Sebastian Sauerbier

Surgical treatment of bisphosphonate-associated osteonecrosis of the jaw: Technical report and follow up of 21 patients

INTRODUCTION Bisphosphonates are used to reduce skeletal related events in patients with bone consuming diseases such as osteoporosis and bone metastases. However recently there has been an increased awareness of bisphosphonate-associated necrosis of the jaws (BP-ONJ). Many authors propose conservative management in these cases but invariably the problem is not treated successfully allowing the bone defect to worsen. Recently there has been a move to treat this problem surgically. The aim of this retrospective study was to provide a surgical solution for patients suffering from BP-ONJ. MATERIALS AND METHODS All patients presenting with BP-ONJ were treated with bone debridement of the affected area and multilayer wound closure. The considered variables were: gender, age, underlying diagnosis, type of bisphosphonate (BP) used, duration of bisphosphonate use, route of administration, location of the osteonecrosis, clinical symptoms, association with dental treatment and surgical outcome. RESULTS Nineteen cases of a total of 21 demonstrated no recurrence of osteonecrosis during follow up (Mean 16 months - Range 12-24 months). One patient with a bilateral defect showed a dehiscence on one side and a small fistula on the contralateral side 6 weeks post-operatively and required revision surgery. Another patient developed a fistula after 4 weeks that was treated successfully with antibiotics and curettage. No patients had evidence of exposed bone, bland mucosa nor pain at the surgical site. CONCLUSION The technique described can be recommended for patients with BP-ONJ if a conservative treatment fails.

Maxillary sinus floor elevation with bovine bone mineral combined with either autogenous bone or autogenous stem cells: a prospective randomized clinical trial.

AIM To assess whether differences occur in bone formation after maxillary sinus floor elevation surgery with bovine bone mineral (BioOss(®)) mixed with autogenous bone or autogenous stem cells. The primary endpoint was the percentage of new bone three months after the elevation procedure. MATERIAL AND METHODS In a randomized, controlled split-mouth design, in 12 consecutive patients (age 60.8 ± 5.9 years, range 48-69 years) needing reconstruction of their atrophic maxilla, a bilateral sinus floor augmentation procedure was performed. Randomly, on one side the augmentation procedure was performed with bovine bone mineral (BioOss(®)) seeded with mononuclear stem cells harvested from the posterior iliac crest (test group) while BioOss(®) mixed with autogenous bone (harvested from the retromolar area) was applied on the contra-lateral side (control group). On 14.8 ± 0.7 weeks after the sinus floor elevation, biopsies from the reconstructed areas were taken at the spots where subsequently the endosseous implants were placed. The biopsies were histomorphometrically analyzed. RESULTS Significantly more bone formation was observed in the test group (17.7 ± 7.3%) when compared with the control group (12.0%± 6.6; P=0.026). In both the test and control group, all implants could be placed with primary stability. In one patient, not all biopsies contained BioOss(®). This patient was excluded from analysis. CONCLUSION Mesenchymal stem cells seeded on BioOss(®) particles can induce the formation of a sufficient volume of new bone to enable the reliable placement of implants within a time frame comparable with that of applying either solely autogenous bone or a mixture of autogenous bone and BioOss(®). This technique could be an alternative to using autografts.

The development of plate osteosynthesis for the treatment of fractures of the mandibular body : A literature review

PURPOSE Today plate and screw osteosynthesis of mandibular fractures is a standard procedure in routine clinical practice. In this review, the breakthroughs and drawbacks of the development of this important aspect of maxillofacial surgery are followed-up. METHODS Medline search of relevant English and German literature. RESULTS In 1886, Carl Hansmann was the first who applied steel screws and plates. Until today the material, the types of plates and applications have been continually improved. Over the last two decades miniplate osteosynthesis has induced a revolution in mandibular fracture treatment. The modern systems provide better handling, higher stability and less pressure on the bone. CONCLUSION Modern miniplates have great advantages, like the intra-oral approach and the easy adaptability. In addition, it is no longer necessary to expose bone as extensively.

In vivo comparison of hard tissue regeneration with human mesenchymal stem cells processed with either the FICOLL method or the BMAC method.

OBJECTIVE To compare new bone formation in maxillary sinus augmentation procedures using biomaterial associated with mesenchymal stem cells (MSCs) separated by two different isolation methods. BACKGROUND In regenerative medicine open cell concentration systems are only allowed for clinical application under good manufacturing practice conditions. METHODS Mononuclear cells, including MSCs, were concentrated with either the synthetic polysaccharide (FICOLL) method (classic open system--control group, n = 6 sinus) or the bone marrow aspirate concentrate (BMAC) method (closed system--test group, n = 12 sinus) and transplanted in combination with biomaterial. A sample of the cells was characterized by their ability to differentiate. After 4.1 months (SD +/- 1.0) bone biopsies were obtained and analyzed. RESULTS The new bone formation in the BMAC group was 19.9% (90% confidence interval [CI], 10.9-29), and in the FICOLL group was 15.5% (90% CI, 8.6-22.4). The 4.4% difference was not significant (90% CI, -4.6-13.5; p = 0.39). MSCs could be differentiated into osteogenic, chondrogenic, and adipogenic lineages. CONCLUSION MSCs harvested from bone marrow aspirate in combination with bovine bone matrix particles can form lamellar bone and provide a reliable base for dental implants. The closed BMAC system is suited to substitute the open FICOLL system in bone regeneration procedures.

Mesenchymal stem cells and inorganic bovine bone mineral in sinus augmentation: comparison with augmentation by autologous bone in adult sheep

Our aim was to compare the osteogenic potential of mononuclear cells harvested from the iliac crest combined with bovine bone mineral (BBM) (experimental group) with that of autogenous cancellous bone alone (control group). We studied bilateral augmentations of the sinus floor in 6 adult sheep. BBM and mononuclear cells (MNC) were mixed and placed into one side and autogenous bone in the other side. Animals were killed after 8 and 16 weeks. Sites of augmentation were analysed radiographically and histologically. The mean (SD) augmentation volume was 3.0 (1.0) cm(3) and 2.7 (0.3) cm(3) after 8 and 16 weeks in the test group, and 2.8 (0.3) cm(3) (8 weeks) and 2.8 (1.2) cm(3) (16 weeks) in the control group, respectively. After 8 weeks, histomorphometric analysis showed 24 (3)% BBM, and 19 (11)% of newly formed bone in the test group. The control group had 20 (13%) of newly formed bone. Specimens after 16 weeks showed 29 (12%) of newly formed bone and 19 (3%) BBM in the test group. The amount of newly formed bone in the control group was 16 (6%). The results show that mononuclear cells, including mesenchymal stem cells, in combination with BBM as the biomaterial, have the potential to form bone.

Bone regeneration in sinus lifts: comparing tissue-engineered bone and iliac bone.

Lifting of the sinus floor is a standard procedure for bony augmentation that enables dental implantation. Although cultivated skin and mucosal grafts are often used in plastic and maxillofacial surgery, tissue-engineered bone has not achieved the same success. We present the clinical results of dental implants placed after the insertion of periosteum-derived, tissue-engineered bone grafts in sinus lifts. Periosteal cells were isolated from biopsy specimens of periosteum, resuspended and cultured. The cell suspension was soaked in polymer fleeces. The cell-polymer constructs were transplanted by sinus lift 8 weeks after harvesting. The patients (n=35) had either one or both sides operated on. Seventeen had a one-stage sinus lift with simultaneous implantation (54 implants). In 18 patients the implants were inserted 3 months after augmentation (64 implants). Selected cases were biopsied. A control group (41 patients: one stage=48 implants, two stage=135 implants) had augmentation with autologous bone only. They were followed up clinically and radiologically for at least 24 months. Both implants and augmentation were significantly more successful in the control group. Failure of augmentation of the tissue-engineered bone was more common after large areas had been augmented. Eleven implants were lost in the study group and only one in the control group. Lifting the sinus floor with autologous bone is more reliable than with tissue-engineered transplants. Although lamellar bone can be found in periosteum-derived, tissue-engineered transplants, the range of indications must be limited.

Application of a new chair-side method for the harvest of mesenchymal stem cells in a patient with nonunion of a fracture of the atrophic mandible – A case report

PURPOSE This case report describes a new clinical method for chair-side processing of a cell mixture which contains mesenchymal stem cells (MSCs) which was applied for the first time in the treatment of a nonunion of an atrophic fractured mandible. METHODS Bone marrow was aspirated and a corticocancellous bone graft was harvested from the iliac crest of a 56-year-old woman with medical comorbidities and a fracture of the atrophic mandible. The fracture was stabilized with a reconstruction bone plate, and mononuclear cells including MSCs were concentrated by centrifugation and applied in combination with a particulate bone transplant. A sample of the grafted cells was characterized by flow cytometric analysis and by their ability to differentiate into various cell types. RESULTS The fracture healed uneventfully. No complications occurred during the 4-month follow-up. CONCLUSION Adding MSCs is a feasible alternative to enhance bone healing. This chair-side method requires little training and no cell laboratory support.

Maxillary sinus floor elevation surgery with BioOss® mixed with a bone marrow concentrate or autogenous bone: test of principle on implant survival and clinical performance

The purpose of this study was to assess implant survival and 1-year clinical performance of implants placed in the posterior maxilla that had been subjected to maxillary sinus floor elevation surgery with bovine bone mineral (BioOss®) mixed with autogenous bone marrow concentrate or autogenous bone. In a randomized, controlled, split-mouth design study, a bilateral sinus floor augmentation procedure was performed in 12 edentulous patients. At random, one side was treated with BioOss® seeded with an iliac crest bone marrow concentrate enriched in mesenchymal stem cells (test side) and the other with BioOss® mixed with autogenous bone (control side). Three to four months after augmentation, 66 implants were placed. Implant survival, plaque, gingival, and bleeding indices, probing depth, and peri-implant radiographic bone levels were assessed at baseline and 12 months after functional loading. During osseointegration, three implants failed on the test side (two patients) and no implants failed on the control side, resulting in 3-month survival rates of 91% and 100%, respectively. No implants were lost after functional loading and no differences in soft tissue parameters or peri-implant bone loss were observed between the control and test sides. After 1 year in function, no clinically relevant differences were observed regarding soft tissue parameters or peri-implant bone loss.

Tissue-Engineered Polymer-Based Periosteal Bone Grafts for Maxillary Sinus Augmentation: Five-Year Clinical Results

PURPOSE Augmentation of the maxillary sinus with allogenic or alloplastic materials, as well as autologous bone grafts, has inherent disadvantages. Therefore, the aim of our study was to evaluate the long-term clinical repair effect of autologous periosteal bone grafts on atrophic maxillary bone. PATIENTS AND METHODS In the present retrospective cohort study, augmentation of the edentulous atrophic posterior maxilla was performed using autologous tissue-engineered periosteal bone grafts based on bioresorbable polymer scaffolds and, in a 1-step procedure, simultaneous insertion of dental implants. The clinical evaluation of 10 patients was performed by radiologic assessment of bone formation, with a follow-up of 5 years. Bone formation was further documented by measuring the bone height and by histologic examination. RESULTS Excellent clinical and radiologic results were achieved as early as 4 months after transplantation of the periosteal bone grafts. The bone height remained significantly (P < .05) greater (median 14.2 mm) than the preoperative atrophic bone (median 6.9 mm) during the 5-year observation period. Histologically, the bone biopsy specimens of 2 patients obtained after 6 months showed trabecular bone with osteocytes and active osteoblasts. No signs of bone resorption, formation of connective tissue, or necrosis were seen. CONCLUSION Our results suggest that the transplantation of autologous periosteal bone grafts and implantation of dental implants in a 1-step procedure is a reliable procedure that leads to bone formation in the edentulous posterior maxilla, remaining stable in the long term for a period of at least 5 years.

Making bone II: maxillary sinus augmentation with mononuclear cells—case report with a new clinical method

We report a simplified method of using bone marrow aspirate concentrate (BMAC™) to regenerate hard tissue. The results suggest that BMAC™ combined with a suitable biomaterial can form sufficient bone within 3 months for further implants to be inserted, and at the same time minimise morbidity at the donor site.