The influence of sinus membrane thickness upon membrane perforation during lateral window sinus augmentation

Risk factors contributing to membrane perforation in lateral window maxillary sinus elevation: systematic review and meta-analysis

OBJECTIVE

To scrutinize the risk factors related to membrane perforation during lateral window preparation for maxillary sinus elevation.

STUDY DESIGN

The investigation was conducted across different electronic databases, followed by a critical evaluation of studies that matched the inclusion criteria.

RESULTS

The studies identified several risk factors contributing to sinus membrane perforation. Thin membranes (<1.5 mm) are at significant risk of perforation compared to thicker ones. Smoking significantly increased the likelihood of perforation by 1.6 times, with one perforation occurring in every seven smokers treated. The presence of septa increased the risk of perforation three times compared to the absence of septa. There was a marginal significance (P = .05) that piezosurgery reduced the risk of perforation compared to rotary instruments. Limited evidence, based on three studies, indicated that the lateral wall thickness and the residual ridge height are significant factors for membrane perforation. The number of missing teeth and the window size did not appear to affect the likelihood of SMP.

CONCLUSIONS

Although most studies are retrospective, several factors are associated with membrane perforation during lateral window sinus preparation. Among all studied factors, membrane thickness, septa, and smoking appear to be the most prominent.

Anatomy of the Maxillary Sinus and the Role of CT Scans in Maxillary Sinus Augmentation Surgery

BACKGROUND

Detailed knowledge of sinus anatomy as well as timely identification through CT scans of the anatomic structures inherent to the maxillary sinus is required to avoid unnecessary surgical complications.

PURPOSE

To investigate sinus homeostasis, physiology, and anatomy; to review all anatomical-related risk factors for sinus membrane perforation; and to analyze the significance of preoperative and postoperative sinus CT scan imaging.

MATERIALS AND METHODS

Data from the recent literature on the above topics were explored.

RESULTS

Thinner membranes may not have sufficient mechanical strength to resist force during elevation or bone grafting, and thicker membranes may be associated with the presence of subclinical sinusitis. Increased thickness of an unhealthy membrane generally indicates a weaker membrane with a gelatinous texture, whereas thickening of a healthy membrane occurs at the periosteal layer level and can enhance its strength. Sinus membrane thickness, sinus septa, type of edentulism, and root position relative to the sinus cavity, residual bone height, sinus width, palatonasal recess angle, buccal wall thickness, zygomatic arch location, alveolar antral artery, and bone dehiscence may influence the clinical complexity of the surgery. There is no clear evidence of systematic negative outcomes related to sinus perforations. In patients with severely atrophic posterior maxillas, the possibility of lacerating the alveolar antral artery and/or detecting antral septa must be considered, especially when the residual ridge height is < 3 mm high. Transient edema and thickening of the sinus mucosal membrane typically resolve spontaneously. In cases of graft extrusion, conservative management could be considered for asymptomatic patients with healthy sinus and open ostium at the time of surgery. On the other hand, patients with symptoms should be referred. Radiographic evidence of implant protrusion into the sinuses is not always associated with complications.

CONCLUSIONS

Investigating sinus homeostasis and physiology, exploring the vascular anatomy within the maxillary sinus, identifying anatomical risk factors for sinus membrane perforation, and analyzing the significance of preoperative and postoperative sinus CT imaging provide a systematic and comprehensive framework for evaluating the complexity of maxillary sinus augmentation using a lateral approach.

Maxillary sinus augmentation via the bone lid technique: A prospective, radiographic case series

BACKGROUND

Maxillary sinus augmentation is one of the most performed procedures to increase the bone quantity of the atrophic maxilla to allow implant placement. The aim of the present case series was to describe a surgical protocol to perform maxillary sinus augmentation with the "bone lid technique," and its outcomes in a cohort of patients eligible for the procedure.

METHODS

After the initial clinical evaluation, a cone-beam computed tomography (CBCT) examination was performed for preoperative assessment. Patients were then scheduled for surgical intervention. At 6-9 months follow-up, patients underwent a second CBCT scan to evaluate bone height following bone graft and to schedule implant placement.

RESULTS

A total of 11 patients were enrolled in the study with a total of 13 sinus lift procedures. Membrane perforation was registered in 4 cases (30.76%). Mean surgical time was 67.69 min (SD 6.51). Postoperative period was uneventful in all patients, in the absence of complications. The mean graft volume increase was 2.46 cm3 (SD 0.85), and the mean height increase was 14.27 mm (SD 3.18). Mean membrane thickness was 1.40 mm (SD 0.75). In all the 4 cases with sinus membrane perforation, the membrane had a thickness lower than 1 mm.

CONCLUSIONS

The present study highlights that the maxillary sinus augmentation with bone lid repositioning could provide repeatable results in terms of bone height increase. The technique appears reliable both in terms of bone gain and absence of complications.

KEY POINTS

The bone lid technique for maxillary sinus augmentation provides repeatable results in terms of bone height increase. The favorable clinical outcomes can be related to an enhancement of bone formation due to the unique osteoconductive and osteoinductive properties of autogenous bone, along with a reduction of soft tissue ingrowth. Complications were not observed in any of the patients following the surgical procedures. The risk of Schneiderian membrane perforation is inversely proportional to membrane thickness; the thinner the membrane is, the higher the risk to perforate it.

Bone Regeneration After Sinus Floor Elevation in an Intact Sinus or a Sinus With Prior Large Membrane Perforation: A Preclinical Study Using a Rabbit Sinus Model

AIM

To determine bone regeneration following sinus floor elevation (SFE) at sites with or without prior sinus membrane perforation.

MATERIALS AND METHODS

The sinus membranes in the maxillary sinuses of 12 rabbits were intentionally perforated (≥ 5 mm) on one side, followed by application of a collagen matrix. SFE was performed on both sinuses after 8 weeks of healing, presenting two groups: SFE with a previous large sinus membrane perforation (group SFE_Perf), and in an intact sinus (group SFE). The animals were euthanized at 2 and 4 weeks after SFE. Micro-computed tomographic and histomorphometric analyses were performed.

RESULTS

The amount of newly formed bone within the augmented area did not differ significantly between the two groups at 2 weeks and 4 weeks (4.7 ± 1.0 mm2 vs. 5.3 ± 1.4 mm2 and 9.2 ± 1.7 mm2 vs. 10.8 ± 2.2 mm2, respectively, mean ± SD; p > 0.05). However, the amount of newly formed bone near the middle of the sinus membranes was significantly greater in group SFE than in group SFE_Perf (p < 0.05). There was no significant difference in the augmented volume. Fewer subepithelial glands and denser collagen fibres within the sinus membranes were observed in group SFE_Perf than in group SFE.

CONCLUSIONS

A large perforation of the sinus membrane followed by an 8-week healing period did not jeopardize new bone formation following SFE.

Schneiderian membrane perforation repair using a crosslinked collagen membrane: a retrospective cohort study

OBJECTIVES

Perforation of the Schneiderian membrane (SM) is a common intraoperative complication of sinus augmentation. This study aimed to evaluate risk factors for SM perforation, and to compare clinical outcomes between patients with SM perforation repaired using crosslinked collagen membranes (CLM) compared to those with an intact SM.

METHODS

A retrospective cohort study was conducted at a single tertiary medical center. Data was collected on patients requiring sinus augmentation via lateral approach prior to implant placement. The collected data included demographics, surgical details, implant outcomes, radiographic analysis, and presence of SM perforation. In cases of perforation a CLM was used to repair the SM. Statistical analysis was performed to evaluate risk factors for perforation and whether SM perforation repair using CLM influenced early implant failure (EIF). A p-value < 0.05 was considered significant.

RESULTS

Data on 194 individuals who underwent 278 lateral approach sinus augmentation procedures was collected. SM perforation occurred in 66 (23.74%) sinuses. Treatment of SM perforation using CLM yielded similar results to sinuses without perforations: EIF and the augmented gained bone did not correlate with SM perforation. Younger patients, and thick SMs (> 3 mm) had significantly lower risk of perforation.

CONCLUSIONS

Older age and thinner SMs are risk factors for sinus membrane perforations. No significant differences in bone gain and EIF were found between perforated and intact membranes.

CLINICAL RELEVANCE

Schneiderian membrane perforation repair using crosslinked collagen membrane provides comparable results to sinus augmentations without perforations, demonstrating its effectiveness in preventing complications.

Radiodiagnostic properties of maxillary antroliths: a retrospective cone beam computed tomography study

BACKGROUND

To evaluate the frequency and radiodiagnostic characteristics of maxillary antroliths using cone beam computed tomography.

METHODS

A review of 1166 patients aged 11-85 years was conducted to assess the frequency of maxillary antroliths, considering sex, age, and location. The relationship between antroliths and sex, location, dental treatment status, and sinus inflammation was evaluated. The shape, size, and volume of the antroliths were also analyzed. Data were analyzed using descriptive statistics, Mann-Whitney U, Kruskal-Wallis, Spearman rank correlation, independent t-tests, and Pearson Chi-square tests.

RESULTS

Forty-eight antroliths were detected in 41 patients (3.5%), with 16 in males and 25 in females. The frequency of antroliths was higher in the 81-90- and 31-40-years age groups (p < 0.001). The most common locations were the sinus floor (56.3%) and molar region (87.5%), with an amorphous shape (47.9%). Regarding the sinus-mucosa relationship, 66.7% of patients had mucosal thickness completely covering the antroliths, and 72.9% had less than one-third of the sinus opacified. Tooth extraction was the most common dental status near the antrolith (45.8%). The shape, size, and volume of antroliths did not affect the surrounding mucosal thickness (p > 0.05), but sinuses containing antroliths had significantly thicker mucosa than those without (p = 0.036).

CONCLUSIONS

The findings indicate that although antroliths are relatively rare, predominantly located on the sinus floor and in the molar region, their presence is associated with increased mucosal thickening regardless of their shape, size, or volume. Understanding their radiographic features can aid in differential diagnosis and help anticipate potential complications during surgical interventions.

TRIAL REGISTRATION

The trial protocol was retrospectively registered ID NCT06765148 ( https://clinicaltrials.gov/ ); 09/01/2025.

Prevention and management of intra-operative complications in maxillary sinus augmentation: A review

Maxillary sinus floor elevation is usually performed in two different ways: the lateral approach involves the creation of a bony window on the maxillary sinus lateral wall, providing direct access to the sinus cavity for membrane elevation and subsequent graft placement, and the transcrestal approach is considered less invasive. The aim of this article is to describe, based on the literature, how to anticipate, avoid, and manage the intraoperative complications that can occur with both approaches. For both approaches, the most common complication is the sinus membrane perforation. For the lateral approach, an average frequency ranging from 15.7% to 23.1% is reported, but because of the better visibility, their management will be easier compared to the transcrestal approach. Mean perforation rate reported for the transcrestal approach is lower (3.1%-6.4%), but it should be noted that a significant number of perforations cannot be detected and managed given the blind nature of this technique. Anatomical parameters such as sinus width and buccal wall thickness may be a risk factor for one approach and not the other. As it is impossible to assess the resistance of the Schneiderian membrane, the transcrestal approach is more likely to lead to infectious complications in the event of perforation. Others, such as the risk of vascular damage, are encountered only with the lateral approach, which can be prevented easily by dissecting the alveolo-antral artery. For both approaches, prevention is essential and consists in analyzing the anatomy, mastering the surgical technique, and collaborating with the ENT to manage the essentially infectious consequences of intraoperative complications.

Long-Term Clinical Outcomes of Transalveolar Maxillary Sinus Floor Elevation with Rotatory Instruments: An 8-Year Follow-Up Prospective Clinical Study

Background: Transalveolar sinus floor elevation (TSFE) is a surgical technique for the placement of dental implants in patients with reduced height of the maxillary posterior alveolar bone. This study aims to demonstrate the clinical outcomes of TSFE using the minimal invasive sinus elevation (MISE) technique in partially and totally edentulous maxillary patients. Methods: This prospective clinical study followed STROBE guidelines. TSFE was performed using the MISE technique with the simultaneous placement of implants. Dental implants were loaded at 6 months. Maxillary vertical bone gain was measured by CBCT, and marginal bone loss was assessed by periapical radiographs. Results: Ninety-one patients, with a mean age of 62.1 ± 11.8 years, were treated with TSFE and the placement of 107 implants, with a mean follow-up of 96.2 ± 11.7 months. An increase of 4.3 ± 0.4 mm in bone height was achieved, with a dental implant cumulative survival rate of 97.2%. Peri-implantitis was observed in 9.3% of implants, and membrane perforation occurred in 7.7% of cases. Technical complications were noted in 5.5% of patients. Conclusions: Within the limitations of this clinical study, it can be concluded that the MISE technique is a successful protocol for the placement of implants in the posterior maxilla with reduced height of the alveolar ridge, with a rate of biological and prosthetic complications below 10% over an average follow-up period of 8 years.

Cone beam computed tomography findings as prognostic factors for maxillary sinus membrane perforation during maxillary sinus augmentation

BACKGROUND

Maxillary Schneiderian membrane (SM) perforation is one of the complications of maxillary sinus (MS) augmentation. The aim of the present study was to analyse cone beam computed tomography (CBCT) findings to identify prognostic factors for SM perforation.

MATERIALS AND METHODS

50 CBCT scans were recruit for the analysis, 39 were suitable for analysis and met the inclusion criteria. Retrospective analysis of clinical and radiological CBCT findings of patients who underwent MS augmentation by lateral approach, divided into study group with SM perforation and control group without. Several radiological parameters were included MS lateral wall width, MS floor width, SM width, shape of the SM, level of MS ventilation, presence of septae, presence of blood vessels in the MS wall, the geometrical shape of the MS and sinus floor, presence of polyps and oroantral communication.

RESULTS

A thin MS floor, the presence of a Retention Pseudocyst, the presence of MS septae, a concave sinus floor and a triangular sinus shape are risk factors for perforation of the SM during open MS lift. Statistical significant difference between the groups were found regarding MS floor width.

CONCLUSION

Based on the results of this study, it can be concluded that careful analysis of CBCT reveals a number of significant radiological features that can be used to predict potential risks.

The Impact of Posterior Maxillary Teeth on Maxillary Sinus: Insights From Cone-Beam Computed Tomography Analysis

Background Odontogenic maxillary sinusitis arises mainly from dental origins, emphasizing the connection between dental health and sinus issues. Understanding these relationships is crucial for implant planning, sinus augmentation procedures, and managing post-extraction complications. This knowledge can help clinicians make informed decisions about treatment timing and approach. In this study, the influence of tooth periapical and periodontal conditions on maxillary sinus mucous membrane thickening using cone-beam computed tomography (CBCT) imaging was evaluated. Methods In this retrospective cross-sectional study, 124 patients who underwent CBCT for dental treatment covering 248 maxillary sinuses and 992 teeth were examined. Coronal and sagittal sections were examined to assess the maxillary sinus mucosal thickening (MT), the periodontal bone loss for maxillary posterior teeth, and their proximity to the maxillary sinus (RPMS). The mean ± standard deviation of quantitative variables was compared using a one-way ANOVA test. Multivariable logistic regression analysis was used to assess the relation between the different independent variables and MT of the maxillary sinus. P < 0.05 was considered to be statistically significant. Results MT was detected in 90 (72.6%) patients. We found 42 (33.9%) patients bilaterally. Grade 1 mucosal thickness was the most prevalent grade (72.5%), followed by Grade 2 (19.2%). Almost half the teeth examined were not in contact with the cortical borders of the sinus (56.0%). Most of the teeth showed mild to moderate periodontal bone loss (80.2%). Logistic regression analysis showed that the variables significantly associated with higher odds of MT of maxillary sinus occurrence were tooth location (second molar vs. first premolar AOR = 2.30, 95% CI: 1.29-2.79, first molar vs. first premolar AOR = 3.79, 95% CI: 1.82- 3.10, and second premolar vs. first premolar AOR = 1.57, 95% CI: 1.27-2.84), the relation of roots of posterior maxillary teeth to the sinus floor (Type 2 vs. Type 0 AOR = 2.27, 95% CI: 1.38-3.34, and Type 1 vs. Type 0 AOR = 2.24, 95% CI: 1.54-3.26), periodontal bone loss (severe vs. non-periodontitis AOR = 2.75, 95%CI: 1.29-5.86, and mild-moderate periodontitis vs. non-periodontitis AOR = 1.68, 95%CI: 1.19-4.93), and periapical and periodontal tooth condition (periapical lesion vs. extracted AOR = 32.7, 95% CI: 4.53-83.61, and no periapical lesion vs. extracted AOR = 19.8, 95% CI: 8.18-74.23). Conclusions Second molars, severe periodontal bone loss, and periapical lesions were associated with increased sinus MT risk, highlighting the need for dental health consideration in maxillary sinus management.

Anatomical Factors Affecting the Complexity of Maxillary Sinus Augmentation in Saudi Patients: A Cone Beam Computed Tomography (CBCT) Study

AIM

This study aims to evaluate the anatomical variations of the maxillary sinus and determine the difficulty score of maxillary sinus augmentation (MSA) in Saudi patients seeking dental implant rehabilitation of the posterior maxilla using cone beam computed tomography (CBCT).

METHODOLOGY

CBCT records of dental patients seeking treatment at a University Dental Teaching Hospital between 2019 and 2023 were retrospectively analyzed. Measurements were obtained from CBCT images, including membrane thickness, sinus width, buccal bone thickness, presence of maxillary sinus septa, residual alveolar ridge height, angle of the buccolingual sinus wall, and the presence of the alveolar antral artery (AAA). The difficulty score for MSA was determined based on these anatomical factors.

RESULTS

A total of 107 maxillary sinuses in 86 subjects were evaluated. The average membrane thickness was 2.23 mm, with males showing significantly higher thickness than females. Sinus septa were found in 54 (50.5%) sinuses, with 18 (17%) of sinuses having interfering septa. Twenty-three (21.5%) sinuses had a residual alveolar ridge height of less than 4 mm. The average angle of the buccolingual sinus wall was 79.39°, indicating a high prevalence of wide-shaped sinuses. The average sinus width was 14.09 mm, with 55 sinuses (51.4%) less than 15 mm. The average buccal bone thickness was 1.07 mm, in 29 (27%) sinuses, the thickness was more than 2 mm. AAA was visualized in 60 (56%) of sinuses, with 45 (42%) of sinuses having AAA interfering with the MSA window.

CONCLUSIONS

In this study, most sinuses were classified as simple or moderate difficulty, with higher membrane thickness, presence of septa, and AAA being the significant risk factors for complications. These findings provide valuable insights for implant surgeons in Saudi patients seeking dental implant rehabilitation of the posterior maxilla, enabling them to anticipate and minimize potential complications during MSA procedures.

Peri-implantitis and maxillary sinus membrane thickening: A retrospective cohort study

OBJECTIVE

The objective of this study is to investigate the association of peri-implantitis (PI) and sinus membrane thickening and to assess the resolution of membrane thickening following intervention (implant removal or peri-implantitis treatment) aimed at arresting PI.

MATERIALS AND METHODS

Forty-five patients with 61 implants in the posterior maxillary region were retrospectively included in the study. Twenty-four patients were diagnosed with peri-implantitis (PI) and 21 had peri-implant health (PH). Cone-beam computed tomography (CBCT) scans were evaluated to assess maxillary sinus characteristics, including membrane thickening, sinus occupancy and ostium patency. The CBCT scans taken 6 months after intervention aimed at arresting disease (implant removal or treatment of PI) in the PI group were also appraised and compared to baseline scans.

RESULTS

At baseline, all parameters evaluating membrane thickness disorders yielded significant differences between groups (p < .001). Patients with posterior maxillary implants diagnosed with PI were 7× more likely to present membrane thickening compatible with pathology when compared to patients with healthy implants (OR = 7.14; p = .005). Furthermore, the likelihood was 6x greater in implants diagnosed with PI to exhibit moderate membrane thickening (OR = 6.75, p = .001). The patients receiving interventions aimed at arresting PI experienced significant enhancement in all radiographic parameters related to the sinus cavity at the 6-month follow-up (p < .001), though these variations were similarly independent of whether treatment consisted of PI treatment or implant removal.

CONCLUSIONS

Maxillary sinus membrane thickening and the permeability/obstruction of the ostium are frequently associated with the presence of PI in posterior implants. Interventions targeting disease resolution effectively reduce membrane thickness to levels compatible with maxillary sinus health.

Influence of Schneiderian Membrane Perforation on Implant Survival Rate: Systematic Review and Meta-Analysis

Background: Maxillary sinus lift is a well-documented and accepted technique in the rehabilitation of the posterior maxilla. Schneiderian membrane perforation is the most common complication and may occur in between 7% and 56% of cases. Different materials and techniques have been described to achieve reparation of the perforation. The aim of this study was to establish whether the perforation of the Schneiderian membrane and its repair during maxillary sinus lift surgery results in a lower implant survival rate compared to those cases where the membrane has not been perforated. Materials and methods: A systematic review and meta-analysis of studies assessing the survival rate of implants placed in regenerated sinus using the lateral window approach, where the perforation of the Schneiderian membrane occur, was carried out. Statistical analysis was performed with Open Meta-Analyst, calculating the odds ratio of implants placed in perforated sinuses and non-perforated sinuses. Results: Ten articles were included in the qualitative analysis and seven articles in the quantitative analysis or meta-analysis. A total of 1224 maxillary sinus augmentation surgeries were performed without perforation of the Schneiderian membrane and 2725 implants were placed; 62 implants failed during the follow-up period with an overall survival rate of 97.7%. In 480 perforated sinuses, 1044 implants were placed, of which 30 failed; the overall survival rate was 97.1%. There were no significant differences between the implant survival rate of the implants in the two groups (OR = 0.78; CI = 0.49-2.23; p = 0.28 and I2 heterogeneity: 0%, p = 0.44). Conclusions: Schneiderian membrane perforation, as long as it is repaired, does not appear to negatively influence implant survival rate. Membrane perforation should not be considered a reason to abort the procedure or an absolute contraindication to implant placement.

Maxillary Postsurgical Ciliated Cysts (PSCCs): A Series of Three Cases

INTRODUCTION

A postsurgical ciliated cyst (PSCC) is an epithelial cyst that usually develops in the maxilla, although in rare cases, it can affect the mandible or other facial bones. The typical age of diagnosis is 40-50 years, with no gender prevalence, and the mean cyst development occurs approximately 10-15 years following a surgical or traumatic event. Some epithelial respiratory cells can be trapped into the bone tissue during maxillary surgical procedures or maxillary fractures. The pathogenetic mechanism can be attributed to an inflammatory process that stimulates epithelial proliferation, leading to cyst expansion caused by osmotic pressure difference.

METHODS

This study presents case series involving three surgical ciliated cysts located in the left maxilla, affecting two female patients (aged 49 and 55 years) and one male patient (aged 39 years). In all three cases, symptoms such as pain or swelling were mild and not consistently present. Two cases showed cyst development 10 and 15 years after implant placement, while one case was not associated with any surgical or traumatic event. CT scan identified well-defined unilocular lesions in the maxillary bone in each patient.

RESULTS

Histopathological examination of the surgical specimens confirmed the suspected diagnosis of a PSCC of maxilla. The cystic walls consisted of fibrous connective tissue with chronic inflammatory infiltrate, lined exclusively by a thin layer of ciliated pseudostratified columnar epithelium. In the third patient, it was not possible to rule out an unusual radicular cyst.

CONCLUSIONS

Although PSCCs are not commonly encountered in daily practice, clinicians should consider this possibility including it in the differential diagnosis of odontogenic jaw cysts and benign jaw tumors, particularly in patients who have undergone previous surgeries in the maxillary area.

Radiographic assessment of maxillary sinus membrane and lateral wall thickness using cone-beam CT in different facial types in southwestern Saudi Arabia

The anatomy of the edentulous posterior maxilla and maxillary sinus possess unique challenges in implant dentistry. The purpose of this study was to assess maxillary sinus membrane thickness (MT) and lateral wall thickness (LWT) in different facial index profiles and to describe the clinical implications. A retrospective image analysis of 75 CBCT scans was done, which yielded a total of 150 sinus images. The facial index was calculated as per the formula given in the text and grouped as euryprosopic, mesoprosopic and leptoprosopic. The images obtained were of 36 women (48%) and 39 men (52%), with maximum subjects in 30-39 years age group. MT and LWT were measured at three different points on the radiograph at every 3mm from the base of the sinus floor in premolar and molar regions of each image. Results showed females had significant differences from males in LWT in both premolar and molar regions (p = 0.018 and 0.032 respectively). Subjects in 40-49 years of age had significant differences (p = 0.021) in MT in premolar region only. Also, difference in MT in premolar and molar regions were also statistically significant. Lastly, the present study did not find any statistically significant difference in MT and LWT in all three facial indices groups. It can be concluded that different facial indices have no positive correlation with maxillary sinus membrane thickness and lateral wall thickness. Hence, surgical complications are avoidable with proper detailed knowledge and appropriate identification of the anatomic structures characteristic to the maxillary sinus.

Biomechanical analysis of the maxillary sinus floor membrane during internal sinus floor elevation with implants at different angles of the maxillary sinus angles

OBJECTIVE

This study analyzed and compared the biomechanical properties of maxillary sinus floor mucosa with implants at three different maxillary sinus angles during a modified internal sinus floor elevation procedure.

METHODS

3D reconstruction of the implant, maxillary sinus bone, and membrane were performed. The maxillary sinus model was set at three different angles. Two internal maxillary sinus elevation models were established, and finite element analysis was used to simulate the modified maxillary sinus elevation process. The implant was elevated to 10 mm at three maxillary sinus angles when the maxillary sinus floor membrane was separated by 0 and 4 mm. The stress of the maxillary sinus floor membrane was analyzed and compared.

RESULTS

When the maxillary sinus floor membrane was separated by 0 mm and elevated to 10 mm, the peak stress values of the implant on the maxillary sinus floor membrane at three different angles were as follows: maxillary sinus I: 5.14-78.32 MPa; maxillary sinus II: 2.81-73.89 MPa; and maxillary sinus III: 2.82-51.87 MPa. When the maxillary sinus floor membrane was separated by 4 mm and elevated to 10 mm, the corresponding values were as follows: maxillary sinus I: 0.50-7.25 MPa; maxillary sinus II: 0.81-16.55 MPa; and maxillary sinus III: 0.49-22.74 MPa.

CONCLUSION

The risk of sinus floor membrane rupture is greatly reduced after adequate dissection of the maxillary sinus floor membrane when performing modified internal sinus elevation in a narrow maxillary sinus. In a wide maxillary sinus, the risk of rupture or perforation of the wider maxillary sinus floor is reduced, regardless of whether traditional or modified internal sinus elevation is performed at the same height.

Maxillary sinus floor augmentation: a review of current evidence on anatomical factors and a decision tree

Maxillary sinus floor augmentation using lateral window and crestal technique is considered as predictable methods to increase the residual bone height; however, this surgery is commonly complicated by Schneiderian membrane perforation, which is closely related to anatomical factors. This article aimed to assess anatomical factors on successful augmentation procedures. After review of the current evidence on sinus augmentation techniques, anatomical factors related to the stretching potential of Schneiderian membrane were assessed and a decision tree for the rational choice of surgical approaches was proposed. Schneiderian membrane perforation might occur when local tension exceeds its stretching potential, which is closely related to anatomical variations of the maxillary sinus. Choice of a surgical approach and clinical outcomes are influenced by the stretching potential of Schneiderian membrane. In addition to the residual bone height, clinicians should also consider the stretching potential affected by the membrane health condition, the contours of the maxillary sinus, and the presence of antral septa when evaluating the choice of surgical approaches and clinical outcomes.

Correlation between periodontal phenotype and sinus membrane thickness: A systematic review

AIM

To assess the correlation between the periodontal phenotype (PP) and sinus membrane thickness (SMT) in humans.

METHODS

This review was conducted according to the PRISMA guidelines. Two reviewers independently carried out electronic and manual literature searches of studies published in English, German, and Spanish, from 1970 to September 2022 in four electronic databases, PubMed/Medline, Scopus, Cochrane Library, and Web of Science, in addition to gray literature. Studies that assessed the correlation between PP and SMT in adults (aged 18 years) were included. Methodological quality was evaluated using the Appraisal Tool for Cross-Sectional Studies (AXIS) for articles that met the eligibility criteria.

RESULTS

Six studies, including 510 patients, were considered for qualitative analysis. All included studies were cross-sectional, and the correlation between the PP and SMT was evaluated, finding a positive and high correlation in 83.3% of them, based on a value of ≥0.7. All the included studies were assessed with a high overall risk of bias.

CONCLUSIONS

Periodontal phenotype and sinus membrane thickness are likely correlated. Nevertheless, further standardized studies are required to draw definitive conclusions.

Risk factors and longitudinal regenerative outcomes of sinus membrane perforation during lateral window sinus floor elevation: A retrospective analysis up to 9 years

BACKGROUND

Lateral-window sinus floor elevation (LSFE) is a reliable procedure to reconstruct the posterior maxilla for implant therapy. This retrospective study aimed to investigate risk factors associated with Schneiderian membrane perforation (SMP) occurrence during LSFE and longitudinal regenerative outcomes following LSFE up to 9 years.

METHODS

Patients who had LSFE between 2010 and 2019 were included. All demographic and surgical-related data were retrieved from existing electronic health records. Radiographs were used to evaluate the vertical dimensional changes of ridge and graft materials and the potential anatomic factors of SMP.

RESULTS

A total of 122 LSFE procedures in 99 patients were included in the study. Mean ridge height gain and graft shrinkages were 9.5 ± 3.47 and 1.57 ± 2.85 mm. The influence of the healing period on graft shrinkage showed a positive trend; the longer the healing period, the greater the graft shrinkage (p = 0.09). The pathology in the sinus showed a positive correlation with SMP (p = 0.07). However, other anatomical factors did not negatively impact SMP and subsequent ridge height gain (p > 0.05).

CONCLUSIONS

With inherent limitation, the findings with up to 9 years of follow-up indicate a consistent ridge remodeling lasting for about 3 years after LSFE procedures. SMP or membrane thickening may not significantly affect the ridge gain following LSFE. The healing period had the most significant influence on graft shrinkage, showing that the longer the healing time between LSFE and implant placement, the greater the graft shrinkage.

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

BACKGROUND

Maxillary 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 METHODS

This 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.

RESULTS

The 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%).

CONCLUSION

Based 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.

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

Objectives

This 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).

Methods

In 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.

Results

A 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).

Conclusions

The 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.

Which factors affect the risk of membrane perforation in lateral window maxillary sinus elevation? A prospective cohort study

It was the aim of this prospective cohort study to assess the various anatomical and other patient-related factors that increase membrane perforation risk. Patients underwent cone-beam computed tomography (CBCT) before surgery. The presence of septa, presence of mucous retention cyst, lateral wall thickness, membrane thickness, and residual bone height were predictive factors. Age, gender, and smoking were covariates for the study. The presence or absence of membrane perforation was the study outcome. In total, 140 subjects were studied. The hazard ratio (HR) for the presence of septa with membrane perforation was 8.07 (2.93-22.29) (p < 0.001). The HR for perforation with a single edentulous area relating to two or more teeth was 68.09 (9.52-49.16). The risk of membrane perforation in smokers was 25 times more than in non-smokers - HR 25 (7.58-82.51) (p < 0.001). The HR for membrane perforation in subjects with mucous retention cysts compared with subjects without retention cysts was 27.75 (8.73-88.23) (p < 0.001). Within the limitations of the study it seems that anatomical, habitual, and pathological factors may increase the risk of Schneiderian membrane perforation when a lateral window approach is used for sinus floor augmentation.

Association between smoking and Schneiderian membrane perforation during maxillary sinus floor augmentation: A systematic review and meta-analysis

OBJECTIVE

To estimate the association between smoking and Schneiderian membrane perforation in sinus floor augmentation.

MATERIALS AND METHODS

Searches were conducted in PubMed, Web of Science, Embase, and Cochrane Library. Data were extracted by two authors independently. The inclusion criteria were the (1) age of patients >18, (2) the number of participants >10, and (3) smoking and the patients of Schneiderian membrane perforation were accurately recorded. The risk of bias was assessed by the Newcastle-Ottawa scale (NOS). Statistics analyses were conducted using Reman5.4.1 and Stata (15.0). The association of Schneiderian membrane perforation with smoking habits during maxillary sinus floor elevation was expressed as odds ratios (ORs) with a 95% confidence interval (95% CIs). And the I2 statistic was used to estimate statistical heterogeneity. The funnel plot and Egger's tests were used to evaluate the reliability and stability of the results.

RESULTS

Of 1463 articles screened, nine studies were included in our systematic review, and eight were synthesized for meta-analysis. Eight were retrospective observational studies and one was a clinical trial, with a total of 1424 patients included. The nine studies were proved as high quality according to the NOS. There was no significant publication bias in the studies (p = 0.827). A random-effects model was used because of differences in the adopted methodologies (p = 0.39, I2  = 5%). During maxillary sinus augmentation, smoking and Schneiderian membrane perforation were associated (odds ratios, 1.58 [95% CI, 1.10-2.25]).

CONCLUSION

Smoking increased the risk of membrane perforation in maxillary sinus floor augmentation. Our evaluation was limited by the poor reporting of the number of cigarettes smoked per day (PROSPERO number was CRD42022306570).

Sinus augmentation procedure via the lateral window technique-Reducing invasiveness and preventing complications: A narrative review

Sinus augmentation has become an integrated surgical phase in posterior maxillary implant prosthesis reconstruction. Since the residual alveolar bony height usually requires additional volume particularly at this anatomical region, sinus floor augmentation is advocated routinely. Over the years, Implant success rate is proved to be comparable to the one in the pristine bone, which is well documented in the literature. Anatomical aspects as well as surgeon skills are at most importance to achieve predictable outcome. In this narrative review, the different osteotomy techniques, the indications toward 1 or 2-stage approaches, the control of the Schneiderian membrane integrity as well as the management of intra- and post-operative complications are thoroughly discussed according the current data. In light of the excellent long-term implant success rate concurrent with the application of contemporary advanced techniques of the sinus augmentation via the lateral wall osteotomy approach, reduce invasiveness and less complication occurrences are well documented. A well-codified patient selection involving the rhinologist as an integral medical team would be significantly beneficial toward early diagnosis. In-depth knowledge of the anatomy, execution of a well standardized surgical technique, and understanding the complication etiology and their management are prerequisites for reducing patient morbidity to minimal discomfort and predictable successful outcome.

A novel lineage of osteoprogenitor cells with dual epithelial and mesenchymal properties govern maxillofacial bone homeostasis and regeneration after MSFL

Bone regeneration originates from proliferation and differentiation of osteoprogenitors via either endochondral or intramembranous ossification; and the regeneration capacities decline with age and estrogen loss. Maxillary sinus floor lifting (MSFL) is a commonly used surgical procedure for guiding bone regeneration in maxilla. Radiographic analysis of 1210 clinical cases of maxilla bone regeneration after MSFL revealed that the intrasinus osteogenic efficacy was independent of age and gender, however; and this might be related to the Schneiderian membrane that lines the sinus cavity. In view of the particularity of this biological process, our present study aimed to elucidate the underlying mechanism of MSFL-induced bone regeneration. We first established a murine model to simulate the clinical MSFL. By single-cell RNA-sequencing and flow cytometry-based bulk RNA-sequencing, we identified a novel Krt14⁺Ctsk⁺ subset of cells that display both epithelial and mesenchymal properties and the transcriptomic feature of osteoprogenitors. Dual recombinases-mediated lineage tracing and loss-of-function analyses showed that these Krt14⁺Ctsk⁺ progenitors contribute to both MSFL-induced osteogenesis and physiological bone homeostasis by differentiating into Krt14^-Ctsk⁺ descendants which show robust osteogenic capacity. In addition, we detected a similar population of Krt14⁺Ctsk⁺ cells in human samples of Schneiderian membrane, which show a highly similar osteogenic potential and transcriptomic feature to the corresponding cells in mice. The identification of this Krt14⁺Ctsk⁺ population, featured by osteoprogenitor characteristics and dual epithelial-mesenchymal properties, provides new insight into the understanding of bone regeneration and may open more possibilities for clinical applications.

Application of a Cone-Beam Computed Tomography-Based Index for Evaluating Surgical Sites Prior to Sinus Lift Procedures-A Pilot Study

OBJECTIVES

Radiography-based indices can help surgeons perform detailed examinations of the surgical site and predict the surgical difficulty of cases. We aimed to develop and validate a novel CBCT-based index that can predict the surgical difficulty of sinus-augmentation procedures.

MATERIALS AND METHODS

In the first stage, five experienced dental specialists performed a review of the literature and closed group discussions and designed the novel index. In the next stage, the index was validated. CBCT scans of 30 patients scheduled for sinus-augmentation procedures were evaluated and assigned presurgical CBCT evaluation scores (PSCESs) by five examiners. Subsequently, one oral surgeon performed sinus augmentation using the lateral antrostomy technique and assigned surgical difficulty scores (SDSs) to each of the 30 cases along with 2 observers. The PSCESs and SDSs were statistically analysed to determine the interrater reliability and validity of the index.

RESULTS

The interrater agreement of the PSCES among the five presurgical evaluators was 0.85. The PSCES of the five evaluators had highly significant correlation (P < 0.001, r = 0.68 to 0.76) with the SDS. Regression analysis revealed that for every unit increase in the PSCES, there is 0.46 to 0.57 increase in the SDS value.

CONCLUSION

The results of this pilot study revealed that a novel CBCT-based index can be used as a reliable tool for predicting the surgical difficulty of sinus-augmentation procedures. However, the novel index needs to be tested on a larger sample of patients and evaluators for a more concrete validity and reliability.

Risk factors for sinus membrane perforation during lateral window maxillary sinus floor elevation surgery: A retrospective study

PURPOSE

To analyze the sinus membrane perforation (SMP) rate and its potential risk factors during lateral window maxillary sinus floor elevation (LSFE).

MATERIALS AND METHODS

For patients with LSFEs at Department of Implantology, Stomatology Hospital, School of Medicine, Zhejiang Universitiy during January 2014 to December 2020, patient-related risk factors (age/sex/smoking habit), surgery-related risk factors (operator experiment/number of tooth units/technique of osteotomy/surgical approach), and maxillary sinus-related risk factors (residual bone height/sinus membrane thickness/lateral wall thickness/maxillary sinus contours/presence of septa/blood vessels at the lateral maxillary sinus wall) were compared between perforated and nonperforated sites and were evaluated for their influence affecting SMP.

RESULTS

The study sample comprised 278 LSFE procedures in 278 patients; a total of 47 LSFE procedures (16.91%) presented SMP. Four significant factors were identified: smoking habit (p < 0.001), thin (≤1.5 mm) sinus membrane (p = 0.027), maxillary sinus contours (p < 0.001), and presence of septa (p = 0.001). The SMP rate of irregular, narrow tapered, and tapering sinus contours was significantly higher than that of ovoid and square one (p < 0.05).

CONCLUSION

In general, smoking habit, thin sinus membrane, irregular, narrow tapered, and tapering sinus contours, and presence of septa may increase the risk of SMP during LSFE.

Prevalence, risk factors, and repair mechanism of different forms of sinus membrane perforations in lateral window sinus lift procedure: A retrospective cohort study

OBJECTIVES

To evaluate prevalences, affecting risk factors and efforts for repair mechanism for different forms of sinus membrane perforations (SMP) during sinus floor elevation (SFE) using the lateral window technique (LWT).

MATERIAL AND METHODS

For 334/434 patients, SFE undergoing LWT prevalence of SMP was retrospectively evaluated including a subselection based on membrane perforation size (<10 mm: small-moderate/≥10 mm: large) and biotype (BT; thick BT/thin BT) into four subgroups (SMP1: thick BT/small-moderate; SMP2: thin BT/small-moderate; SMP3: thick BT/large; SMP4: thin BT/large). For the various subgroups, patient- and surgery-related/anatomic risk factors affecting SMP were evaluated and the scope of sinus membrane repair (SSMR) mechanisms rated with 1 (easy) to 5 (complex) was compared.

RESULTS

For 103/434 SMP (27.6%) in 93/334 patients (30.8%) the prevalence of various forms of SMP differed significantly (p < 0.001) among the four subgroups. SMP4 with a prevalence of 45.6% (n = 47) was the most frequent type, while SMP3 had low prevalence with 4.85% (n = 5). Small/moderate SMPs with thick (SMP1: n = 26) or thin BT (SMP2: n = 23) were seen in 26.2% and 23.3%, respectively. Univariate analysis showed significant differences between subgroups with large perforations (SMP3/SMP4) and those with small/moderate perforations (SMP1/SMP2) regarding anatomic risk factors such as residual ridge height (p = 0.023) and history of previous oral surgical interventions (OSI; p = 0.026). Most evidently, multivariate analysis showed that induction of large SMP with thin biotype (SMP4) was significantly affected by the presence of sinus septa (p < 0.022, OR: 2.415), reduced residual ridge height (p < 0.001, OR: 1.842), and previous OSI (p < 0.001, OR: 4.545). SSMR differed significantly (p < 0.001) between SMP4 (4.62 ± 0.49) and the subgroups SMP1 (1.11 ± 0.32), SMP2 (1.08 ± 028), and SMP3 (2.2 ± 0.55).

CONCLUSION

The most frequently found type of SMP had characteristics of thin biotype and large size associated with risk factors such as sinus septa, reduced residual ridge, and previous surgical interventions and required challenging repair mechanisms assessing clinical impact.

Gingival Biotype and Its Relationship With the Maxillary Membrane and Lateral Wall Thickness

The purpose of this study was to analyze the risk of the maxillary sinus lift technique and the correlation between the thickness of the gingiva, maxillary sinus membrane, and the maxillary sinus lateral wall. Cone-beam computerized tomograhy (CBCT) records of 32 adult dentate patients (10 male/22 female) were analyzed. The gingival thickness records of the dental units were compared with the thickness measurements of the membrane and lateral wall of the maxillary sinus. The gingival biotypes varied between 1.1 mm (thin) and 1.6 mm (thick), with a small association with sex. The thickness of the sinus membrane presented a small association between sexes (0.2 mm, female/0.3 mm, male) and gingival biotypes (Cohen d = .52). The lateral wall presented a weak association between the biotypes (1.3 mm, thin/1.1 mm, thick). There was also no correlation between the membrane and lateral wall (r = -.22). The volume dimension related to the graft area of the sinus was 4 mm3 for men and 5 mm3 for women. There was a weak correlation of gingival thickness compared with membrane thickness and lateral wall of the sinus (r = .304/r = -.31). Gingival thickness does not appear to be a reliable thickness predictor of the membrane or lateral wall of the maxillary sinus. The analysis of maxillary sinus anatomical structures through CBCT is the most reliable technique to identify the thickness of the membrane and lateral wall of the maxillary sinus before surgery. We believe that new studies are necessary to confirm our findings.

A modified transalveolar sinus floor elevation approach with a bilaterally enlarged osteotomy

Sinus floor elevation is the most commonly used method for vertical bone augmentation in the maxillary posterior area. This clinical report describes a modified transalveolar approach to elevate the sinus floor when placing implants on a severely resorbed maxillary posterior ridge with a buccal-palatal distance of more than 8.0 mm. In this approach, the osteotomy prepared on the crestal is bilaterally enlarged to 8.0-10.0 mm. The enlarged osteotomies can provide better access for practitioners, so that instruments can touch directly to the sinus floor and the Schneiderian membrane can be elevated with a reduced risk of perforation.

Endoscope-controlled maxillary sinus floor elevation: a review of the literature

A systematic review of the literature was conducted to assess the safety and efficacy of endoscope-assisted maxillary sinus elevation. PubMed, Embase, Web of Science, and the Cochrane database were searched for articles in English. Published studies involving patients who had undergone endoscope-assisted maxillary sinus floor augmentation were selected. The validity of the included articles was evaluated. After going through full texts, a total of 12 studies met the eligibility criteria and were included. It was concluded that endoscope-controlled maxillary sinus floor elevation was a viable and beneficial method, providing direct visualisation of the integrity of the mucosa and placing of bone graft material. The endoscope could be inserted into the maxillary sinus lumen, subantral space below the Schneiderian membrane, or through the alveolar crest. With the endoscope, perforations can be detected and managed precisely. However, high-quality clinical trials are still needed to validate the predictability and advantages of this surgical procedure.

Factors influencing the sinus membrane thickness in edentulous regions: a cone-beam computed tomography study

BACKGROUND

During implant treatment in the maxillary molar area, maxillary sinus floor augmentation is often performed to ameliorate the reduced alveolar bone height attributable to bone remodeling and pneumatization-induced expansion of the maxillary sinus. However, this augmentation may cause complications such as misplaced implants, artery damage, and maxillary sinus mucosal perforation; infections like maxillary sinusitis; and postsurgical complications such as bone graft leakage and postoperative nasal hemorrhaging. To reduce the complications during maxillary sinus floor augmentation and postoperative infections, we performed retrospective investigations of various systemic and local factors that influence pre-operative sinus mucosal thickness (SMT) by using cone-beam computed tomography (CBCT). Subjects included patients who underwent maxillary sinus floor augmentation in an edentulous maxillary molar area with a lateral approach. Pre-operative SMT, existing bone mass, and nasal septum deviation were measured using CBCT images. Relationships between SMT and the following influencing factors were investigated: (1) age, (2) sex, (3) systemic disease, (4) smoking, (5) period after tooth extraction, (6) reason for tooth extraction, (7) residual alveolar bone height (RBH), (8) sinus septa, and (9) nasal septum deviation. Correlations were also investigated for age and RBH (p < 0.05).

RESULTS

We assessed 35 patients (40 sinuses; 11 male, 24 female). The average patient age was 58.90 ± 9.0 years (males, 57.9 ± 7.7 years; females, 59.9 ± 9.4 years; age range, 41-79 years). The average SMT was 1.09 ± 1.30 mm, incidence of SMT > 2 mm was 25.0%, incidence of SMT < 0.8 mm was 50.0%, and the average RBH was 2.14 ± 1.02 mm. The factors that influenced SMT included sex (p = 0.0078), period after tooth extraction (p = 0.0075), reason for tooth extraction (p = 0.020), sinus septa (p = 0.0076), and nasal septum deviation (p = 0.038).

CONCLUSIONS

Factors associated with higher SMT included male sex, interval following tooth extraction < 6 months, periapical lesions, sinus septa, and nasal septum deviation. Factors associated with SMT > 2 mm were sex and reason for tooth extraction, while factors associated with SMT < 0.8 mm were time following tooth extraction and nasal septum deviation. Despite the limitations of this study, these preoperative evaluations may be of utmost importance for safely conducting maxillary sinus floor augmentation.

The impact of anatomic, patient and surgical factors on membrane perforation during lateral wall sinus floor elevation

OBJECTIVES

This retrospective study aimed to evaluate the influence of anatomical, patient and surgical factors on the occurrence of membrane perforation (MP) during lateral window sinus floor elevation (LWSFE).

MATERIAL AND METHODS

A review of LWSFE patient records between 2014 and 2019 accounted for MP occurrence, window surface area (WSA), intravenous sedation use, osteotomy instrument type and clinician experience. Preoperative cone beam computed tomography (CBCT) scans were analyzed for lateral wall thickness (LWT), LFM and LAM angles formed between lateral and medial walls at the floor and anterior wall, respectively, sinus width at 5-, 10- and 15-mm (LM-5, LM-10 and LM-15) from the floor, residual bone height (RBH), sinus pathologies, septa and arterial anastomoses. The generalized estimating equation (GEE) approach with a sandwich variance-covariance estimator was used to evaluate the associations with MP.

RESULTS

MP occurred in 25.74% of 202 LWSFE procedures (166 patients). Mean 1.6 mm-LWT, 3.2 mm-RBH, 95°-LFM, 75.5°-LAM, 12 mm-LM-5, 20.79% septa, 16.83% arterial anastomosis, 37.62% sinus pathology and 29.21% intravenous sedations, 85.24% WSA ≥ 40 mm² and 57% >10 procedures/clinician were reported. Greater MP rates were encountered as follows: 38.3% (LWT ≥ 1.5 mm), 38% (LFM < 90°), 59.6% (LAM < 70°), 45.4% (LM-5 < 10 mm) and 36.4% (WSA ranged > 80 mm² ), with statistically significant associations with all these outcomes (p < .05). The presence of pathologies was also associated with MP (p = .013). Associations between MP and the presence of septa and arterial anastomoses, age/gender, right/left sinus, RBH, clinician's experience, instrument type and intravenous sedation use could not be demonstrated.

CONCLUSIONS

MP is significantly associated with thicker lateral walls, narrower sinuses, larger windows and existing sinus pathology.

Anatomical characteristics of maxillary sinus antroliths and their influence on sinus membrane thickness: a retrospective cone beam computed tomography analysis

The purpose of this study was to assess the anatomy of antroliths and its influence on the thickness of the maxillary sinus membrane. Cone beam computed tomography (CBCT) was performed on 239 patients (478 sinuses). The prevalence of antroliths per sinus was 8.4%. Regarding their distribution, antroliths were predominantly unilateral (82.5%), single (67.5%), and in a dentate area (60.0%). The antroliths were mainly located in the molar region (95.0%) and in the sinus floor (77.5%). The measured dimensions of the antroliths were as follows: length 5.6±4.4mm, width 4.1±2.9mm, height 3.5±2.1mm. The relationships between the antroliths and the sinus membrane (type 1, 34.1%; type 2, 52.3%; type 3, 13.6%) indicated that sinus membranes tended to encircle antroliths, which resulted in a gradual increase in membrane thickness. The sinus membrane was found to be significantly thicker in the presence of antrolith(s) (P<0.001). Antroliths which are sufficiently large or are located adjacent to the sinus floor or lateral wall increase the risk of sinus membrane perforation during sinus augmentation procedures. Therefore, a thorough CBCT evaluation is needed to minimize the risk of complications prior to sinus augmentation procedures.

HOSPITAL INTERVENTION IN SEVERE SINUS INFECTION AFTER BONE GRAFT

This study presents the case of a patient who required antrostomy under general anesthesia to treat a sinus lift complication. The patient was a 43-year-old woman with no systemic abnormalities, who underwent maxillary sinus lift surgery associated with mineralized bovine bone graft. The Schneiderian membrane was perforated during the procedure and the rupture was treated with collagen membranes to close the wound and contain the biomaterial, preventing its dispersion. The patient developed a maxillary sinus infection seven days after the surgery. This infection was initially treated with 875 mg of amoxicillin combined with 125 mg of clavulanic acid. Although the initial infection did not worsen, the patient developed maxillary sinusitis. Thirty days after the onset of the initial infection, the patient underwent an intraoral surgery under local anesthesia to remove the biomaterial and clean the sinus cavity. Despite this procedure, maxillary ostial patency was still compromised and antrostomy was performed endoscopically in a hospital setting under general anesthesia. This procedure resolved the sinus infection. Then, 12 months after hospitalization, the patient was treated with another sinus graft surgery without postoperative complications. The treatment of sinus infections due to graft surgery may require early and active intervention with antibiotics, graft removal, and antrostomy to prevent major complications.

Does sinus floor elevation in the presence of Schneiderian membrane pathology increase therisk of membrane perforation and implant failure rate?

Schneiderian membrane (SM) thickness >2mm is regarded to be a pathological mucosal change. The aim of the current study is to answer the question" Does presence of pathological changes in the SM increase the risk of sinus perforation during surgical sinus floor elevation (SFE)?" An electronic database (PubMed, Embase, Cochrane Library, and Chinese database) were systemically searched for the studies published until February 2020. Randomized and non-randomized studies that reported the incidence of SM perforation in patients with SM pathology (antral pseudocyst or mucosal thickening) during SFE. The outcome measures were the incidence of SM perforation and implant survival rate. The pooled odds ratio (OR) with 95% confidence intervals and the Fixed-effects model were calculated. P-value ≤ 0.05 was considered to be statistically significant. Eighteen studies with a total of 1542 patients and 1797 SFE were included. Statistically insignificant difference in the incidence of SM perforation was observed between the normal-appearing sinus and thickened sinus mucosa (Fixed; OR, 0.896; 95%CI, 0.504 - 1.59; P =0.707, I 2 =32%). The rate of SM perforation in the normal sinus, mucosal thickening, and antral pseudocysts was 14%, 6%, and 6% respectively. The Implant survival rate was 98% in the normal sinus, and 100% in antral pseudocyst and mucosal thickening. SM thickening or antral pseudocyst did not increase the risk of membrane perforation and implant failure rates. Future RCTs are needed to evaluate the risk of the presence of pathological changes in the SM on the failure of the bone augmentation and dental implant.

Collagenated Synthetic Bone Substitute Material for Sinus Floor Elevation at Sites with a Perforated Schneiderian Membrane

Schneiderian membrane perforation (SMP) is the most common complication during sinus floor elevation (SFE). Conventional methods to repair SMP, such as using a collagen barrier, may be clinically demanding. The aim of the present study was to compare the effects of collagenated bone substitute materials with and without a collagen barrier to repair SMP during SFE in terms of new bone formation and dimensional stability. In 12 rabbits, intentional SMP was made during bilateral SFE. The rabbits were randomly assigned under two groups: the control group, in which the sinus was repaired with a collagen barrier, and the test group, in which the sinus was repaired without a collagen barrier. Collagenated bone substitute material was grafted in both groups. Healing periods of 2 weeks and 4 weeks were provided in both groups. There were no adverse clinical events. Histology revealed that the Schneiderian membrane had atrophied with loss of cilia and serous glands in both groups at 4 weeks. Histomorphometry revealed that the newly formed bone (test: 0.42 ± 0.17 mm², control: 0.36 ± 0.18 mm² at 2 weeks; test: 1.21 ± 0.36 mm², control: 1.23 ± 0.55 mm² at 4 weeks) or total augmented area did not significantly differ between the two groups at either time points (p > 0.05). In conclusion, collagenated bone substitute material without a collagen barrier demonstrated similar new bone formation and dimensional stability as that with a collagen barrier in repairing SMP.

Clinical and radiographic outcomes of reentry lateral sinus floor elevation after a complete membrane perforation

BACKGROUND

Although small perforation of the maxillary sinus schneiderian membrane is a well-documented complication during lateral sinus floor elevation (LSFE), complete perforations larger than 10 mm often result in discontinuation of surgery. Reports on reentry LSFE and its long-term outcomes are sparse.

PURPOSE

To evaluate the long-term outcomes of reentry LSFE following complete membrane perforation to elucidate the technical details of the reentry procedure.

MATERIALS AND METHODS

We assessed the medical records of all patients receiving LSFE from 2008 to 2017 in the Department of Oral Implantology, Peking University Hospital of Stomatology. Twenty-two patients receiving reentry LSFE after complete membrane perforation were enrolled. Data were recorded using cone beam computer tomography: including the residual bone height, membrane thickness of the sinus prior to surgery (MT₁ ), and before reentry (MT₂ ), and height of the bone graft during the reentry procedure (HBG). Cumulative survival rate of implants (CSR), marginal bone loss (MBL), and subsequent complications were also recorded.

RESULTS

From 2008 to 2017, 2023 consecutive patients (2262 sinuses) who underwent LSFE were screened. Complete membrane perforation occurred in 28 patients and resulted in discontinuation of surgery (1.2%). Twenty two patients were enrolled and received reentry LSFE within 3-6 months. Two patients undergoing the reentry procedure were suspended due to excessive membrane perforation, while the other 20 finished reentry sinus bone graft. In the reentry procedure, the HBG was 9.73 ± 2.67 mm with 34 implant placements. The MT₁ and MT₂ were 1.03 ± 0.43 and 1.91 ± 1.45 mm, respectively, showing a statistically significant difference (P < .05). After a follow-up of 2-10 years, CSR was 97.1%, and MBL was 0.64 ± 0.50 mm.

CONCLUSIONS

The long-term outcome of reentry LSFE is predictable and reentry LSFE offers a reliable alternative following complete membrane perforation. However, the procedure is relatively sensitive and should be performed by experienced surgeons.

The effect of residual bone height and membrane thickness on sinus membrane perforation in crestal sinus grafting: A prospective clinical study

This study sought to determine the rate of sinus membrane perforation in patients undergoing crestal sinus grafting, as well as the effect of Schneiderian membrane thickness and residual bone height (RBH) on membrane perforation, using cone beam computed tomography. The study included 25 patients undergoing 44 crestal sinus grafting procedures. The sites for crestal sinus grafting were divided into a control group (RBH≥5mm) and a test group (RBH<5mm). All sinus grafting procedures were also categorised based on membrane thickness: group A (<1mm), group B (1-2mm), and group C (≥2mm). The rate of membrane perforation was 18.2%. The median RBH measurement was 5.59mm. No statistically significant difference in membrane perforation rate was found between the test and control groups (P=0.262). The median thickness of the Schneiderian membrane was 1.35mm. There was no statistically significant difference in membrane perforation among the three membrane thickness groups (P=0.431). No significant correlation between RBH and membrane perforation was observed, although clinical observation indicated that there was a tendency for an increased membrane perforation rate in the presence of a RBH<5mm. The perforation rate was found to be at its highest when the membrane was thinner than 1mm.

CBCT Study of Morphologic Variations of Maxillary Sinus Septa in Relevance to Sinus Augmentation Procedures

Background:

Augmentation of the maxillary sinus increases the lost height of ridge in the posterior maxilla. Bony convolutions from the floor of the sinus called septa may be encountered during the procedure and significantly impact the outcome of the procedure.

Materials and Methods:

For this retrospective study, 120 cone-beam computed tomography (CBCT) scans were collected from the archives of the department of oral radiology in the time period between January 2016 and August 2018. Planmeca Romexis^® software version 3.2.7 was used to check for the incidence, and then among the septa, plane of orientation, location with respect to the wall of the sinus, and in terms of relation to tooth were examined. The average height and average width of all the septa were measured using a measuring tool in the software.

Results:

Thirty-five of the total 88 patients showed septa in 40 sinuses, in which 36 sinuses showed one septum and 4 sinuses showed 2 septa. Forty-one septa were located on the floor of the sinus in the frontal orientation and 3 septa were located on the lateral wall of the sinus in the axial orientation. The mean height and mean width of the 41 septa on the floor of the sinus were 5.72 mm and 3.47 mm, respectively. The mean height of septa found on the lateral wall of the sinus was 5.59 mm.

Conclusion:

Septa had a higher tendency to be in bucco-palatal direction and on the floor of the sinus and frequent occurrence in the region of molars. A thorough prediagnostic evaluation using CBCT is necessary prior to sinus augmentation procedures.

French Otorhinolaryngology Society (SFORL) good practice guidelines for dental implant surgery close to the maxillary sinus

OBJECTIVES

To draw up guidelines for ENT management associated with dental implant surgery with or without sinus lift.

MATERIALS AND METHODS

The methodology followed the rules of laid down by the French Health Authority (HAS): "Methodological bases for drawing up professional recommendations by formalized consensus". The chosen method was the RAND/UCLA "RAND appropriateness method" (short version).

RESULTS

In the pre-implantation check-up, it is recommended to systematically screen for sinonasal pathology on medical interview and to favor 3D CT or cone-beam imaging. It is recommended that imaging include the entire maxillary sinus when the patient does not have sinonasal history or functional signs on interview. Otherwise, examination of all sinonasal cavities is recommended. This attitude enables simultaneous analysis of maxillary infrastructure for pre-implantation work-up and assessment of sinonasal cavity status. Sinus mucosal incidentalomas are very common in the healthy population and must be assessed with reference to the clinical, endoscopic and radiological context.

CONCLUSION

This formalized expert consensus establishes a common base of knowledge, to clarify the issues and clinical situations and to standardize practices.

The maxillary sinus: physiology, development and imaging anatomy

OBJECTIVES

The maxillary sinus is of paramount importance for otolaryngologists, rhinologists, oral and maxillofacial surgeons, head and neck and dental and maxillofacial radiologists. A comprehensive review article concerning the physiology, development and imaging anatomy was undertaken.

METHODS

Relevant literature pertaining to the physiology of the sinonasal cavity, development of the paranasal sinuses and imaging anatomy of the maxilla and maxillary sinus from 2000 to 2019 was reviewed. Emphasis was placed on literature from the last 5 years.

RESULTS

Extensive recent research using imaging has provided new insights into the development of the maxillary sinus, the other paranasal sinuses and the midface. The fundamental physiological concept of mucociliary clearance and its role in sinus health is emphasized. The paranasal sinuses are an integral part of a common mucosal organ formed by the upper and lower airway.An in-depth understanding of the soft-tissue and neurovascular relationships of the maxillary sinus to the deep fascial spaces and branches of the trigeminal nerve and external carotid artery respectively is required to evaluate and report imaging involving the maxillary sinus.Sinusitis of rhinogenic, rather than odontogenic origin, originates from nasal inflammation followed by anterior ethmoid disease and secondary obstruction of the ostiomeatal unit. The role of anatomical variants that predispose to this pattern of disease is discussed in detail with illustrative examples.The maxillary sinus is intimately related to the roots of the posterior maxillary teeth; the high frequency of mucosal disease and sinusitis of odontogenic aetiology is now well recognized. In addition, an understanding of the anatomy of the alveolar process, morphology of the alveolar recess of the maxillary sinus and neurovascular supply are essential both for deliberate surgical intervention of the sinus and complications related to oral surgical procedures.

CONCLUSIONS

An understanding of the fundamental principles of the development, physiology, anatomy and relationships of the maxillary sinus as depicted by multi-modality imaging is essential for radiologists reporting imaging involving the paranasal sinuses and midface.

Cone-beam computed tomography assessment of Schneiderian membranes: Non-infected and infected membranes, and membrane resolution following tooth extraction: A retrospective clinical trial

Background

Cone-beam computed tomography (CBCT) presurgical assessment on the maxillary sinus can reduce the possibility of Schneiderian membrane perforation. This study examined Schneiderian membrane thickness (SMT) and its relationship with neighboring hard tissues for patients with and without membrane thickening. For patients with sinus infections, we evaluated dimensional changes of the SMT post-extraction relative to pre-extraction SMT and residual bone height (RBH).

Methods

CBCT images from 93 patients needing single-tooth implant reconstruction without (n = 83) and with (n = 14) odontogenic infected maxillary sinuses were assessed. SMT, RBH, and lateral wall thickness (LWT) were measured. Causes of extraction, RBH in the infection site, and retrospective post-extraction record of SMT were recorded for the thickened SMT group.

Results

Mean SMT for normal SMT group was 1.13 ± 0.43 mm, RBH was 6.26 ± 2.38 mm; upper and lower LWT was 1.85 ± 0.95 mm, and 3.07 ± 2.26 mm, respectively. RBH and LWT had no significant relationships with SMT. For thickened SMT group, mean values for SMT and RBH prior to extraction were 4.53 ± 2.46 mm and 1.97 ± 1.43 mm, respectively. Pre-extraction SMT had a moderately negative correlation with pre-extraction RBH. SMT resolution in thickened SMT group was observed by 2.80 ± 1.37 months post-extraction; post-extraction SMT was not significantly different from normal SMT group (p = .187).

Conclusions

Within the limitation of the sample size, thickened SMT induced by odontogenic infection subsides about 3 months following tooth extraction, and further sinus lifting implant surgery may be considered.

Short implants (≤6 mm) versus longer implants with sinus floor elevation in atrophic posterior maxilla: a systematic review and meta-analysis

OBJECTIVES

To compare the use of short implants (≤6 mm) in atrophic posterior maxilla versus longer implants (≥10 mm) with sinus floor elevation.

DESIGN

A systematic review and meta-analysis based on randomised controlled trials (RCTs).

DATA SOURCES

Electronic searches were conducted in PubMed, Embase and the Cochrane CENTRAL. Retrospective and prospective hand searches were also performed.

ELIGIBILITY CRITERIA

RCTs comparing short implants (≤6 mm) and longer implants (≥10 mm) with sinus floor elevation were included. Outcome measures included implant survival (primary outcome), marginal bone loss (MBL), complications and patient satisfaction.

DATA EXTRACTION AND SYNTHESIS

Risks of bias in and across studies were evaluated. Meta-analysis, subgroup analysis and sensitivity analysis were undertaken. Quality of evidence was assessed according to Grading of Recommendations Assessment, Development and Evaluation.

RESULTS

A total of seven RCTs involving 310 participants were included. No significant difference in survival rate was found for 1-3 years follow-up (RR 1.01, 95% CI 0.97 to 1.04, p=0.74, I²=0%, moderate-quality evidence) or for 3 years or longer follow-up (RR 1.00, 95% CI 0.97 to 1.04, p=0.79, I²=0%, moderate-quality evidence). However, short implants (≤6 mm) showed significantly less MBL in 1-3 years follow-up (MD=-0.13 mm, 95% CI -0.21 to 0.05; p=0.001, I²=87%, low-quality evidence) and in 3 years or longer follow-up (MD=-0.25 mm, 95% CI -0.40 to 0.10; p=0.001, I²=0%, moderate-quality evidence). In addition, short implant (≤6 mm) resulted in fewer postsurgery reaction (RR 0.11, 95% CI 0.14 to 0.31, p<0.001, I²=40%, moderate-quality evidence) and sinus perforation or infection (RR 0.11, 95% CI 0.02 to 0.63, p=0.01, I²=0%, moderate-quality evidence).

CONCLUSIONS

For atrophic posterior maxilla, short implants (≤6 mm) are a promising alternative to sinus floor elevation, with comparable survival rate, less MBL and postsurgery reactions. Additional high-quality studies are needed to evaluate the long-term effectiveness of short implants (≤6 mm).

TRIAL REGISTERATION NUMBER

The protocol has been registered at PROSPERO (CRD42018103531).

Preoperative Maxillary Sinus Imaging and the Outcome of Sinus Floor Augmentation and Dental Implants in Asymptomatic Patients

OBJECTIVES

Preoperative maxillary sinus imaging findings have been suggested to be associated with complications and outcomes of sinus lift and dental implant procedures; nonetheless the evidence is controversial. The aim of this study was to examine the association between preoperative maxillary sinus imaging findings and outcomes of sinus lift and dental implant procedures in asymptomatic patients.

METHODS

We included all patients who underwent maxillary sinus lift and dental implant procedures between 2014 and 2017. Maxillary sinus imaging findings were extracted from pre-procedural dental computed tomography scans, and outcomes of the procedures were assessed.

RESULTS

A total of 145 procedures were included. No sinonasal symptoms were reported preoperatively. In 46% of cases maxillary sinus imaging was abnormal. The most common imaging finding was peripheral mucosal thickening (38%). Sinus floor cyst/polyp was identified in 13% of the cases, of which 47% occupied more than 50% of the sinus volume. Partial or complete opacification of the maxillary sinus was documented in 3% of cases. The sinus ostium and ostiomeatal complex were obstructed in 7% and 1%, respectively. Mucosal perforation was documented in 22% of cases and was inversely related to mucosal thickening (P = 0.011). Other minor post-operative complications did not correlate with radiological findings. Post-surgical sinusitis was not observed in any of the patients regardless of pre-surgical imaging findings.

CONCLUSIONS

Incidental maxillary sinus imaging findings such as mucosal swelling, cysts or polyps, regardless of their severity or size, and maxillary ostial obstruction may not need to be addressed prior to sinus augmentation and dental implant procedures in asymptomatic patients. Patients with complete sinus opacification should be referred to an otolaryngologist prior to surgery. Further controlled trials, in larger cohorts, are needed to corroborate our findings.

Osteotome Sinus Floor Elevation Without Grafting: A 10-Year Clinical and Cone-Beam Sinus Assessment

PURPOSE

To evaluate the thickness of the sinus membrane in contact with implants inserted 10 years before using an augmentation procedure without grafting material, and to identify adverse events correlated with implant protrusion in the sinus.

MATERIALS AND METHODS

Osteotome sinus floor elevations were performed without grafting material. The implants (Straumann AG, Basel, Switzerland) were placed simultaneously, all protruded into the sinus. After 10 years, implants were considered viable in the absence of mobility, pain, infection, or continued radiolucency. Sinus health was assessed using cone-beam computed tomography and by the way of a questionnaire in which patients reported symptoms of sinusitis they might have had.

RESULTS

Controlled implants (21 implants, 13 patients) were osseointegrated. The membrane thickness was <2 mm in 11 patients and 2 to 3 mm with flat thickening in 2 patients. No patients exhibited any clinical or radiographic signs of sinusitis.

CONCLUSIONS

No sinus complications were observed after 10 years. The initial protrusion of implants into the sinus did not influence long-term sinus health. The maintenance of successful integration is thus the key to avoiding sinus complication.

Potential risk factors for maxillary sinus membrane perforation and treatment outcome analysis

BACKGROUND

Most common complication of sinus floor elevation (SFE) is sinus membrane perforation (SMP).

PURPOSE

To investigate the correlation between SMP and potential risk factors and to evaluate SMP treatment outcomes.

MATERIALS AND METHODS

This study included patients who had undergone a SFE at Division of Oral Surgery and Orthodontics, Medical University of Graz from 2013 to 2017. Analysis of patients' records and CBCT focused on patient-related risk factors (sinus contours, thickness of membrane and lateral sinus wall, interfering septa, crossing vessels, former oroantral communication) and intervention-related risk factors (surgical approach, sides, number of tooth units, and sites). The outcome of SMP treatment was analyzed in the recalls.

RESULTS

In all, 121 patients underwent 137 SFE. There were 19 cases of SMP (13.9%). Two significant factors were identified: maxillary sinus contours (P = .001) and thickness of the sinus membrane (P = .005). The sinus membrane perforation rate was highest in narrow tapered sinus contours and when the sinus membrane was thinner than 1 mm. Among 19 cases with SMP, no complications were seen upon recall.

CONCLUSIONS

Maxillary sinus contours and sinus membrane thickness seem to be relevant factors for SMP. Sinus membrane perforations were successfully treated by coverage with collagen membrane.

Thickness of the Schneiderian membrane and its correlation with anatomical structures and demographic parameters using CBCT tomography: a retrospective study

Background

The aims of the present study were to determine the thickness of the Schneiderian membrane and identify the width of the maxillary sinus, which is indicated by the buccal and lingual walls of the sinus angle between. Furthermore, to investigate the possibility of a correlation between the aforementioned structures and also other anatomical and demographic parameters using CBCTs for dental implant surgical planning.

Methods

The study included CBCT images of 76 consecutive patients with field-of-view 15 × 12 or 12 × 8cm. Reformatted cross-sectional CBCT slices were analyzed with regard to the thickness of the Schneiderian membrane designated by the medial and the lateral walls of the sinus, in three different standardized points of reference. Age, gender, and position of the measurement were evaluated as factors that could influence the dimensions of the anatomical structures, using univariate and multivariate random effects regression model.

Results

The mean thickness of the Schneiderian membrane was 1.60 ± 1.20 mm. The average thickness revealed now differentiation by age (p = 0.878), whereas gender seemed to influence the mean thickness (p = 0.010). Also, the thickness of the Schneiderian membrane increased from medial to distal (p = 0.060). The mean value of the angle designated by buccal and lingual walls of the sinus was 73.41 ± 6.89 °. The angle measurements revealed no correlation with age, but a tendency towards lower mean angles in females (2.5 ° on average, p = 0.097). According to the anatomical position of the measurement, a differentiation was also detected. No correlation between thickness of the Schneiderian membrane and the angle of the walls of the sinus was concluded (p = 0.662).

Conclusions

This study demonstrated that the thickness of the Schneiderian membrane and the width of the maxillary sinus can only be affected by gender and anatomical position, but not by the age of the patient.

Evaluation of the Characteristics and Association Between Schneiderian Membrane Thickness and Nasal Septum Deviation

OBJECTIVE

Nasal septum deviation (NSD) is an anomaly that disturbs normal mucus drainage in sinuses, leading to recurrent sinusitis. Sinusitis, infections, and mucosal irritations are the potential causes of Schneiderian membrane thickening (SMT). The aim of this study was to evaluate the characteristics and association between NSD and SMT along with factors such as age, gender, and tooth groups using cone-beam computed tomography (CBCT) imaging.

METHODS

The maxillary sinus and nasal cavity of 249 patients (136 females and 113 males) were examined retrospectively using CBCT. The statistical analysis was performed to determine the association between SMT, NSD, gender, and age.

RESULTS

No statistically significant relation was detected between NSD and SMT. The NSD was found in 50.6% of patients without gender predilection. Age was not associated with the presence of NSD. The mean thickness of the membrane was least in the third molar region and highest in the first molar region. The average SMT was found to be higher in males for all the examined tooth areas (P ≤ 0.05).

CONCLUSION

A retrospective evaluation of CBCT images emphasized the concept that NSD was not a factor that affected the thickening of maxillary sinus mucosa. The CBCT imaging could be used for evaluating the maxillary sinuses and nasal septum.