Sinus Membrane Research Articles

Endodontic sealer-induced maxillary sinusitis: intraoral surgical approach and implant placement at a site of failed nasal endoscopic surgeries.

A 28-year-oldmale patientwas referred from an otorhinolaryngologist for managing unilateral chronic maxillary sinusitis (MS). The patient had undergone two functional endoscopic sinus surgeries (FESS), although the MS was not resolved. Based on his dental history, endodontic treatment had been done on the symptomatic area. A leak of endodontic sealer and peri-apical lesion on tooth #14 was found on cone-beam computed tomographic examination. Extraction of tooth #14 and the modified Caldwell-Luc operation were performed to remove the endodontic sealer material and relevant inflammatory tissue. The sinus membrane lining was maintained as much as possible during the surgery. Implant placement was performed on the tooth extraction site. All clinical symptoms disappeared after the surgery. Radiographic and endoscopic examination revealed successful osseointegration of the implant and complete resolution of the MS. FESS alone may not be sufficient to treat MS derived from dental origin. For unilateral MS, dental history should be carefully checked.

Does the Protrusion of Corticobasal Implants in the Maxillary Sinuses Affect Sinus Health? A Retrospective Study.

The aim of this retrospective study is to investigate the effect of corticobasal implant penetration in the nasal and maxillary sinuses on sinus health and implant survival rate in cases of severely atrophid ridges. This retrospective study was conducted on thirty patients with 172 implants who underwent corticobasal implant treatment between 2014 and 2018. Implants were divided into two groups according to the penetration depths (Group A, <4 mm; Group B, 4 mm). Inclusion criteria for the study included: (A) patients with severe maxillary ridge resorption with an immediately loaded corticobasal implant-supported prosthesis that showed implant protrusion inside the maxillary sinus on cone-beam computed tomography (CBCT); and (B) patients with a preoperative and postoperative follow-up CBCT scan using the same standard technique and machine. (C) Patients without any history of sinusitis before implant insertion patients who fulfilled the inclusion criteria were recalled for follow-up. The presence of sinus complications was clinically assessed according to the clinical practice guidelines for adult sinusitis of the American Academy of Otolaryngology-Head and Neck Surgery and Radiologically using CBCT. Moreover, patient satisfaction was evaluated using yes-or-no questions. The result was statistically analyzed using Fisher's Exact test. Despite the differences in implant penetration depths, no clinical signs of sinusitis were evident in any patient. One patient presented with transient epistaxis after the surgery, and 2 patients with nine implants revealed nonsignificant thickening of the sinus membrane radiologically (p = 0.055). All implants showed optimum bone-implant contact with a 100% survival rate. A significant relationship was reported between the thickness of the membrane and the patient's gender, hypertension, and smoking habits. (p = 0.001*, p = 0.002*, and p = 0.034*, respectively). Penetration of corticobasal implants in the maxillary sinus did not compromise the health of the maxillary sinus or implant survival rate. Limited posterior maxillary bony support and maxillary sinus pneumatization present challenges in implant dentistry and increase the possibility of implant protrusion inside the maxillary and nasal cavities. Hence, studying the effect of this protrusion on the maxillary sinuses' health and implant survival is highly significant.

Maxillary sinus membrane elevation and coagulum compared with maxillary sinus floor augmentation and a composite graft: A 1-year single-blinded randomized controlled trial.

The aim was to evaluate the 1-year implant outcome and patient-related outcome measures (PROMs) after maxillary sinus membrane elevation and coagulum (test) compared with maxillary sinus floor augmentation and a 1:1 ratio of autogenous bone graft from the buccal antrostomy and deproteinised porcine bone mineral (DPBM) (control). Forty patients (30 female, 10 male) with a mean age of 50 years (range 25-71 years) and an alveolar ridge height between 4 and 7 mm were randomly allocated to test or control. Outcome measures included survival of suprastructures and implants, implant stability quotient, health status of the peri-implant tissue, peri-implant marginal bone loss, frequency of complications and PROMs using Oral Health Impact Profile-14 combined with questionnaires assessing patient's perception of the peri-implant soft tissue, implant crown, function of the implant, and total implant treatment outcome using visual analogue scale. Mean differences were expressed with standard deviation and 95% confidence interval. Level of significance was 0.05. All suprastructures and implants were well-functioning after 1-year of functional implant loading. No significant difference in any of the applied outcome measures was observed between test and control. Both treatments revealed high patient satisfaction scores and significant improvement in oral health-related quality of life. There were no significant differences in implant outcome and PROMs between test and control, after 1-year of functional implant loading. Neither of the treatments can therefore be considered better than the other. Thus, long-term randomized controlled trials are needed before definitive conclusions can be provided about the two treatment modalities.

Cone-beam computed tomographic analysis of maxillary sinus septa among Yemeni population: a cross-sectional study

BackgroundMaxillary sinus septa increase perforation risk of Schneiderian membrane during the sinus floor elevation (SFE). Cone Beam Computed Tomography (CBCT) allows for a more precise assessment of the septal position; thus, preoperative CBCT analysis is substantial to avoid possible complications. This study aims to investigate the 3D characteristics of the maxillary sinus septa based on CBCT images. To our knowledge, no study reported the CBCT-based investigation for the sinus septa among Yemeni population.Materials and methodsThis is a retrospective cross-sectional analysis of 880 sinus CBCT images 440 patients. The septa prevalence, locations, orientations, morphology, and associated factors were analyzed. The effect of age, gender, and dental status on the sinus septa and the relationship between sinus membrane pathology and sinus septa were also analyzed. Anatomage (Invivo version 6) was used for CBCT images analysis. Descriptive and analytical statistics were performed, and a P-value < 0.05 was significantly considered.ResultsThe maxillary sinus septa were found among 63.9% of patients and 47% of sinuses. The average septa height was 5.2 mm. 15.7% of patients had septa in the right maxilla, 18% in the left, and 30.2% in both. Gender, age, and dental condition had no influence on the presence of septa, and septa presence did not influence sinus membrane pathology. Many septa originated from the floor (54.5%), located in the middle (43%), with coronal orientation (66%) and complete configuration (58.2%).ConclusionBased on our findings, the septa prevalence, locations, orientations, and morphology were significant and equivalent to the highest recorded in the literature yet. Thus, when sinus floor elevation is planned, CBCT imaging of the maxillary sinus is recommended for safe dental implantation.

The Impact of Sinus Floor Elevation Techniques on Sinus Membrane Perforation: A Systematic Review and Network Meta-analysis.

Purpose: To compare the risk of sinus membrane perforation (SMP) among lateral window sinus floor elevation (LSFE) and transcrestal sinus floor elevation (TSFE) techniques in prospective and retrospective studies for patients who underwent sinus augmentation for dental implant placement. Materials and Methods: A database search was conducted to screen the literature published from January 1960 to August 2021. The associations between SMP and surgical techniques as well as other clinical factors were evaluated via network meta-analysis. The impact of SMP on vertical ridge gain and implant survival was also evaluated. Results: Eighty-five studies with 5,551 SFE procedures were included. In LSFE techniques, using rotary burs showed the highest risk of SMP (surface under the cumulative ranking area [SUCRA] = 0.0745). In TSFE techniques, using reamers had the lowest risk of SMP (SUCRA = 0.9444). Increased SMP prevalence was significantly associated with reduced implant survival rate (odds ratio [OR] = 0.45 per 10% increase of SMP rate [95% credible interval (CreI): 0.21, 0.71], P < .001). Conclusions: With the inherent limitations, this network meta-analysis suggested that some techniques within either the LSFE or TSFE group may reduce SMP risk. Additional randomized controlled trials and better assessment of SMP are required to directly compare the risk of SMP between LSFE and TSFE.

Increased risks of maxillary sinus mucosal thickening in Chinese patients with periapical lesions

ObjectivesThis study aimed to evaluate the effects of factors related to periapical lesions (PALs) on sinus membrane thickening (SMT) in the Chinese population using cone-beam computed tomography (CBCT). MethodsIn this retrospective study, CBCT images (n = 512) of maxillary sinuses of 446 patients were evaluated by two examiners for SMT and PALs, PAL size, and the distance between the maxillary sinus floor (MSF), and the PAL’s edge/root apex. The data were analyzed using analysis of variance, the Kruskal-Wallis test, χ2-test, and logistic regression. ResultsA binary logistic regression model showed that the prevalence and severity of SMT > 2 mm were significantly associated with older age (>60 years) (odds ratio [OR]: 4.03, 95% confidence interval [CI]): 2.24–7.72, P < 0.001], male sex (OR: 2.08, 95% CI: 1.21–3.56, P < 0.006), and PALs (OR: 6.89, 95% CI: 3.93–12.08, P < 0.001). The type of contact and penetration between the MSF and PALs or root apex showed a more significant relation with SMT > 2 mm than did distance after adjusting for confounding factors, including age and sex (PALs: OR = 10.17 and 14.57, P < 0.001; root apex: OR = 3.49 and 5.86, P < 0.001). ConclusionsThe prevalence and severity of SMT were significantly associated with older age, male sex, PALs, PAL size, and the distance between the MSF and PALs/root apex. Therefore, communication between dental surgeons and an otolaryngology specialist is important for the timely diagnosis and treatment of SMT of dental origin.

A systematic review of sinus floor augmentation complications. Does graft type influence the complications rate?

Background. Sinus floor elevation is considered a safe procedure to properly augment the height of the edentulous crest. Often, complications may arise due to multiple causes and can lead to a poor outcome of the graft and implant’s osseointegration. A careful surgical approach, a good knowledge of possible obstacles, and careful treatment planning can reduce the risks of complications, as well as their impact on the surgical outcome. This study aims to make a literature review of 40 articles, analyzing the incidence and type of complications related to maxillary sinus graft surgeries and graft materials. Material and methods. A total of 40 articles published between 2015 and 2021 were selected for a systematic literature review on maxillary sinus floor complications. The studies were selected from 2 different internet databases: PubMed and Science Direct. The sinus lift complications were counted and their incidence was organized upon the surgical technique and the timing of occurrence (intraoperative, postoperative). It was also analyzed if the graft material influences the complication rate. Results. In a group of 1757 sinus augmentation surgeries performed on 1605 patients, 363 complications were found. Sinus membrane perforation occurred in 242 cases, 29 procedures resulted in partial or total graft loss, there were 26 postoperative cases of sinusitis, 24 sinus infections, 16 wound dehiscence, 6 bleeding complications, 5 lost implants, and 2 oro-antral fistulas. Conclusion. Sinus lift complications are sometimes inherent circumstances of the procedures, but they can also be prevented through an accurate technique and preoperative plan. The type of bone graft does not influence the incidence of surgical complications.

Application of titanium 3D-printed double-sleeve guide for zygomatic implants: A technique report.

The unique anatomical structure of the atrophic edentulous maxilla limits the placement of endosteal root form dental implants without bone grafting and augmentation. Surgical placement of zygomatic implants in an optimal position remains challenging. This technique report illustrates a novel digital guide technology, including the design workflow, application method, and indications for assisting with the placement of zygomatic implants using a bone-supported titanium double-sleeve guide. In addition, when the implant body reaches the zygomatic bone following an intra-sinus path, including ZAGA type 0 and ZAGA type 1 cases, a matching window osteotomy surgical guide is used to locate the lateral window boundary and protect the sinus membrane. With this technique, the surgical procedure is simplified, and the precision of guided zygomatic implant placement is improved.

Lateral sinus floor elevation with simultaneous mucosal cysts management

Introduction. Specialists in the field often face uncertainty in deciding whether to perform sinus lifting surgery in the presence of a mucosal cyst during the pre-implantation preparation of patients with maxillary sinus pathology. While some specialists believe that the sinus lifting operation cannot be performed in the presence of sinus pathology and should be resorted to after a long period of healing, others believe that it can be performed in the presence of sinus pathology or simultaneously with sinus sanitation. As a result, there are more controversies about the treatment tactics, stages, and timing required to achieve the rehabilitation of these patients, demonstrating the significance of the problem at hand. Materials and methods. The study included twenty patients who were referred to the Department of OMF Surgery and Oral Implantology “Arsenie Guţan” and the dental clinic “OmniDent” between 20.06.2016 and 01.01.2019 for implant-prosthetic rehabilitation due to partial edentulism in the upper jaw in the lateral area and the presence of a mucosal cyst in the maxillary sinus. The first group comprised of seven patients in whom the mucosal cyst was completely removed while simultaneously undergoing lateral sinus lifting. The second group consisted of five patients, aged between 18 and 67 years (average 45 years), who underwent marsupialization of the mucosal cyst. The third group comprised of six patients in whom the cyst content was only aspirated, without removal or marsupialization of the cyst. Results. All three methods were found to be effective, although total perforations of the sinus mucosa were recorded in the first two groups, preventing the performance of sinus lifting at that stage. The method of aspirating the cystic content, however, is a simple and low-risk procedure that does not carry the risk of perforating the sinus membrane and provides predictable results. Conclusions. The mucosal cyst does not present a contraindication to sinus lifting but requires additional surgical procedures.

Chronic sinusitis diagnosis and treatment

The growing popularity and use of endoscopic surgery in the field of otolaryngology prompts an attempt to organize knowledge about possible methods of surgery in the nasal cavity and paranasal sinuses. Chronic sinusitis is an inflammatory process involving the mucous membrane of the paranasal sinuses, lasting more than 12 weeks. The system of fissures in the lateral wall of the nasal cavity is an ostiomal ductal complex, the obstruction of which is the direct cause of chronic inflammation of the paranasal sinuses. FESS is a modern method in which access to the paranasal sinuses is obtained through the nasal cavity. The aim of the procedure is to widen, above all, too narrow sections of the middle meatus and the orifice-ductal complex. Compared to traditional methods, it is less invasive, allows you to regain the proper function of the maxillary sinus and, moreover, allows you to correct a deviated nasal septum, remove or reduce overgrown turbinates during one operation using the same access. Although traditional methods of surgery are still used in some groups of patients, modern minimally invasive endoscopic surgery strongly limits their use and becomes the method of first choice. Method: The literature was reviewed using the Pub med search engine and Google scholar using the words: Chronic nasal sinusitis, reasons of chronic nasal sinusitis, FESS, acute nasal sinusitis, nasal sinusitis radiology.

Combination of a surgical template and a collagen strip for guiding sinus floor elevation in the oblique sinus floor: A technical note

Sinus floor elevation (SFE) by transcrestal approach has been proven to be a predictable and minimally invasive treatment that augments posterior maxilla with insufficient bone height, allowing the prosthetic rehabilitation of this area with dental implants. However, precise and sufficient elevation of the Schneiderian membrane without perforation is challenging through this blind technique especially in the presence of anatomical restrictions. This note describes a novel technique combining a surgical template and an absorbable collagen sponge (ACS) strip for transcrestal SFE in the oblique sinus floor. A surgical template was used to locate the oblique sinus floor and a collagen strip was placed to orient membrane elevation, meanwhile, protect the sinus membrane. Within the limits of present observation, this technique may increase the manipuility while reducing the risk of complications.

Comparison between Platelet-rich Fibrin and Saline Filling after Sinus Elevation without Adjunctive Bone Graft in Dental Implants Insertion Using CBCT.

The goal of this research was to compare radiographically the outcomes of hydraulic transcrestal sinus lifting with platelet-rich fibrin (PRF) or normal saline filling on implant survival rates, negative outcomes, and variations in the height of residual alveolar ridge (HARB). There were 80 study participants included and 90 dental implants were placed. The study participants were divided into two categories: Category A and Category B. Each category consists of 40 study participants. Category A: Normal saline was placed in the maxillary sinus. Category B: PRF was placed in the maxillary sinus. Implant survival, complications, and HARB alterations were the outcome metrics. Radiographic images through Cone-beam computed tomography (CBCT) were retrieved and compared prior to surgery (T0), immediately following surgery (T1), three months later (T2), 6 months later (T3), and 12 months later (T4). There are 90 implants having an average length of 10.5 ± 0.7 mm were inserted into the posterior portion of the maxilla of 80 patients with an average HARB of 6.9 ± 1.2 mm. At T1, elevation in HARB peaked, and the sinus membrane continued to droop but steadied while observed at T3. The steady increment of areas of radiopacities was noticed below the elevated membrane of the maxillary antrum. A radiographic intrasinus bone increase of 2.9 ± 1.4 mm was caused by the PRF filling, compared to 1.8 ± 1.1 mm by the saline filling at T4 (p < 0.05). Over the course of the one-year follow-up period, all of the implants were operating normally with no major issues. Platelet-rich fibrin when used as a filling medium alone without bone graft can cause significant ascend in height of the residual alveolar bone (HRAB). The degradation of the alveolar bone under the maxillary sinus following tooth loss frequently restricts the placement of the implant in the edentulous region of posterior maxilla. Numerous sinus-lifting surgery procedures and tools have been developed to address these problems. It has been a topic of debate regarding the benefits of bone grafts placed at the apical region of the implant. The sharp protrusions of the granules of bone graft may also provide a danger of membrane puncture. Recently, it was shown that regular bone gain might occur inside the maxillary antrum without the use of any bone transplant material. Additionally, if there were substances that filled the gap between the floor of the sinus and the raised sinus membrane, then the membrane of the maxillary sinus could be raised greater and for a longer period of time during the phase of formation of new bone formation.

Evaluation of Two Configurations of Hydroxyapatite and Beta-Tricalcium Phosphate in Sinus Grafts with Simultaneous Implant Installation: An Experimental Study in Rabbits.

This study aimed to evaluate peri-implant bone formation in rabbits after sinus grafting mediated by hydroxyapatite and beta-tricalcium phosphate (HA + β-TCP) in granule or paste configurations, concomitant with immediate implant installation. Thirty-four rabbit maxillary sinuses were grafted with HA + β-TCP, half of which were applied in a granule and half in a paste composition. Implant placement was performed simultaneously. At 7 and 40 days postoperatively, the animals were euthanized, and samples were prepared for tomographic, microtomographic, histological, histometric (hematoxylin and eosin staining, HE), and immunohistochemical (labeling of transcription factor Runx-2 [RUNX2], vascular endothelial growth factor [VEGF], osteocalcin [OCN], and tartrate-resistant acid phosphatase [TRAP]) analysis. Implant removal torque was also measured. On tomography, maintenance of sinus membrane integrity was observed in both the groups. Higher values of morphometric parameters evaluated by micro-CT were found in the "paste group" after seven days. At 40 days, there were no significant differences between the groups in most of the microtomographic parameters evaluated. In histological sections stained with HE, a higher percentage of newly formed bone was observed in the "granule group" after 40 days. Similar positive immunolabeling was observed for both RUNX2 and OCN in both the experimental groups. TRAP immunolabeling was similar in both groups as well. VEGF labeling increased in the "granule group", indicating a higher osteoconductive potential in this biomaterial. Similar removal torque values were observed in both groups. Thus, the two HA + β-TCP configurations showed similar healing patterns of simultaneously installed implants adjacent to sinus floor elevation. However, significantly higher bone values were observed for the "granule configuration". The HA + β-TCP granules and paste presentations showed favorable long-term healing results, with bone formation in similar quantities and quality adjacent to the implants.

Efficacy of Two Different Hydrodynamic Sinus Lift Systems for Atraumatic Elevation in Immediate Implant Placement.

To evaluate the efficacy of two hydrodynamic sinus lifting procedures and to successfully place immediate implants in maxillary posterior sites that have a compromised native bone as a result of periodontal or endodontic disease. A total of 26 patient sites were enrolled with 13 sites each in the Minimally Invasive Antral Membrane Balloon Elevation (MIAMBE) and Drill Integrated Hydrodynamics for the transcrestal sinus floor elevation (DIHSFE) groups who received transcrestal sinus floor elevation followed by immediate implant placement. Clinical parameters such as sinus membrane perforations, nasal bleeding, postoperative sinusitis, VAS scores at Day-7 for pain and discomfort, primary implant stability and time taken were evaluated. The DIHSFE had greater sinus membrane perforations and incidence of nasal bleeding when compared with MIAMBE with (p = 0.066) and (p = 0.141). Post-operative sinusitis was evident in both the groups with (p = 0.619). The mean VAS score was statistically significant between both the groups (p ≤ 0.005). The insertion torque values, and mean time taken for surgical procedure was not statistically significant between groups. The present study highlighted that MIAMBE is superior to DIHSFE in its ability to cause less severe patient morbidities and post-operative complications.

No title.

It is of interest to compare the treatment modalities of sinus membrane thickening, by analyzing the difference in pre and post-intervention radiographic measurement of sinus membrane thickness. Results showed that combination therapy of steam and mucolytics decreased the sinus thickening in a statistically significant manner compared to mucolytics alone. Thus, there is a correlation between maxillary sinus membrane thickening and patency of maxillary ostium radiographically.

EVALUATION OF THE EFFECTIVENESS OF DIFFERENT METHODS SINUS FLOOR ELEVATION THE LATERAL APPROACH

Background: The posterior maxillary area sometimes has insufficient bone mass for dental implants. The augmentation of the sinus floor allows the implant to be placed in the posterior of the upper jaw. Purpose: The aim of this study was to compare the effectiveness antral balloon- assisted maxillary sinus elevation and traditional sinus floor elevation followed by bone graft and delayed implant placement the posterior maxillary area. Material and methods: A total of 68 patients, (aged 27 to 56 years, 32 women and 36 men), without any systemic diseases with unilateral/bilateral missing teeth and atrophy of the posterior maxillary area, who required an enlargement of the sinus prior to implant placement, whom the location of the sinus floor from the crest was 3-5mm, width ≥5 mm were included in the study between 2018 and 2021. Patients underwent a thorough clinical examination according to the generally accepted scheme. All patients were selected after meticulous evaluation of their medical histories and dental examinations, including OPG and dental Computed Tomography (CT) scans. Results: The sinus lift using balloon technique was performed successfully in patients 1 group, with no complications. In 9 patients 2 group, perforation of the sinus membrane occurred during the operation, sinusitis in 4 patients, graft failure in 3 patients. Regardless of the approach used, both approaches showed significant increases in bone mass gain. Though not statistically significant difference, balloon-assisted procedure showed more mean bone gain (8.4 mm) compared to osteotome -assisted procedure (8.1 mm). The mean amount of Marginal Bone Loss (MBL) in patients 1 group 3 years follow-up was 0.86 mm in patients 2 group showed significantly less marginal bone loss 1,16mm. The implant survival rate 3 years follow-up was in patients 1 group was 97.62%, in patients 2 groups was 95.2%. Conclusions: Research has shown that the balloon sinus lifting offers predictable, safe and effective results, and eliminates the complications associated with traditional side window techniques. However, further controlled clinical trials are needed to evaluate the efficacy and safety of these technique for their appropriate implementation in the field of oral implanotology.

A New Simplified Autogenous Sinus Lift Technique.

Oral maxillofacial rehabilitation of the atrophic maxilla with or without pneumatization of the maxillary sinuses routinely presents limited bone availability. This indicates the need for vertical and horizontal bone augmentation. The standard and most used technique is maxillary sinus augmentation using distinct techniques. These techniques may or may not rupture the sinus membrane. Rupture of the sinus membrane increases the risk of acute or chronic contamination of the graft, implant, and maxillary sinus. The surgical procedure for maxillary sinus autograft involves two stages: removal of the autograft and preparation of the bone site for the graft. A third stage is often added to place the osseointegrated implants. This is because it was not possible to do this at the same time as the graft surgery. A new bioactive kinetic screw (BKS) bone implant model is presented that simplifies and effectively performs autogenous grafting, sinus augmentation, and implant fixation in a single step. In the absence of a minimum vertical bone height of 4 mm in the region to be implanted, an additional surgical procedure is performed to harvest bone from the retro-molar trigone region of the mandible to provide additional bone. The feasibility and simplicity of the proposed technique were demonstrated in experimental studies in synthetic maxillary bone and sinus. A digital torque meter was used to measure MIT and MRT during implant insertion and removal. The amount of bone graft was determined by weighing the bone material collected by the new BKS implant. The technique proposed here demonstrated the benefits and limitations of the new BKS implant for maxillary sinus augmentation and installation of dental implants simultaneously.

Modified internal sinus elevation for patients with low residual bone height: A retrospective clinical study.

We have modified the internal sinus elevation by combining it with the sinus mucoperiosteum stripping procedure, which further increases the indications for the internal lift. Similar long-term clinical follow-up studies and three-dimensional finite element analyses are rare. This study aimed to investigate the feasibility of the modified internal sinus floor elevation method in patients with low residual bone height using a three-dimensional (3D) finite element model and report on the long-term outcomes. Overall, 99 implants were placed in 86 patients. All patients were followed-up for 3-24 months. The modified internal sinus floor elevation was dynamically simulated using a 3D finite element model, and the stress of the sinus membrane was measured. In trial group A (modified internal sinus floor elevation group), 57 implants were placed in 52 patients. The sinus floor height was lifted by 6.5 mm (95%confidence interval (CI): 6.2-6.8). The perforation rate was 8.8%, and the implant survival rate was 96.5%. In control group B (external sinus floor elevation group), 42 implants were placed in 34 patients. The sinus floor height was lifted by 8.8 mm (95%CI: 8.4-9.3). The perforation rate was 14.3%, and the implant survival rate was 100%. In trial group A, compared with the control group B, perforation decreased by 5.5% (odds ratio = 0.50 and 95%CI: 0.14-1.78; p = 0.282), and the sinus floor lift height was 2.3 mm lower (95%CI, 1.8-2.9; p < 0.001). The finite element analysis showed that the peak stress of the sinus membrane increased with an increase in height elevation and degree of membrane separation. Our findings indicate the positive clinical outcomes in patients with low RBH associated with the modified internal sinus elevation procedure.

Techniques of Maxillary Sinus Floor Elevation

Posterior maxillary region is often limited for standard implant placement because of reduced residual vertical bone height. An elevation of the maxillary sinus floor is one option in solving this problem. This article describes the various surgical techniques that can be used to enter the sinus cavity, elevating the sinus membrane and placing the bone grafts for placement of dental implants in the resorbed posterior maxillary region.

Cone Beam Computed Tomography Analysis of Posterior-Superior Alveolar Canal from a Fixed Reference Point: Implications for Sinus Floor Elevation Procedure through Lateral Approach.

Sinus floor elevation is commonly done in the maxillary posterior region prior to dental implant placement. This study primarily aimed at assessing the location of the posterior superior alveolar artery (PSAA) canal on cone beam computed tomography (CBCT) scans and its relation to the alveolar ridge and maxillary sinus from a fixed reference point. A total of 226 edentulous maxillary molar sites were included in this retrospective analysis. The distance from the PSAA to the sinus floor (SF), alveolar crest (AC) and a fixed reference point, that is, the roof of sinus (RS) were measured. The alveolar bone height (ABH), thickness of the crestal keratinized mucosa (CKM) and thickness of Schneiderian membrane (SM) were also evaluated. 54 sites (23.89%) were excluded from the study. The SF, AC, RS and ABH values averaged at 11.91mm ± 3.63mm, 16.05mm ± 3.96mm, 25.32mm ± 7.13mm and 4.93mm ± 4.27mm respectively. SF and AC was higher in second molar than first molar region (p < 0.001), but RS did not show significant difference (p = 0.85). CKM and SM averaged at 2.02mm ± 0.68mm and 1.31mm ± 0.81mm respectively. The PSAA can be visualized in CBCT scans with a prevalence of 76.11% and may not be detected when adherent to the sinus membrane. This study stresses on the need for a CBCT, prior to sinus surgeries through lateral approach, to assess the PSAA.