Assessment of the osteogenic effect after maxillary sinus floor elevation and simultaneous implantation with or without bone grafts by analyzing trabecular bone parameters: a retrospective study

Abstract Objective: The aim of this population-based retrospective study was to compare the osteogenic effect of newly formed bone after maxillary sinus floor elevation (MSFE) and simultaneous implantation with or without bone grafts by quantitatively analyzing trabecular bone parameters. Methodology: A total of 100 patients with missing posterior maxillary teeth who required MSFE and implantation were included in this study. Patients were divided into two groups: the non-graft group (n=50) and the graft group (n=50). Radiographic parameters were measured using cone beam computed tomography (CBCT), and the quality of newly formed bone was analyzed by assessing trabecular bone parameters using CTAn (CTAnalyzer, SkyScan, Antwerp, Belgium) software. Results: In the selected regions of interest, the non-graft group showed greater bone volume/total volume (BV/TV), bone surface/total volume (BS/TV), trabecular number (Tb. N), and trabecular thickness (Tb. Th) than the graft group (p<0.001). The non-graft group showed lower trabecular separation (Tb. Sp) than the graft group (p<0.001). The incidence of perforation and bleeding was higher in the graft group than in the non-graft group (p<0.001), but infection did not significantly differ between groups (p>0.05). Compared to the graft group, the non-graft group showed lower postoperative bone height, gained bone height and apical bone height (p<0.001). Conclusion: MSFE with and without bone grafts can significantly improve bone formation. In MSFE, the use of bone grafts hinders the formation of good quality bone, whereas the absence of bone grafts can generate good bone quality and limited bone mass.

Expert consensus on the bone augmentation surgery for alveolar bone defects / 口腔疾病防治

@#Alveolar bone is an important anatomic basis for implant-supported denture restoration, and its different degrees of defects determine the choices of bone augmentation surgeries. Therefore, the reconstruction of alveolar bone defects is an important technology in the clinical practice of implant restoration. However, the final reconstructive effect of bone quality, bone quantity and bone morphology is affected by many factors. Clinicians need to master the standardized diagnosis and treatment principles and methods to improve the treatment effect and achieve the goal of both aesthetic and functional reconstruction of both jaws. Based on the current clinical experience of domestic experts and the relevant academic guidelines of foreign counterparts, this expert consensus systematically and comprehensively summarized the augmentation strategies of alveolar bone defects from two aspects: the classification of alveolar bone defects and the appropriate selection of bone augmentation surgeries. The following consensus are reached: alveolar bone defects can be divided into five types (Ⅰ-0, Ⅰ-Ⅰ, Ⅱ-0, Ⅱ-Ⅰ and Ⅱ-Ⅱ) according to the relationship between alveolar bone defects and the expected position of dental implants. A typeⅠ-0 bone defect is a bone defect on one side of the alveolar bone that does not exceed 50% of the expected implant length, and there is no obvious defect on the other side; guided bone regeneration with simultaneous implant implantation is preferred. Type Ⅰ-Ⅰ bone defects refer to bone defects on both sides of alveolar bone those do not exceed 50% of the expected implant length; the first choice is autologous bone block onlay grafting for bone increments with staged implant placement or transcrestal sinus floor elevation with simultaneous implant implantation. Type Ⅱ-0 bone defects show that the bone defect on one side of alveolar bone exceeds 50% of the expected implant length, and there’s no obvious defect on the other side; autologous bone block onlay grafting (thickness ≤ 4 mm) or alveolar ridge splitting (thickness > 4 mm) is preferred for bone augmentation with staged implant placement. Type Ⅱ-Ⅰ bone defects indicate that the bone plate defect on one side exceeds 50% of the expected implant length and the bone defect on the other side does not exceed 50% of the expected implant length; autologous bone block onlay grafting or tenting techniques is preferred for bone increments with staged implant implantation. Type Ⅱ-Ⅱ bone defects are bone plates on both sides of alveolar bone those exceed 50% of the expected implant length; guided bone regeneration with rigid mesh or maxillary sinus floor elevation or cortical autologous bone tenting is preferred for bone increments with staged implant implantation. This consensus will provide clinical physicians with appropriate augmentation strategies for alveolar bone defects.

The role of the membrane of the maxillary sinus in space osteogenesis under the sinus floor after elevation of the sinus floor / 口腔疾病防治

@#With the continuous development of maxillary sinus floor elevation technology, the osteogenesis mechanism of maxillary sinus floor elevation has always been a concern of scholars. The membrane of the maxillary sinus is an indispensable physiological structure in the process of space osteogenesis under the sinus floor after elevation of the sinus floor. In recent years, the role of the maxillary sinus floor mucosa in sinus floor space osteogenesis has been a research hotspot. Recent studies have found that the maxillary sinus floor membrane plays a role as a natural biological barrier membrane in the process of sinus floor space osteogenesis after maxillary sinus floor elevation; in addition, it has the ability to undergo osteogenesis. It has also been found that maxillary sinus membrane stem cells (MSMSCs) derived from the maxillary sinus floor membrane have characteristics of mesenchymal stem cells, which can differentiate into osteoblasts and participate in sinus floor space osteogenesis after maxillary sinus floor elevation. New studies have also found that small RNAs such as microRNAs, long noncoding RNAs and circular RNAs can regulate the osteogenic differentiation of MSMSCs, which may be important biological targets for promoting osteogenesis in the sinus floor space. In this paper, the relationship between the maxillary sinus floor mucosa and bone formation after maxillary sinus floor elevation, the barrier and osteogenic function of the maxillary sinus floor mucosa, the sources of osteoblasts involved in osteogenesis of the sinus floor space, and the molecular regulatory mechanisms of stem cells derived from maxillary sinus mucosa will be elucidated step by step.

Clinical guidelines for maxillary sinus floor elevation with sinus membrane lesions / 口腔疾病防治

@#Maxillary sinus membrane lesions have been broadly detected before implant surgery in the posterior maxilla region, resulting in uncertainty regarding maxillary sinus floor elevation surgery. In this context, we composed this commentary article based on the current literature and the clinical experience of our department. We discuss the common lesion types shown by CBCT including membrane pathological thickening, polyps/cystic lesions and air-liquid level in the sinus. Maxillary sinus floor elevation surgery can be conducted in patients with membrane thickening of 2-5 mm or with polyps/cysts of less than half of the sinus height (because the above symptoms have little influence on the outcome of surgery). Membrane thickening of more than 5 mm with ostium obstruction, antrochoanalpolyps, mucoceles and cysts of more than half of the sinus height should be carefully treated. Different treatments can be performed such as conducting elevation surgery while retaining the cyst, removing the cyst before surgery or removing the cyst during surgery based on the cyst type and size, inflammation, patency of the ostium, etc. Antibiotics-anti-inflammatory-aspiration, surgical debridement and oral lesions eliminations are generally used for treating post-operative sinusitis. Presurgical radiographic evaluation is the key to diagnosing and treating these membrane lesions. We highly advocate collaboration between our dentists and otolaryngologists on this issue.

Short-term and mid-term follow-up study of 34 cases of maxillary posterior teeth deletion treated by orthotopic implantation combined with maxillary sinus floor elevation at the same time / 中国基层医药

Objective To investigate the application value and short-term and mid-term prognosis of orthotopic implantation combined with maxillary sinus floor elevation in the treatment of patients with maxillary posterior teeth deletion at the same time.Methods A total of 68 patients with maxillary posterior teeth deletion in the Integrated Traditional Chinese and Western Medicine Hospital of Shanxi Province from June 2014 to June 2016 were selected and randomly divided into the control group(n=34)and the study group(n=34)according to the digital table.The control group was treated with dental implant technology to repair,and the study group was treated with implanted orthotopic implantation combined with maxillary sinus floor elevation at the same time.The follow-up was continued for 3-12 months after operation.The degree of postoperative pain,the incidence of complications,the satisfaction of the treatment,and the prognosis of the two groups after 12 months of operation(the exfoliation of implant and the loosening of the implant)were statistically analyzed.Results The good rate of pain in the study group was 97.06％(33/34),which was higher than that of the control group [76.47％(26/34)](P<0.05).There was no statistically significant difference in the incidence rate of complications between the study group [5.88％(2/34)]and control group[8.82％(3/34)](P>0.05).The treatment satisfaction of the study group [97.06％(33/34)] was higher than that of the control group [70.59％(24/34)](χ2 =8.758,P<0.05).The incidence rate of poor prognosis of the study group[2.94％(1/34)]was lower than that of the control group [23.53％(8/34)](χ2 =4.610,P <0.05).Conclusion Orthotopic implantation combined with maxillary sinus floor elevation in the treatment of patients with maxillary posterior teeth deletion at the same time has less postoperative pain and high treatment satisfaction.And the complications and incidence of exfoliation and loosening of implants are low after 12 months of operation.

Research progress in maxillary sinus mucosal disease associated with maxillary sinus floor lifting / 中华口腔医学杂志

Maxillary sinus augmentation is an effective procedure to gain bone height for implant placement in an atrophic posterior maxilla. But maxillary sinus diseases are prevalent in patients scheduled for sinus lift procedures. The presence of these diseases may increase the difficulties in performing the surgery and the risk of developing postoperative complications. This paper summarizes and introduces the common maxillary sinus mucosa diseases related to maxillary sinus augmentation.

Clinical evaluation of two transalveolar methods for sinus augmentation with placing 1 204 implants immediately / 中华口腔医学杂志

Objective@#To compare the clinical outcomes of posterior maxillary implant surgery when using the regular transalveolar approach or with the crestal approach-sinus (CAS-KIT), a device for maxillary sinus membrane elevation by the crestal approach using a special drilling system and hydraulic pressure.@*Methods@#In this retrospective study 887 patients during Jan 2012 to July 2015 in Hangzhou Dental Hospital with underwent either regular transalveolar approach or CAS-KIT approach for maxillary augmentation; whereas 11 patients dropped out for the reason of serious membrane perforations. Totally, 876 patients with 1 204 plants, placed immediately after transalveolar maxillary augmentation, were included in this study. The data analysis was performed by radiological measures to assess the changes in height of maxillary sinus floor after the transalveolar augmentation at different time points. In addition, the complications after surgery, failure rates, osseointegration condition and the performance of rehabilitation were evaluated as well.@*Results@#Five hundred and three patients were experienced with regular transalveolar approach, and 7 patients were drop out for the serious membrane perforations. Thus, 496 patients received 653 implants in this group; the average lifted range in maxillary sinus floor height changes was (4.08±3.45) mm. The complications were minor membrane perforations during procedure in 64 patients, postoperative maxillary sinus infection happening in 2 patients and 13 patients experienced rehabilitation failure. Three hundred and eighty-four patients had CAS-KIT approach with 4 patients dropped out. Three hundred and eighty patients get 551 implants with the mean lifted range of (8.36±4.07) mm in maxillary sinus floor height changes. Minor membrane perforations during procedure occurred in 31 people and 2 got postoperative maxillary sinus infection. The 4 year overall survival rate of 1 204 implants was 97.26%, with four implants fell off after 3 months of rehabilitation and one implant occurred after one year of rehabilitation.@*Conclusions@#The regular transalveolar sinus lift technique is easier and time saving, but the compromised lifting range in maxillary sinus floor height and the comparatively high occurrence of intraoperative membrane perforations should be concerned. Using CAS-KIT could be an alternative method to perform maxillary sinus augmentation with a reduced incidence of complications. There was no statistically difference in implant failure rates and incidence of postoperative maxillary sinus infection between two groups.

Maxillary sinus floor elevation / 口腔疾病防治

@#Maxillary sinus floor elevation is a common method to increase the bone height in posterior maxilla. Maxillary sinus floor elevation can be divided into 2 types: sinus floor elevation with lateral window approach and sinus floor elevation with trans-alveolar approach. The present article reported the anatomy, antibiotics choice, indications, grafting, growth factors, complications and the influence of tobacco on maxillary sinus floor elevation.

Presencia y distribución de tabiques intrasinusales en el piso del seno maxilar / Prescence and distribution of intrasinusal septa in the maxillary sinus floor

La pérdida de dientes superiores causa reabsorción del proceso alveolar y la neumatización del seno maxilar. La implantología oral ha permitido solucionar la perdida de dientes, sin embargo, cuando existe neumatización del seno maxilar, la disponibilidad ósea se ve disminuida, dificultando el procedimiento implantologico. Para remediar esta situación se efectúa la técnica quirúrgica de levantamiento del piso del seno maxilar, la que puede tener complicaciones por la morfología interna del seno, específicamente por la presencia de septos intrasinusales. El objetivo de este estudio es verificar la presencia y distribución de los septos intrasinusales, debido a su importancia en técnicas quirúrgicas realizadas en implantología oral. Se realizó un estudio descriptivo, basado en el análisis visual de huesos maxilares aislados. De 65 huesos se seleccionaron 51 (42 dentados y 9 edéntulos) que cumplían con determinados criterios de inclusión. La segunda parte del estudio consistió en dividir topográficamente el piso del seno en tres regiones: anterior a la cresta cigomato alveolar, en relación a ella, y posterior a la cresta. La observación de los septos fue realizado por un único examinador, asistido por un dispositivo USB, con 4 leds de alta luminiscencia. De los 51 maxilares analizados se obtuvo: 74,5 por ciento, presentaron al menos un septo intrasinusal, 25,4 por ciento, no presentaron septos visibles. Los maxilares que presentaron un único tabique correspondieron al 33,3 por ciento de la muestra, el 19,6 por ciento de la muestra presento sólo dos tabiques, el 15,7 por ciento presentó tres tabiques, mientras que los maxilares que presentaron más de tres tabiques intrasinusales correspondieron sólo al 5,9 por ciento. Del total de tabiques encontrados (75 tabiques) el 42 por ciento se observó en la región anterior, 21 por ciento en la región de la cresta cigomato alveolar y el 37 por ciento en la región posterior del seno maxilar. De los 42 maxilares en condición...

The loss of upper teeth causes alveolar process resorption and maxilary sinus pneumatization. Oral implantology has solved these losses, however, when pneumatization of the maxillary sinus exists, bone availability is diminished, difficulting implantology procedure. To remedy this situation, the surgical technique of lifting the maxillary sinus floor is indicated, which can have complications because of the internal maxillary sinus morphology, specifically the presence of intrasinusal septa. The aim of this study is to verify the presence and distribution of intrasinusal septa, due to its importance in surgical techniques performed in oral implantology. We conducted a descriptive study, based on visual analysis of isolated maxilary bones. Of 65 bones, 51 (42 dentate and 9 edentulous)were selected that met certain inclusion criteria. The second part of the study was, to divide the sinus floor topographically into three regions: anterior to the zygomatic alveolar crest, in relation to it, and posterior to the crest. The observation of the septa was performed by a single examiner, assisted by a USB device with 4 high-luminance LEDs. Of the 51 maxillary analyzed obtained: 74.5 percent had at least one intrasinusal septum, 25.4 percent showed no visible septa. The maxilary bones that had a single septum corresponded to 33.3 percent of the sample, 19.6 percent of the sample had only two septa, 15.7 percent had three septa, while the maxillary bones that had more than three intrasinusal septa corresponded only to 5.9 percent. Of all septa found (75 septa) 42 percent was observed in the anterior region, 21 percent in the region of the zygomatic crest and 37 percent in the posterior region of the maxillary sinus. Of the 42 dentate maxillary bones in 88,1 percent present intrasinusal septa, while the total edentulous maxillary bones (9) only 11 percent present intrasinusal septa. This study establishes that a significant portion of the maxillary bones have...

Maxillary sinus floor elevation using autogenous skin-derived mesenchymal stem cells in miniature pigs

INTRODUCTION: In our previous studies, we isolated porcine skin-derived mesenchymal stem cells (pSDMSCs) from the ears of adult miniature pigs and evaluated the pluripotency of these pSDMSCs based on expressions of transcription factors, such as Oct-4, Sox-2, and Nanog. Moreover, the characteristic of mesenchymal stem cells was revealed by the expression of various mesenchymal stem cell markers, including CD29, CD44, CD90, and vimentin. The aim of this study was to evaluate in vivo osteogenesis after maxillary sinus lift procedures with autogenous pSDMSCs and scaffold. MATERIALS AND METHODS: The autogenous pSDMSCs were isolated from the 4 miniature pigs, and cultured to 3rd passage with same methods of our previous studies. After cell membranes were labeled using a PKH26, 1x10(7) cells/100 microliter of autogenous pSDMSCs were grafted into the maxillary sinus with a demineralized bone matrix (DBM) and fibrin glue scaffold. In the contralateral control side, only a scaffold was grafted, without SDMSCs. After two animals each were euthanized at 2 and 4 weeks after grafting, the in vivo osteogenesis was evaluated with histolomorphometric and osteocalcin immunohistochemical studies. RESULTS: In vivo PKH26 expression was detected in all specimens at 2 and 4 weeks after grafting. Trabecular bone formation and osteocalcin expression were more pronounced around the grafted materials in the autogenous pSDMSCs-grafted group compared to the control group. Newly generated bone was observed growing from the periphery to the center of the grafted material. CONCLUSION: The results of the present study suggest that autogenous skin-derived mesenchymal stem cells grafting with a DBM and fibrin glue scaffold can be a predictable method in the maxillary sinus floor elevation technique for implant surgery.