种植床自体骨移植在上颌窦闭合式提升中的临床应用

目的评价种植床自体骨植骨行上颌窦闭合式提升后同期植入种植体的临床效果。方法对上颌后牙缺失后剩余牙槽骨高度在6-10mm患者,用中空圆柱钻制备种植床,收集种植床自体骨,行上颌窦闭合式挤压提升后,植入自体骨和ITI种植体,6-9个月后行上部结构修复。结果17例患者共植入25颗种植体,平均提升上颌窦底高度为3.4mm(2-4mm),修复后追踪观察6-36个月,l颗种植体修复6个月后松动拔除。其余24颗种植体平均负载21个月,种植体稳定,未见明显骨吸收,所有病例均无上颌窦并发症。结论严格掌握适应证,种植床自体骨植骨上颌窦闭合式提升同期植入种植体,创伤小、操作较简单,无须开辟第2手术区。     

Repair of a perforated sinus membrane with an autogenous periosteal graft: a study in 24 patients

We describe a technique for repairing a perforation of the sinus membrane with a periosteal graft. Of 117 patients who had augmentation of the sinus floor, the sinus membrane perforated in 24, and these were repaired with autogenous periosteal grafts. Patients were followed up daily for the first 10 days and monthly for the next six months, and clinical and radiographic variables were recorded. Patients had to be free of complications such as wound dehiscence, sinus infections, exposure of the graft, local inflammation, or pain. The radiographs showed correct osseointegration of all implants. Periosteal grafts are an effective alternative for repair of a perforation of the sinus membrane.     

The effects of adjunctive parathyroid hormone injection on bisphosphonate-related osteonecrosis of the jaws: an animal study

Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) is a serious and challenging complication of chronic BP uptake in patients with osteoporosis who require management of skeletal-related events. The efficiency of adjunctive parathyroid hormone (PTH) injection was evaluated after chronic BP administration that was followed by tooth extraction. BRONJ was not observed in any of the subjects in the control groups, while BRONJ was observed in 66% and 22% of the subjects in the tooth extraction group and the tooth extraction with PTH injection group, respectively. In addition the presence and severity of inflammation was lower in the PTH injected group than in the tooth extraction group, but the difference was not statistically significant (P > 0.01). In conclusion, the administration of 30 μg/kg/day PTH during a period of 8 weeks had positive effects on the resolution of BRONJ, but further studies are required to verify the effectiveness of PTH in the treatment of BRONJ.     

Osteogenic efficacy of bone marrow concentrate in rabbit maxillary sinus grafting

Maxillary sinus grafting is required to increase bone volume in the atrophic posterior maxilla to facilitate dental implant placement. Grafting with autogenous bone (AB) is ideal, but additional bone harvesting surgery is unpleasant. Alternatively, bone substitutes have been used but they limit new bone formation. The strategy of single-visit clinical stem cell therapy using bone marrow aspirate concentrate (BMAC) to facilitate new bone formation has been proposed. This study aimed to assess bone regeneration capacity of autologous BMAC mixed with bovine bone mineral (BBM) in maxillary sinus grafting. Twenty-four white New Zealand rabbits were used and their maxillary sinuses were randomly assigned for grafting with 4 different materials. Rates of new bone apposition in augmented sinuses were measured and bone histomorphometry were examined. Significant increase in the quantity of nucleated cells and colony forming unit-fibroblasts were confirmed in BMAC. Mesenchymal stem cells in BMAC retained their in vitro multi-differentiation capability. Higher rates of mineral appositions in the early period were detected in BBM + BMAC and AB than BBM alone, though they are not significantly different. Graft volume/tissue volumes in BBM and BBM + BMAC were found to be higher than those in AB and sham.     

The role,efficacy and outcome measures for teriparatide use in the management of medication-related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a complex disease which can be associated with multiple morbidities and is challenging to treat. This review evaluates the literature on the role and efficacy of teriparatide (TPTD) as a treatment for MRONJ. The clinical, radiological, histopathological and serological parameters used to assess treatment response have been described. Electronic databases were searched to retrieve articles (April 2005 and April 2020) based on strict inclusion criteria. Seventeen articles were included in this review. Of the 91 patients treated; only six received TPTD as a standalone treatment. There were significant variations in defining treatment outcomes and measuring treatment response. The longest follow-up period was 26 months, and 12 studies failed to report follow-up. The overall quality of evidence is weak with potential for a high risk of bias, making it difficult to determine the efficacy of TPTD and its long-term effects. However, TPTD may play a role in the treatment of intractable MRONJ in osteoporotic patients or those unfit for surgery. Therefore, randomized clinical trials on larger patient cohorts with long-term follow-up is required to confirm efficacy, safety and inform treatment indications for TPTD in the treatment of MRONJ.     

Maxillary sinus augmentation model in rabbits: effect of occluded nasal ostium on new bone formation

This study was undertaken to establish an experimental model for maxillary sinus augmentation in rabbits and to clarify the bone response to the occluded nasal ostium. In rabbits without ostial occlusion, the elevation of the sinus mucosa resulted in formation of a subantral hollow space filled with blood clots and granulation tissue 1 week after operation. The newly formed bone filled in the space had a central granulation tissue. The space was almost completely replaced by a normal sinus airspace after 3 weeks. In rabbits with ostial occlusion, a fully formed bone mass was seen after 3 weeks. The mass had both mature trabeculae and peripheral cortical bone containing no sinus airspace after 6 weeks. This animal model for maxillary sinus augmentation may improve our understanding of the bone formation procedure in humans and delineate how sinus air pressure caused by the occluded nasal ostium affects the quantity and fate of newly formed bone.     

Histological evaluation of healing after transalveolar maxillary sinus augmentation with bioglass and autogenous bone

Objectives: The aim was to evaluate histologically the outcome of a bioglass and autogenous bone (at 1 : 1 ratio) composite implantation for transalveolar sinus augmentation. Methods: In 31 patients, during implant installation ca. 4 months after sinus augmentation, biopsies were harvested through the transalveolar osteotomy by means of a trephine bur and non‐decalcified sections through the long axis of the cylinder were produced. After a strict selection process, taking into account the presurgical residual bone height and biopsy length, 8 and 15 biopsies representing the new tissues formed inside the sinus and the transalveolar osteotomy, respectively, qualified for analysis. The tissue fractions occupied by newly formed bone (mineralized tissue+bone marrow), soft connective tissue, residual biomaterial+empty spaces, and debris inside the sinus cavity or the transalveolar osteotomy were estimated. Results: Bone and connective tissue fraction in the newly formed tissues inside the sinus cavity averaged 23.4 ± 13.2% and 54.1 ± 23.5%, respectively. Residual biomaterial, empty spaces, and debris averaged 1.9 ± 3.5%, 10.5 ± 6.3%, and 8.4 ± 14.5%, respectively. In the transalveolar osteotomy, bone and connective tissue fraction averaged 41.6 ± 14.3% and 46.1 ± 13%, respectively, while the amount of residual biomaterial, empty spaces, and debris was 2.8 ± 5%, 4.7 ± 1.9%, and 3.2 ± 2.6%, respectively. Statistically significant differences between the sinus cavity and the transalveolar osteotomy were found only for bone and empty spaces' values (P=0.02 and 0.04, respectively). Conclusion: Sinus augmentation with a bioglass and autogenous bone composite is compatible with bone formation that, in a short distance from the floor of the sinus, shows similar density as that reported previously for other commonly used bone substitutes. New bone fraction inside the transalveolar osteotomy was almost twice as much as in the sinus cavity, while the amount of residual biomaterial was much less than that inside the sinus. To cite this article :
Stavropoulos A, Sima C, Sima A, Nyengaard J, Karring T, Sculean A. Histological evaluation of healing after transalveolar maxillary sinus augmentation with bioglass and autogenous bone.
Clin. Oral Impl. Res. 23 , 2012; 125–131.
doi: 10.1111/j.1600‐0501.2011.02161.x     

Effect of low intensity pulsed ultrasound stimulation on sinus augmentation in rabbits

Objectives

The objective of the present study was to evaluate the efficacy of low intensity pulsed ultrasound stimulation (LIPUS) and to determine the optimal frequency for enhancing bone regeneration in sinus augmentation using a rabbit model.

Material and methods

Thirty male rabbits underwent sinus augmentation. Two rectangular nasal bone windows were outlined bilaterally. LIPUS was applied at two different frequencies (1 MHz and 3 MHz) on experimental sites daily for 2, 4 and 8 weeks. Each histological area of the experimental and control sites was divided into upper and lower parts from the parietal region to a depth of 5 mm. Each area of new bone was measured.

Results

At 2, 4 and 8 weeks, the experimental sites in the 1 MHz group exhibited significantly more new bone growth than the control sites in both the upper and lower parts. When the upper and lower parts of each area were measured in combination there was a statistical difference between the test and control sites in the 1 MHz group at 2, 4 and 8 weeks; however, there were no statistical differences between the test and control sites in the 3 MHz group.

Conclusions

The results suggest that clinical application of LIPUS for sinus augmentation may promote new bone formation, and that the effect of LIPUS for sinus augmentation at a frequency of 1 MHz was greater than at 3 MHz until 8 weeks after sinus augmentation.     

Histomorphometric results of different grafting materials and effect of healing time on bone maturation after sinus floor augmentation: a systematic review and meta‐analysis

The aim of this systematic review was to evaluate histomorphometric variables, the amount of new bone (NB), residual graft (RG) particles and soft tissue (ST), related to various grafting materials and assess the effect of graft healing time on different histomorphometric outcomes. Studies that were published before October 2015 were electronically and manually searched in three databases. We included human studies that reported the amount of NB, RG and ST in the biopsies taken from the grafted sinuses. Based on the applied grafting materials, extracted data were categorized into different groups. Furthermore, extracted data were classified into three groups based on healing time: (i) ≤ 4.5 mo; (ii) 4.5–9 mo; and (iii) ≥ 9–13.5 mo. The search provided 791 titles. Full text analysis was performed for 258 articles resulting in 136 studies that met the inclusion criteria. Autogenous bone (AB) resulted in the highest amount of NB and lowest amount of RG compared to other grafting materials. Based on this meta‐analysis, a significant difference was noticed in the amount of NB formation in grafts with a healing time of > 4.5 mo when compared to the grafts with less healing time. However, when comparing biopsies taken at 4.5–9 mo of healing (average = 6.22 mo) to the ones taken at ≥ 9–13.5 mo (average = 10.36 mo), no significant difference was noticed in the amount of NB formation of various grafts except allografts that resulted in a significantly higher percentage of NB at 9.5 mo of healing. Based on histomorphometric analysis, AB results in the highest amount of NB formation in comparison to the other grafting materials. Bone substitute materials (allografts, alloplastic materials and xenografts) seem to be good alternatives to autogenous bone and can be considered as grafting materials to avoid disadvantages related to AB, including morbidity rate, limited availability and high volumetric change. Combining AB with alloplastic materials and xenografts brings no significant advantages regarding NB formation.     

Retrospective analysis of time-related three-dimensional iliac bone graft resorption following sinus lift and vertical augmentation in the maxilla

The atrophic maxilla frequently requires bone grafting using an onlay graft (OG) or sinus lifting (SL) before implant rehabilitation. The resorption of bone grafts is influenced by the time until implantation, quality of donor bone, and grafting technique. The aim of this study was to investigate the impact of both grafting techniques on the time-related resorption of autologous iliac bone graft. Forty-three patients underwent either onlay grafting or a sinus lift at 73 sites in the maxilla. Graft height was measured by cone beam computed tomography after augmentation and during follow-up for up to 12 months prior to implant insertion. The effect of time and technique on graft resorption was evaluated retrospectively. The reduction in bone graft height was greater for OG than SL over the investigated time intervals (OG = 51%, SL = 28%; P = 0.002). Each technique followed a specific course of resorption, which was independent of the initial graft height and could be calculated by a non-linear regression model. Iliac bone graft undergoes rapid resorption when used as an OG prior to implant insertion. For SL, this resorption is reasonably lower. This is especially crucial to determine the optimal time for implant insertion after graft healing to improve implant survival.     

Bisphosphonate‐associated osteonecrosis of the jaw,with healing after teriparatide:a review of the literature and a case report

This paper reports the case history of a patient who had bisphosphonate‐associated osteonecrosis of the jaw (ONJ) in which adjunctive treatment with teriparatide was used. The patient was treated for 5 years with alendronate for osteoporosis and developed ONJ after extraction of maxillary teeth. An implant was placed at the site of the extracted teeth. The pathology report confirmed the clinical diagnosis of ONJ; treatment was changed from alendronate to teriparatide and the ONJ resolved. To our knowledge, this is the third case history reported in the literature in which teriparatide was successfully used as adjunct therapy in ONJ because it has an anabolic effect and presumed role in accelerating bone healing. ONJ is a serious but infrequent condition that has been recently associated with nitrogen‐containing bisphosphonate therapy. Teriparatide may be a useful adjunctive therapy when ONJ develops.     

不同植骨材料在上颌窦开窗提升植骨同期种植体植入术的初期临床效果评价

目的 对不同植骨材料在上颌窦开窗提升植骨同期种植体植入术的初期临床效果进行评价。方法 根据上颌窦植骨材料的不同分为3组：β-磷酸三钙（β-TCP）组;同种异体冻干骨组;β-TCP+同种异体冻干骨组。分别评估各组术后临床情况、修复时移植骨垂直高度保留率、修复时的种植体的稳定系数,并加以比较。结果 3组初期临床效果良好,无失败病例。β-TCP组垂直骨高度保留率（58.82±8.17）%,种植体的稳定系数75.36±3.72。同种异体冻干骨组垂直骨高度保留率（61.81±10.26）%,种植体的稳定系数78.20±3.77。β-TCP+同种异体冻干骨组垂直骨高度保留率（60.56±7.06）%,种植体的稳定系数75.06±4.20。各组数据无统计学差异。结论 3种不同植骨材料在上颌窦开窗植骨同期种植体植入术中均具有良好初期临床效果。     

Influence of decortication of the donor bone on guided bone augmentation. An experimental study in the rabbit skull bone

The aim of the present study was to evaluate if early access to the endosteal bone compartment by removal of the outer cortical bone plate will enhance bone augmentation in a secluded space. Two titanium cylinders were placed on the skull of each of 8 rabbits. Each cylinder was placed into a circular slit, secured to the skull bone via two mini-screws and supplied with a titanium lid. On the test side, the outer plate of the cortical bone, demarcated by the slit, was removed. The subsequent bleeding resulted in blood fill of the cylinders to various degrees. On the control side, the corfical bone plate was left intact and no bleeding was observed at the time of the placement of the titanium lids. After 3 months, the animals were sacrificed to obtain histology and histomorphometry. No differences in the total amount of augmented bone tissue, in relation to the total experimental area (75.5% +/- 10.9% at the test sites and 71.2% +/- 13.5% at the control sites) or of the augmented mineralized bone tissue in relation to the total amount of augmented bone tissue, was revealed (17.8% +/- 3.0% and 16.0% +/- 4.9% respectively). There was no difference in the morphological appearance of the augmented bone between test and control sites and there were no obvious similarities in the appearance between the newly formed bone tissue and the donor bone. The augmented bone consisted of slender bone trabeculae, distributed in abundant marrow spaces. A conspicuous finding was that the bone trabeculae tended to climb along the inner walls of the titanium cylinder. It is concluded that decortication of the calvarial bone in the rabbit does not result in more bone formation beyond the skeletal envelope after a healing period of 3 months compared to no removal of the cortical bone plate inside a secluded experimental area.