery is more accurate.

Long-term block graft stability in thin periodontal biotype patients: a clinical and tomographic study.

PURPOSE: To assess the esthetic and functional outcome, as well as the volume maintenance, of autogenous block grafts placed in anterior sextants of thin periodontal biotype subjects over a long-term period. MATERIALS AND METHODS: Fifteen consecutive patients were followed up yearly for an average of 40 months after autogenous block grafting. Preoperative and postoperative cone beam computed tomographic scans were analyzed to evaluate bone volume maintenance around the implants placed in the grafted sites. Clinical parameters (mucosal recession and implant transparency through the soft tissue) were assessed at prosthesis delivery and follow-up to evaluate the esthetic outcome. Digital photographs were used to confirm clinical outcomes. RESULTS: The average augmentation per site was 2.2 times the initial buccolingual (BL) width, and 97% of the augmented width was maintained after 3.3 years. The difference between preaugmentation and postaugmentation BL width, 3.3 versus 7.4 mm, was statistically significant (P < .0001; CI 95%: 3.4 to 4.9 mm). There was a lack of implant transparency or mucosal recession around the implants in all 15 patients after an average of 40 months. CONCLUSIONS: Autogenous block grafting seems to be a predictable treatment modality to reconstruct alveolar ridge defects in the long term. A thin periodontal biotype did not seem to affect the volume of transplanted bone for the population studied.

Biologic response to autogenous particulate bone graft and shaped titanium mesh in segmental mandibular defect reconstruction.

PURPOSE: This study evaluated the biologic response to titanium mesh and autogenous particulate bone grafts for the reconstruction of segmental mandibular defects in a dog model. MATERIALS AND METHODS: Unilateral 40-mm critical-sized continuity defects of the mandible were made in five beagle dogs. Titanium mesh was shaped and fixed with titanium screws in the defects. Autogenous bone was harvested from the ablated mandible and iliac crest (the ratio of cortical bone:cancellous bone was 3:1) and used to fill the mesh. Two implants were placed into each bone graft. The animals were sacrificed after 6 months. Radiographs, histologic sections, scanning electron microscopy, and energy dispersive spectroscopy were performed to evaluate bone formation and osseointegration of the implants in the reconstructed mandibles. RESULTS: The outline of the reconstructed mandible was satisfactory, and no bone resorption was observed in the defect area. All implants showed excellent osseointegration of the grafted bone. Furthermore, the density of bone formed around the implants was higher than that seen in control samples (intact, ungrafted dog hemimandibles). CONCLUSIONS: Shaped titanium mesh with autogenous particulate bone graft is a predictable method for restoring critical-sized continuity defects of the mandible. Simultaneous implant placement is feasible and the structure of bone formed near implants may be optimal.