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

Ridge Preservation Combined With Open Barrier Membrane Technique in Case of Postextractive Oroantral Communication: A Case Series Retrospective Study

After dental extraction, a physiological phenomenon of reabsorption of the dentoalveolar process is triggered, especially if periradicular lesions are present, which can sometimes be associated with oroantral communication in the upper posterior maxilla. To investigate a minimally invasive approach, 19 patients undergoing tooth extraction in the posterosuperior maxilla were recruited. All cases presented an oroantral communication with a diameter of 2-5 mm after tooth extraction and the alveolar process and, in some cases, with a partial defect of 1 or more bony walls. In these cases, a single surgical procedure was used to preserve the alveolar ridge using an open barrier technique with an exposed dense polytetrafluoroethylene membrane. The bottom of the extraction socket was filled with a collagen fleece. The residual bone process was reconstructed using a biomaterial based on carbonate-apatite derived from porcine cancellous bone. After 6 months, all patients were recalled and subjected to radiographic control associated with an implant-prosthetic rehabilitation plan. Data relating to the sinus health status and the average height and thickness of the regenerated bone were collected. Radiographic evaluation verified the integrity of the maxillary sinus floor with new bone formation, detecting a vertical bone dimension between 3.1 mm and 7.4 mm (average 5.13 ± 1.15 mm) and a horizontal thickness between 4.2 mm and 9.6 mm (average 6.86 ± 1.55 mm). The goal of this study was to highlight the advantage of managing an oroantral communication and, simultaneously, obtain the preservation and regeneration of the alveolar bone crest. The open barrier technique appears to be effective for the minimally invasive management of oroantral communication up to 5 mm in diameter in postextraction sites, with a good regeneration of hard and soft tissue.

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.

Cone Beam Computed Tomographic Evaluation of Schneiderian Membrane Thickness

OBJECTIVE

This study aimed to determine the measurements and classification of Schneider membrane thickness correlated to age and sex factors using cone beam computed tomography (CBCT).

METHODS

The study included CBCT images for 100 maxillary sinuses of 50 consecutive patients, and the thickness of the maxillary sinus membrane (Schneiderian membrane) was measured in coronal view from the lowest point in the floor of the maxillary sinus to the highest point. The thickness of the Schneiderian membrane was classified into 4 types.

RESULTS

The study result revealed that out of the total cases, 45% of sinus membranes were classified as type 2, while only 10% were classified as type 4. The most frequent type of membrane thickness diagnosed in the age group 20 to 30 as type 1, whereas in age groups 31 to 40 and 41 to 50, regarding sex, type 4 was more obvious in males with membrane thickening >6 mm.

CONCLUSIONS

Measurement and classification of sinus membrane thickness can be performed accurately with CBCT, and it is affected by age and sex factors.

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.

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.

Efficacy of mucolytics and steam therapy in the management of sinusitis among Indians

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.

Clinical, radiographic characterizations and complications of maxillary molar in a periodontitis population: a retrospective study based on CBCT radiography

OBJECTIVE

This study was aimed to delineate the clinical, CBCT radiographic characteristics, and complications of maxillary molar in a periodontitis population.

MATERIALS AND METHODS

Medical records and CBCT images were utilized to identify adult patients with periodontitis in a tertiary referral dental hospital between June 2019 and December 2020. CBCT scan images were used to characterize the detailed bone thickness, absorbing height, and position of maxillary molar as well as their associated conditions. All relevant descriptive epidemiological data, clinical information, radiographic details, and associated complications were recorded and statistically analyzed.

RESULTS

According to the above criteria, 577 eligible periodontitis patients were enrolled and defined as research cohort here with mean age 45 ± 4.8 years. Male patients outnumbered females with a gender ratio of 1.23:1. Our results demonstrated that the bone loss of maxillary first molar was more serious than that of second molar with tooth position symmetry. The occurrence of various complications (periodontal abscess, pulp lesions, furcation lesion, and mucosal thickening) was significantly correlated to periodontal-related clinical parameters of maxillary molar.

CONCLUSIONS

Our results demonstrated the more serious bone loss of maxillary first molar with tooth position symmetry. The occurrence of various complications was significantly correlated to periodontal-related clinical parameters. Our findings offer valuable information concerning the clinical, radiographic characteristics, and complications of maxillary molar in a periodontitis population.

CLINICAL RELEVANCE

These findings are beneficial for clinicians to comprehensively understand the bone status, pathogenesis, and clinical management of maxillary molar in periodontitis.

Anatomical variations and accessory structures in the maxilla in relation to implantological procedures: an observational retrospective study of 212 cases using cone-bean computed tomography

PURPOSE

This study used cone-beam computed tomography (CBCT) to analyze the prevalence of several maxillary anatomical/accessory structures, as well as variations within each type, assessing how accurate diagnosis can minimize the risk of intraoperative complications during implantological procedures in the oral cavity.

METHODS

212 CBCT scans of the maxilla were analyzed, captured over a period of 18 months for surgical planning purposes. The prevalence of posterior superior alveolar arteries (PSAA), maxillary sinus septa (MSS), and branches of the canalis sinuosus (CS) were evaluated, as were the diameter and location of each anatomical structure in horizontal and vertical planes. P < 0.05 was considered statistically significant.

RESULTS

PSAAs were observed in 99.1% of cases, the intrasinus type being the most frequent; MSS were noted in 15.6% of the sample, mainly in the posterior region with sagittal orientation; CS branches were observed in 50% of patients, mainly in relation to the incisors and significantly more prevalent among males.

CONCLUSIONS

The use of CBCT significantly increases the possibility of clearly identifying these anatomical structures. The differences found between patients highlight the importance of carrying out an exhaustive radiological study of the individual to prevent complications, such as Schneiderian membrane perforation, neurovascular damage or bleeding during surgery.

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.

Management of Schneiderian membrane perforations during maxillary sinus floor augmentation with lateral approach in relation to subsequent implant survival rates: a systematic review and meta-analysis

BACKGROUND

This systematic review aimed to propose a treatment protocol for repairing intraoperative perforation of the Schneiderian membrane during maxillary sinus floor augmentation (MSFA) procedures with lateral window technique. In turn, to assess subsequent implant survival rates placed below repaired membranes compared with intact membranes and therefore determine whether membrane perforation constitutes a risk factor for implant survival.

MATERIAL AND METHODS

This review was conducted according to PRISMA guidelines. Two independent reviewers conducted an electronic search for articles published between 2008 and April 30, 2020, in four databases: (1) The National Library of Medicine (MEDLINE/PubMed) via Ovid; (2) Web of Science (WOS); (3) SCOPUS; and (4) Cochrane Central Register of Controlled Trials (CENTRAL); also, a complementary handsearch was carried out. The Newcastle-Ottawa Quality Assessment Scale was used to assess the quality of evidence in the studies reviewed.

RESULTS

Seven articles fulfilled the inclusion criteria and were analyzed. A total of 1598 sinus lift surgeries were included, allowing the placement of 3604 implants. A total of 1115 implants were placed under previously perforated and repaired membranes, obtaining a survival rate of 97.68%, while 2495 implants were placed below sinus membranes that were not damaged during surgery, obtaining a survival rate of 98.88%. The rate of Schneiderian membrane perforation shown in the systematic review was 30.6%. In the articles reviewed, the most widely used technique for repairing perforated membranes was collagen membrane repair.

CONCLUSIONS

Schneiderian membrane perforation during MFSA procedures with lateral approach is not a risk factor for dental implant survival (p=0.229; RR 0.977; 95% CI 0.941-1.015). The knowledge of the exact size of the membrane perforation is essential for deciding on the right treatment plan.

Effect of ridge preservation at molar extraction sites with severe periodontitis on the Schneiderian membrane thickness changes: a pilot study

Background

Information regarding the reaction of bone augmentation in terms to sinus mucosa thickness of periodontally compromised molar extraction sites is limited. This retrospective study aimed to analyze the effect of ridge preservation procedures following the extraction of molars with severe periodontitis on the healing pattern of adjacent maxillary sinus mucosal membranes.

Methods

Thirty-one periodontally compromised maxillary molar teeth either receiving ridge preservation (test group, n = 20) or undergoing spontaneous healing (control group, n = 11) were investigated. Cone-beam computed tomography (CBCT) scanning was performed before the extraction procedure and repeated 6 months later. The mucosa thickness (MT) of the adjacent periodontally compromised molar tooth was measured from CBCT images before tooth extraction and after 6 months of healing at nine assigned measurement points. The data were analyzed at α = 0.05.

Results

The prevalence of pre-extraction maxillary sinus mucosal thickening was 60.0% and 63.6% in the test and control groups, respectively. The average MT of the thickened sinus mucosa before tooth extraction was 3.78 ± 2.36 mm in the test group and 4.63 ± 3.20 mm in the control group (P = 0.063). The mean mucosal thickening reductions in the thickened MT subjects after 6 months of healing were 2.20 ± 2.05 mm (test group) and 2.64 ± 2.70 mm (control group), P = 0.289. The differences of MT between the time prior to extraction and after 6 months of healing were statistically significant within both groups (P < 0.05).

Conclusions

Following extraction of molars with severe periodontitis, a reduction in swelling of the Schneiderian membrane has been observed regardless of the addition of a DBBM socket graft. However, a mucosal thickness > 2 mm was still frequently observed.

Thickening of Schneiderian membrane secondary to periapical lesions: A retrospective radiographic analysis

Aim:

The aim of this study was to investigate the possible correlation between adjacent periapical lesions of maxillary teeth and Schneiderian membrane thickness (SMT).

Materials and Methods:

An analytical study of case-control study design was conducted. From the archives, cone beam computed tomography (CBCT) images of 83 patients with periapical lesion in any of the maxillary posterior teeth were randomly selected as the case group. The normal, contralateral teeth in the same patient were considered in the control group. Eighty-eight teeth were considered in each group, comprising a total sample of 176. For each sample in case group, the distance from the border of the periapical lesion to the cortical bone of the bony floor of the maxillary sinus and SMT were measured. SMT on the contralateral side adjacent to the healthy (control) teeth was also measured. Data were presented in mean ± standard deviation and inferential statistics was performed using independent t test and analysis of variance (ANOVA). Later Pearson correlation and multiple linear logistic regression were carried out using Statistical Package for the Social Sciences software program, version 21.0 at 95% confidence interval.

Results:

Teeth with periapical lesion were found to have significantly (P < 0.001) increased SMT when compared with that of adjacent to healthy teeth. On the contrary, nonsignificant differences were found in SMT when genders and age groups were compared (P = 0.295 and 0.060, respectively). A strong negative correlation was observed between distance of the lesion to the sinus and SMT (P = 0.003).

Conclusion:

Neighboring periapical lesions of maxillary teeth are associated with SMT that is worsened when the lesion is close to the sinus.

Periapical Lesions and Their Relationship to Schneider's Membrane in Cone-Beam Computed Tomography

Objective

To determine the relationship between the height of the periapical lesions adjacent to the maxillary sinus and the thickness of the Schneider membrane evaluated with cone-beam tomography. Materials and Methods. The universe was made up of 2432 tomography scans and a sample of 976, by systematic random sampling, and took into account those that presented any of the variables and/or both. For the relationship analysis, the sample was distributed according to sex, maxillary side, and age; it was formed between 18 and 86 years, in age groups of 18–36 years, 37–48 years, 49–59 years, and 60–86 years. The quantitative variables of the statistic descriptive analysis, hypothesis tests, and Spearman correlation were recorded.

Results

A significantly low correlation (p < 0.010) was observed between the periapical lesions and the thickness of the Schneider membrane in women (rho = 0.38) and men (rho = 0.32); in the same way, a significantly low correlation was observed in the age groups of 18–36 years (rho = 0.27) and 37–48 years (rho = 0.28), while a significantly moderate correlation was observed in the age groups of 49–59 years (rho = 0.45) and 60–86 years (rho = 0.44), and with respect to the sides, a significantly low correlation (rho = 0.28) was obtained for the right side and a significantly moderate correlation (rho = 0.45) was obtained on the left side.

Conclusion

We found that the height of the periapical lesions and the thickness of the Schneider membrane are significantly related according to age, sex, and maxillary side, this relationship being accentuated at an older age and on the left side.

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.