Complications after maxillary sinus augmentation: a case report

The maxillary sinus grafting procedure has been routinely performed with predictable results. The procedure has proven to be an acceptable modality for bone augmentation to provide a base for endosseous implant placement. Several complications have been documented in the literature. They vary from sinus membrane perforation to formation of a mucocele inside the bony graft mass. This report describes a serious complication after a maxillary sinus augmentation that resulted in obliteration of the sinus.     

Porous hydroxyapatite as a bone graft substitute in maxillary augmentation. An histometric study

A porous HA matrix, which is available for clinical use, was compared with split rib autografts after maxillary contour augmentation in 17 dogs. Specimens were retrieved at 3, 6, 12, 24 and 48 months and undecalcified sections were prepared for microscopy and histometry. The implant and graft cross sectional areas did not change with time, although mechanical trauma caused early changes in implant area in some specimens. In all implants, union with the maxillary cortex occurred along with substantial bone ingrowth. An area under the periosteum contained soft tissue ingrowth. In all grafts, except one, union also occurred. However, bone ingrowth into the cancellous spaces was not apparent, or minimal. The implant specimens were composed of 34.7% HA matrix, 23.9% bone and 41.3% soft tissue. The bone ingrowth remained permanent for the study duration. A 6.5% decrease in HA matrix occurred between the 24 and 48 month time intervals, suggesting the presence of microporous surface resorption. The graft specimens were composed of 55.8% bone and 44.2% non-mineralized tissue, without change over time. The similarity in mineralized tissue composition of the implants (58.6%) and grafts (55.8%) supported the thesis that a porous HA matrix can function as a bone graft substitute.     

一种空间维持装置应用于上颌窦骨增量术的实验研究

目的 观察一种空间维持装置进行上颌窦骨增量术后新骨形成情况,并探究上颌窦黏膜穿孔对该技术的影响。方法 采用纯钛制作上颌窦黏膜提升空间维持装置,3只比格犬拔除上颌后牙构建上颌后牙缺失上颌窦区骨量不足的动物模型,自然愈合3个月后行双侧的上颌窦黏膜提升,随机选取一侧在黏膜完整情况下放入空间维持装置,对侧在黏膜穿孔情况下放入空间维持装置。3个月后处死实验动物,制取标本进行组织学分析。结果 空间维持装置内部可见新骨呈帽状凸起,与提升空间的形态相适应,但尚未充满整个提升的空间,窦底骨与新骨之间界限明显,新骨为未成熟的编织骨,疏松排列的骨小梁交错成网,骨小梁内可见软骨陷窝分布;无骨粉充填的上颌窦骨增量术在黏膜完整、穿孔后新骨面积分别为（8.17±5.63） mm2,（9.92±4.65） mm2,差异没有统计学意义。结论 单纯利用空间维持装置进行的上颌窦骨增量术可以诱导新骨形成,且较小的黏膜穿孔对其没有影响,具体新骨形成机制仍有待探索。     

Effect of maxillary sinus floor augmentation on sinus membrane thickness in computed tomography

Background: Little is known about maxillary sinus compliance, i.e., the intrinsic potential of the sinus membrane to resume its homeostatic status after the surgical trauma caused by sinus floor elevation. The aim of the present study is to investigate the effect of maxillary sinus floor augmentation on sinus membrane thickness. Methods: Within‐patient comparison of computed tomographic scans before bone grafting versus 4 to 6 months after bone grafting was performed. Changes in membrane thickness were evaluated in 65 maxillary sinus floor augmentation procedures via a lateral approach in 35 patients without clinical signs of sinus pathology at any time. Results: Sinus membrane thickness differed significantly before (0.8 ± 1.2 mm) versus after (1.5 ± 1.3 mm) augmentation surgery (P <0.001), with a mean increase of 0.8 ± 1.6 mm (maximum: 4.4 mm). Only 28% of augmented sinuses did not show membrane thickening. In non‐augmented control sinuses, there was no evidence of membrane thickness increase. Conclusions: The results indicate that the maxillary sinus membrane, even in healthy clinical conditions, undergoes morphologic modifications after sinus floor elevation, yet membrane reactions demonstrate significant variability. Future research on the effect of augmentation surgery on maxillary sinus physiology is recommended.     

Correction to: Influence of the use of autogenous bone particles to close the access window after maxillary sinus floor augmentation: a micro-computed tomography and positron emission tomography study in rabbits

Oral and Maxillofacial Surgery -     

Effects of boric acid on bone formation after maxillary sinus floor augmentation in rabbits

Purpose

Augmentation of the maxillary sinus floor with bone grafting is commonly used for successful treatment of edentulous posterior maxilla with dental implants, and it is essential to maintain good bone volume and quality for long-term success of dental implants. The aim of this experimental study was to investigate the local and systemic effects of boric acid on new bone formation after maxillary sinus floor augmentation (MSFA).

Materials and methods

Twenty-four male, New Zealand rabbits were randomly divided into three groups with eight rabbits each, and bilateral MSFA was performed in each animal. An autogenous bone/xenograft mixture was used to augment the maxillary sinuses in each group. Group 1 was determined as control with no additional materials, whereas 3 mg/kg boric acid (BA) was added to the mixture in group 2, and 3 mg/kg boric acid solution added to drinking water daily in group 3.

Results

The animals were sacrificed and also histologic, histomorphometric, and immunnohistochemical analyses were performed at weeks 4 and 8. At week 4, bone regeneration was better in the local BA group than in the control and systemic BA groups (p?<?0.05). However, no significant difference was found among the groups in terms of bone regeneration at the end of week 8 (p?>?0.05).

Conclusion

Significant higher new bone formation was revealed by BA at early healing especially with local application. BA may be a therapeutic option for improving the bone regeneration.

     

Evaluation of bone volume changes after sinus floor augmentation with autogenous bone grafts

The aim of this study was to establish an objective method for quantitative evaluation of bone volume change after sinus augmentation. 11 sinuses in 9 patients were evaluated by computed tomography images taken before treatment (T0), and 3 months (T1) and at least 1 year (T2) after sinus augmentation. Based on the 3D digital subtraction technique, augmented bone images were extracted and bone volumes were calculated from voxel numbers of the extracted images. The mean augmented bone volumes at T1 and T2 were 2.46 cm3 and 1.85 cm3, respectively. These bone volume changes were statistically significant and the mean bone volume change ± SE was -24.8% ± 6.1%. Loss of augmented bone was observed in all except one of the patients. The correlation coefficient between bone volume change and elapsed time was -0.64, which was statistically significant and indicated that bone resorption progressed with elapse of time after sinus augmentation. The authors' method of analysis enabled visualization of augmented bone and objective assessment of bone volume change. Within the limited number of cases, the present investigation demonstrated a significant decrease in augmented bone volume between 3 and 23 months after surgery.     

Histomorphometric comparison of maxillary pristine bone and composite bone graft biopsies obtained after sinus augmentation

Introduction: Sinus grafting is a technique oriented to facilitate implant placement in posterior atrophic maxillae. Several modifications of the original technique and a wide variety of materials have been proposed; most of them associated with implant survival rates. However, the quality of the bone obtained after the application of certain grafting materials has not been fully elucidated yet. The aims of this multicenter study were to analyse histomorphometrical samples obtained 6 months after sinus grafting using a composite graft consisting of anorganic bovine bone (ABB)+ autologous bone (AB), and to compare these samples with maxillary pristine bone biopsies. Material and methods: Ninety maxillary sinus augmentations were performed for delayed implant placement (N=90) in 45 consecutive patients (test group). Bone cores were harvested 6 months after grafting for histomorphometric and ultrastructural study. Control pristine bone biopsies were taken from the posterior maxilla of 10 patients (control). Bone radiographic changes were assessed up to 24 months after implant loading. Results: The total mean values after analysis of test cores revealed a proportion of 46.08±16.6% of vital bone, 42.27±15.1% of non‐mineralized connective tissue, and 37.02±25.1% of the remaining ABB particles. Significant bone remodeling activities were noticed in sinus grafting samples when compared with pristine bone. A statistically significant difference was observed in the number of osteoid lines between two groups, with higher values in the test one (15.1±11.48% vs. 2.5±2.2%, P=0.0005). Ultrastructural study showed that vital trabecular bone was in intimal contact with ABB particles. Radiographic analysis revealed that the higher the proportion of remaining ABB, the lower the total vertical resorption of the graft. Conclusion: Sinus grafting constitutes an excellent model for the study of de novo bone formation patterns and graft consolidation, when a combination of different bone substitutes is applied. The combination of ABB+AB yields highly satisfactory outcomes from both a clinical and a histologic perspective. To cite this article:
Galindo‐Moreno P, Moreno‐Riestra I, Ávila G, Fernández‐Barbero JE, Mesa F, Aguilar M, Wang H‐L, O'Valle F. Histomorphometric comparison of maxillary pristine bone and composite bone graft biopsies obtained after sinus augmentation.
Clin. Oral Impl. Res. 21 , 2009; 122–128.     

Histologic findings in sinus augmentation with autogenous bone chips versus a bovine bone substitute

PURPOSE: The aim of this study was to compare a bovine bone substitute (Bio-Oss) to autogenous bone with respect to its value as a material for sinus augmentation. MATERIALS AND METHODS: In 10 beagle dogs 12 months of age, the 3 maxillary premolars were extracted on both sides. Six weeks later, 2 cavities of predefined size were produced in the region of the nasal cavity. The antral window was 25 mm long and had a vertical extension of 7 mm. Two Frialit-2 implants (3 x 8 mm) were placed in each bone defect (n = 20). Every implant was primarily stable because of fixation in native bone. In each maxilla, 1 bone defect was filled with autogenous bone harvested from the mandible and 1 was filled with Bio-Oss (material selected at random). The animals were sacrificed at 90 and 180 days, and histologic specimens were examined and the results subjected to statistical analysis by the Wilcoxon test for paired observations. RESULTS: No healing problems were observed. Histologically, after 90 days the volume of the augmentation showed a reduction of 14.6 +/- 4.4% within the Bio-Oss group and 3.8 +/- 2.5% in the group with autogenous bone. Bone-implant contact of 52.16 +/- 13.15% in the Bio-Oss group and 60.21 +/- 11.46% in the autogenous bone group was observed. At 180 days, the Bio-Oss group showed bony ingrowth of the substitute, whereas in the autogenous group a differentiation from original bone could no longer be made. The volume reduction was 16.5 +/- 8.67% in the Bio-Oss group and 39.8 +/- 16.14% in the autogenous group. Bone-implant contact of 63.43 +/- 19.56% in the Bio-Oss group and 42.22 +/- 12.80% in the autogenous bone group was measured. DISCUSSION AND CONCLUSION: The results indicated that because of the nonresorptive properties of the bone substitute Bio-Oss, regeneration of the defects is achievable. It was demonstrated that the bone substitute seemed to behave as a permanent implant. The volume of the area augmented by autogenous bone decreased over the observation period.     

关于上颌窦底提升术骨增量策略的研究进展

上颌后牙区骨高度不足是种植手术常见的问题之一。而上颌窦底提升术拓宽了上颌后牙区种植的适应证。随着临床技术的进步和口腔材料学的发展,上颌窦底提升术的植骨策略不断更新。尽管上颌窦内的成骨机制尚未完全阐明,但上颌窦底提升术不植骨已经得到了越来越多的认可,如何选择和把握适应证是该策略的关键。经典传统的骨移植材料存在不同程度的缺陷,新型骨组织工程辅助材料应运而生,部分已得到临床应用。该文就上颌窦底提升术是否植骨、骨移植材料等方面的研究进展作一综述。     

上颌窦底提升及人工骨粉植入的动物实验研究

目的:评价金骨威骨粉用于上颌窦底提升后植骨的可行性.方法:在兔上颌窦底提升动物模型中植入金骨威和自体骨进行对照研究.用影像学和组织形态学的方法评价植骨后不同时期的效果.观察灰度值、成骨细胞数量、新生骨面积和金骨威材料的剩余面积,对金骨威植骨后的成骨过程做一阐述.通过自体骨植骨后获得的各项数据,比较金骨威与自体骨之间成骨的差异.结果:金骨威植骨区在2周时灰度值很低,随着时间的增加,灰度逐渐上升,在12周时与自体骨无明显差异.在金骨威植骨区成骨细胞数目随着时间的延长,成骨细胞数量逐渐降低.12周时,金骨威植骨区和自体骨植骨区的成骨细胞数量没有统计学差异.金骨威植骨区的材料剩余面积随着时间的延长逐渐下降,且降解速度相对较快.结论:在兔上颌窦底提升植骨模型中单独使用金骨威作为植骨材料是可行的.     

Platelet-rich plasma activity on maxillary sinus floor augmentation by autologous bone

OBJECTIVES: This work aims to evaluate the regenerative potential of platelet-rich plasma (PRP) on an implant site of peculiar clinical impact, such as sinus augmentation. MATERIAL AND METHODS: Sixteen consenting patients (11 females and five males), with symmetrical maxillary sinus atrophy, underwent bilateral sinus floor augmentation, using autologous (iliac crest) bone on one side and PRP plus autologous bone contralaterally. Implants were inserted 4, 5, 6 and 7 months after surgery in the patients randomly split into four groups. Orthopantomographies, computed tomography with transverse image digital reconstructions and densitometries were used to monitor the treatment progress. A core biopsy was performed at the site of implant. RESULTS: Clinical performance across both sites showed no statistical significance (P=0.414). Densitometric values were higher at PRP sites (mean Hounsfield units approximately +57%), even if densitometry converged in the two sites 8 months after surgery. Histology documents enhanced bone activities in sites treated with PRP, 4 months after surgery. Reduced bone activity was observed in both sites 5, 6 and 7 months after surgery. Bone amount, higher in sites treated with PRP (mean trabecular bone volume approximately +37%), decreased in both sites over time. CONCLUSIONS: Our results seem to indicate a certain regenerative potential of PRP when used with autologous bone. The effect of this enhancement of bone regeneration appeared to be restricted to shorter treatment times. A progressive extinguishment of the PRP effect is recorded after an interval longer than 6-7 months.     

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