Sinus Membrane Thickness Research Articles

Sinus membrane thickness of healthy endodontically treated maxillary molars

ObjectiveThe study aimed to investigate the sinus membrane thickness (SMT) adjacent to healthy endodontically-treated maxillary molars with or without protruded apical foramen into the sinus cavity using cone-beam computed tomography (CBCT).Materials and methodsImages of 207 non-smoker patients aged 18–40 were retrospectively analyzed, 140 were endodontically treated, and 136 were without endodontic treatment. Patients with any sinus pathology, teeth that have symptoms, or poor root filling were excluded. Study groups consisted of Group EM-I (endodontically treated and protruded apical foramen), Group EM-C (endodontically treated and contacted apical foramen), and similarly without endodontic treatment; Group M-I and Group M-C. SMT upon the mesial, distal, and palatal roots was measured. One-way ANOVA and Student’s t-tests were performed.ResultsGroup EM-I had the thickest sinus membrane compared to other groups (p = 0.013). SMT values were 2.37–2.60 mm in Group EM-I, and 1.34–1.58 mm in other groups. Thickening (> 2 mm) percentages were 33.45% in Group EM-I and between 4.25 and 8.25% in other groups. No statistical difference was detected between first and second molars and genders (p > 0.05).ConclusionWhen the apical foramen protruded into the sinus cavity, the conventional root canal treatment caused a minimal (between 2.37 mm and 2.60 mm) sinus membrane thickening with a rate of 33.45% based upon CBCT examinations.

A Randomized Controlled Trial Evaluating the Impact of Sinus Membrane Thickness and Sinus Dimensions on the Effectiveness of Two Graft Materials in Sinus Bone Augmentation

A Randomized Controlled Trial Evaluating the Impact of Sinus Membrane Thickness and Sinus Dimensions on the Effectiveness of Two Graft Materials in Sinus Bone Augmentation

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.

Changes in the Maxillary Sinus Membrane Thickness and Sinus Health Following Lateral Sinus Floor Elevation: Comparing Preoperative Mucosal Thicknesses of Less than and Greater than 5 Millimeters.

To investigate the effect of lateral sinus floor elevation (LSFE) on sinus membrane (SM) thickness and sinus health in mucosa thickness less and more than 5 mm. LSFE was performed in a prospective controlled clinical trial on two groups with less than and more than 5 mm (group A & B) SM thickness and followed for 6 months. Using preoperative and 6-month postoperative CBCT and clinical evaluation, SM thickness changes (primary outcome variable), sinus health, augmented bone height, and length (augmentation adequacy), membrane-related variables, and operation time were measured. Forty unilateral sinus augmentations (A:20, B:20) with simultaneous installation of 52 fixtures were performed on 40 subjects (72.5% males, mean age of 48.8±7.6). The mean preoperative and 6- month SM thicknesses in group A and group B were 1.4±0.9 and 1.3±0.6 mm, and 6.8±1.0 and 3.4±1.7 mm, respectively. The mean postoperative SM thickness significantly decreased (P<0.001) only in group B. The mean SM thickness changes also revealed a noticeable difference between the two groups (P<0.001). Augmentation adequacy and membrane perforation rate were similar in both groups. Clinical and radiographic rhinosinusitis was not detected in any of the patients. Bleeding during separation and resistance to elevation in group B were significantly higher than in group A (P=0.003, P=0.001). Surgical time in group B (12.08 ± 8.26 minutes) was longer than in group A (8.64 ± 3.70 minutes), without reaching a significant level (P=0.097). LSFE in thickened mucosa (≤10 mm) and thinner mucosa (≤5 mm) does not cause abnormal changes in the sinus membrane and sinus health. LSFE in thickened mucosa results in adequate sinus augmentation. Thickened SM also shows a significant thickness reduction. The thickened membrane does not appear to be a contraindication to SFE.

Effect of Sinus Membrane Thickness on Membrane Perforation and Bone Augmentation in Transcrestal Sinus Floor Elevation: A Retrospective Study.

Sinus membrane thickening is a common maxillary sinus disease. However, a consensus has not been reached on the effect of sinus membrane thickness on the transcrestal sinus floor elevation. This retrospective study evaluated the perforation and bone formation at transcrestal sinus floor elevation sites with different sinus membrane thicknesses. A total of 117 sites in 87 patients treated with transcrestal sinus floor elevation were included in this study. The surgical sites were divided into four groups according to the baseline sinus membrane thickness: Group A (0 to 1 mm), Group B (1 to 2 mm), Group C (2 to 4 mm), and Group D (> 4 mm). CBCT scans were taken before surgery, immediately after surgery, and 6 months after surgery. The mean baseline sinus membrane thickness was 2.16 ± 2.54 mm, and the mean residual alveolar bone height was 6.58 ± 1.85 mm. The mean endosinus new bone height was 3.76 ± 1.95 mm. The perforation rate and endosinus new bone height showed no significant difference among the groups (P > .05). The incidence rates of membrane thickening and perforation were significantly higher in smoking patients (P < .05). Membrane thickening without ostium obstruction may have little impact on transcrestal sinus floor elevation surgery in regards to perforation rate and bone formation. In addition, smoking may be a risk factor for membrane thickening, and the sinus membrane is more likely to perforate during transcrestal surgery when the patient has a history of smoking.

Cone Beam Computed Tomographic Evaluation of Schneiderian Membrane Thickness.

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). 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. 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 >6mm. Measurement and classification of sinus membrane thickness can be performed accurately with CBCT, and it is affected by age and sex factors.

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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.

Predictors of peri-implant bone remodeling outcomes after the osteotome sinus floor elevation: a retrospective study

BackgroundThis study aimed to evaluate the radiographic outcomes of implants after osteotome sinus floor elevation (OSFE), and further identify the separate predictors for these radiographic outcomes.MethodsIn this retrospective cohort study, a total of 187 implants were inserted into 138 patients using the OSFE technique. Seventy-four patients in the grafted group, and 64 patients in the non-grafted group completed this study. The vertical bone gain (VBG) and marginal bone loss (MBL) at 3 years following surgery were assessed as outcome variables. Based on extensive literature results, variables considered potential predictors of outcome variables included sex, age, tooth position, implant length, implant diameter, with or without grafting materials, residual bone height, sinus width, bone density, and sinus membrane thickness. Subsequently, the binary logistic regression analysis was applied with VBG and MBL as dependent variables, respectively. The receiver operating characteristic curve (ROC) with its area under the curve (AUC) was performed to further determine the predictive value of these predictors.ResultsOne hundred and six implants in grafted group and 81 implants in the non-grafted group were analyzed. The average VBG was 2.12 ± 1.94 mm for the grafted group and 0.44 ± 1.01 mm for the non-grafted group at 3 years (P < 0.05). The mean MBL was 1.54 ± 1.42 mm for the grafted group and 1.13 ± 1.69 mm for the non-grafted group at 3 years (P > 0.05). After the adjustment for confounders, logistic regression analysis demonstrated that implant length, grafting, residual bone height, and sinus membrane thickness were predictors of VBG. The odds ratio for VBG was 3.90, 4.04, 4.13 and 2.62, respectively. Furthermore, grafting exhibited the largest AUC at 0.80. While tooth position and implant length were predictors of MBL, the odds ratio for MBL was 3.27 and 7.85, respectively. Meanwhile, implant length exhibited the largest AUC at 0.72.ConclusionsOSFE with or without simultaneous grafting materials both showed predictable clinical outcomes. Additionally, the present study is the first quantitative and significant verification that VBG has a significant association with sinus membrane thickness, as well as residual bone height, implant length and grafting. Whereas tooth position and implant length are markedly associated with MBL.

Influence of the height of the alveolar bone in the distal parts of the upper jaw on the odontogenic inflammatory processes in the maxillary sinus

Aim: To determine whether the height of the alveolar bone affects the transmission of inflammation from the periapex of the tooth to the maxillary sinus. Background: The maxillary sinus is the largest of all paranasal cavities and is located in the body of the upper jaw. The inflammatory process in the teeth can often ascend to the maxillary sinuses and thus can cause odontogenic maxillary sinusitis. Untreated periapical inflammatory processes of the teeth in the distal parts of the upper jaw are the most common cause of odontogenic sinusitis. Data in the literature show that there is a correlation between the thickness of the mucosa of the maxillary sinus and the proximity of some anatomical structures, such as the height of the alveolar bone between the distal teeth of the upper jaw and the floor of the maxillary sinus. Methods: To accomplish the task, we analyzed 109 CBCT images of patients with odontogenic cysts of the upper jaw, located in the area below the floor of the maxillary sinus. In 61 of them the residual alveolar bone was less than 3 mm. For the other 48 it was over 5 mm. The group of teeth, included in the study, consisted of premolars and molars. Above each tooth with an odontogenic cyst, the thickness of the mucosa of the maxillary cavity was measured. For normal mucosa we considered thickness of 0 – 2 mm, and for pathological – thickness of over 2 mm. Group I – In this group we included odontogenic cysts in which the measured distance between the cystic cavity and the floor of the maxillary sinus was less than 3 mm. Group II – In this group we included odontogenic cysts in which the measured distance between the cystic cavity and the floor of the maxillary sinus was over 5 mm. Results: The following results were obtained in group I. Of the 61 cases with an odontogenic cyst present and alveolar bone height below 3 mm, the mean measured value in mm of sinus membrane thickness was 5.7 mm. The maximum value was 13 mm and the minimum was 2 mm. In group II we obtained the following results: we had 47 cases of radicular cysts of the distal teeth of the upper jaw, and the height of the bone to the floor of the maxillary sinus was 5 mm and more. The average thickness of the maxillary sinus mucosa was 2.21 mm. For comparison, up to 2 mm in the scientific literature is considered a healthy clinical mucosa. The minimum measured value was 1 mm and the maximum value was 8 mm. Conclusions: Based on the results obtained, we can conclude that there is a clear relationship between the thickening of the maxillary sinus membrane and the present periapical pathology of the maxillary distal teeth when they are close to or in contact with the floor of the maxillary sinus. This dependence increases with decreasing the volume of the residual alveolar bone.

Osteotomy in lateral sinus augmentation: A comparative study of rotary technique and Lateral Approach Sinus Kit®.

Various sinus lift techniques have been tried to minimize the rate of perforations, especially in Type I and Type II sinus membrane thickness. The aim and objectives of this study was to present our own experience compare and the efficacy of conventional direct sinus lift technique and direct sinus lift using LAS Kit. Our study included 14 patients in which seven patients in conventional technique and seven patients in Lateral Approach Sinus (LAS) Kit®. The results showed that the sinus membrane perforation rate, using LAS Kit® with specially designed drills, is less than that of the conventional technique, especially in Type I and II sinus membrane with the added benefit of reduced operative time. The mean operative time in conventional technique was 28.29 ± 2.21min and in LAS Kit®, it was 19.43 ± 2.88min which was statistically significantly less than the conventional technique group (P < 0.001). In both the groups, 100% implant integrity was achieved (measured using reverse torque technique) after 6 months of follow-up. It was observed that there was no statistically significant difference between the groups in pain, swelling, flap dehiscence, and infection at different time intervals. We conclude that the use of LAS Kit® for sinus lift procedure in atrophied maxilla with Type I and II sinus membrane is a much safer approach over the conventional technique. Further, the results obtained also showed that blood coagulum gave better gain in bone height over a period of 6 months.

Responses of Sinus Membrane and Antral Pseudocyst Following Lateral Window Sinus Augmentation with Bone Grafting: A Retrospective Study.

To investigate the influence of lateral window sinus augmentation on sinus physiology, including sinus membrane thickness and the outcome of antral pseudocysts. This retrospective study was performed by reviewing all lateral window sinus augmentation procedures, which were done between the years 2013 and 2015. Each enrolled patient had CBCT images preoperatively (T0), immediately postoperatively (T1), and 6 months postoperatively (T2). The sinus membrane thickness, pseudocyst dimensions, and intraoperative perforation were evaluated. Patient-related factors such as age and sex that could influence the mucosal properties were also analyzed. Based on established inclusion criteria, 306 patients with 320 sinuses were included in this study. The overall mean thickness of the sinus membrane (T0) was 1.30 ± 1.08 mm, and membrane thickening (> 2 mm) was observed in 22.19% of the sinuses. Preexisting pseudocysts were identified in 24 sinuses (7.50%), most of which remained unchanged or disappeared after 6 months. The intraoperative membrane perforation rate was lowest (1.96%) when the membrane thickness was 1.0 to 1.5 mm, and the perforation rate was increased in patients with thickened (> 2 mm) or thinned (≤ 1 mm) membrane. Membranes swelled immediately after operation (T1 vs T0, P < .01) and gradually recovered at 6 months. No significant change in membrane thickness was shown after the sinus augmentation procedure in the perforation group and pseudocyst group. The mean thickness of the sinus membrane at T0 and T1 was significantly higher for male subjects (P < .01). Lateral window sinus augmentation has little or no impact on sinus membrane thickness and antral pseudocysts after a 6-month healing period, except for a transient mild membrane swelling. Thickened and thinned membrane were risk factors for intraoperative perforation. Small-sized perforation and pseudocysts might not contraindicate sinus augmentation from the standpoint of the surgical impact on the sinus membrane.

Long-term effects of sinus membrane perforation on dental implants placed with transcrestal sinus floor elevation: A case-control study.

There is a little comparative data on implants placed transcrestally with/without sinus membrane (SM) perforation. To compare the clinical and radiological outcomes of implants with maxillary sinus perforation and those without SM perforation. Among 560 transcrestally placed implants in 324 patients, the patients who underwent cone-beam computed tomographic radiography (CBCT) were included. The following groups were established: implants with SM perforation (group P) and implants without SM perforation based on postoperative panoramic radiographs and patient records (group NP). Group NP was further divided into subgroups based on CBCT taken at the last patient visit: group NP1 consisting of implants with no protrusion or <1 mm of protrusion and group NP2 consisting of implants with ≥1 mm of protrusion. Mixed linear regression was performed for the factors affecting SM thickening and marginal bone loss. Mixed survival analysis was also performed. A total of 379 implants in 221 patients were eligible. The mean follow-up period was 112.03 ± 54.2months. Twenty-six implants failed (2 and 24 implants in groups P and NP, respectively), mainly due to peri-implant bone loss. No statistically significant difference was noted between the groups in SM thickness (2.4 ± 2.8 mm, 2.1 ± 3.4 mm, and 2.5 ± 3.5 mm in groups P, NP1, and NP2, respectively, p > 0.05). Marginal bone loss in group NP1 was significantly greater than that in the other groups. In the mixed model, SM perforation was not a determinant of sinus membrane thickening and implant survival in the mixed models and the survival analysis, respectively. SM perforation in transcrestal sinus augmentation did not affect implant survival and SM thickening.

Anatomical proximity of upper teeth and local factors associated with the thickness of the maxillary sinus membrane: a retrospective study

Aim: This cross-sectional study aimed to assess the proximity of root apexes to the maxillary sinus and to verify the correlation between sinus mucosal thickening with the distance from the root apex to the sinus floor, endodontic treatment, age, tooth, sex, and presence of periapical lesion. Methodology: 169 cone-beam computed tomography images were selected, and 696 teeth were assessed, 600 without endodontic treatment, and 96 endodontically treated. The images were initially classified according to the study conducted by Kwak et al. (2004) to assess the proximity of the tooth roots to the maxillary sinus, and multiple logistic regression was subsequently applied to identify probable factors influencing the thickening of the sinus mucosa. Results: The vertical relationships between tooth roots and the sinus floor among the second premolars indicated a predominance of classification I (57.7%); whereas, in the first and second molars there was a predominance of types II (48.4%) and III (34.2%), respectively. The logistic regression did not indicate significant relationships between sinus mucosal thickening and the distance from the root apexes to the sinus floor, presence of endodontic treatment, and type of tooth (p>0.05). Age, presence of periapical lesions, and sex were associated with the presence of sinus thickening (p<0.05; odds ratio=1.03, 2.99, and 5.11, respectively). Conclusions: The presence of thickening in maxillary sinuses was correlated with the following factors: age, sex, and presence of periapical lesions.

Evaluation of Sexual Dimorphism in Schneider Membrane Thickness Using Cone-Beam Computed Tomography (CBCT) for its Clinical and Forensic Implications

Sinus augmentation requires careful manipulation of the Schneider membrane. Perforation of the membrane can be a challenging complication. The objective of this study is to evaluate the sexual dimorphism of Schneider membrane (sinus membrane) using cone-beam computed tomography (CBCT) imaging modality and discuss its clinical applications vis-a-vis the sinus lift procedure for dental implants and also its forensic implications. One hundred CBCT scans in the maxillary first molar region of fifty men and fifty women in the age group of 25–50 years were examined at two standardized points on the floor and lateral wall of maxillary sinus, and its mean was obtained. Measurements were taken for thickness of sinus membrane at most prominent antero-posterior and mesio-distal dimensions. The mean sinus membrane thickness and correlation in age groups (25–35 and 36–50 years) of both the genders were evaluated statistically. The results showed a thicker sinus membrane in women, especially in 36–50 age group than that of men. This study correlates the thickness of the sinus membrane with gender dimorphism and delves on its association with the risk of perforation during sinus lift procedures and also its forensic implications.

Analysis of relationship between Haller cells and Schneiderian Membrane Thickness

Objective: This first aim of this study was to determine whether there is a relationship between the presence of Haller cells and Schneiderian membrane thickness (SMT) by considering factors such as age and gender. The second aim of this study was to investigate correlation between the visibility of Haller cells on cone beam computed tomography (CBCT) and digital panoramic radiographs. Materials and Methods: Seventy-eight edentulous patients were included in the study. Cross-sectional views obtained from CBCTs were used to determine the mean sinus membrane thickness. Parameters such as gender and age were also investigated. Results: The difference in SMT at the base of the maxillary sinus was significant between those with and without Haller cells (p &amp;lt;0.05). A correlation was found between the detection of Haller cells on CBCT and digital panoramic radiographs (p &amp;lt;0.01). Although SMT was higher in men than in women, this difference was not significant (p&amp;gt; 0.05). Conclusion: Considering the results of our study, the presence of Haller cells may cause sinus membrane thickness at base of maxillary sinus. Since Haller cells can also be seen in digital panoramic radiographs, digital panoramic view taken prior to sinus lift surgery can provide clinicians with preoperative hint about SMT.

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

BackgroundDuring 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).ResultsWe 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).ConclusionsFactors 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.

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.

Possible risk factors of sinus membrane perforation during sinus floor elevation: A retrospective study

Aim: To investigate risk factors causing sinus membrane perforation during sinus floor elevation (SFE) performed with lateral window technique and to evaluate the sinus membrane health after SFE via Cone-Beam Computed Tomography (CBCT). Materials and Methods: CBCT images of 33 patients with sinus membrane perforation during SFE and 33 patients without perforation during SFE as a control and a total of 80 CBCTs were evaluated. Patient-related factors (age, sex, smoking) and maxillary sinus-related factors (preoperative membrane thickness, residual bone thickness, postoperative membrane thickness, and postoperative total bone thickness, type of sinus membrane morphology, and presence of septa) were assessed. Results: Preoperative sinus membrane thickness of the perforated group (4.38 ± 6.02 mm) was significantly higher than the non-perforated group (1.74 ± 2.81 mm) (p = 0.02). No significant difference was found between preoperative and postoperative membrane thicknesses of the non-perforated and perforated group (p = 0.135 and p = 0.106, respectively). The perforation rate was highest (83.3%) in the group of mucosal thickness ≥4 mm. Membrane perforation was observed in 100% of circumferential and complete type sinus membrane morphology, 80% of polyp type morphology, and 85.7% in irregular type morphology. A relationship was found between the presence of septa and membrane perforation (p = 0.01). Conclusion: The study results show that the presence of septa, age of >55 years, and a sinus membrane thickness of >4 mm are associated with an increased risk of sinus membrane perforation. Perforation did not affect postoperative sinus membrane thickness.

Radiography study on osteotome sinus floor elevation with placed implant simultaneously with no graft augmentation

OBJECTIVE To investigate the change of endo-sinus bone height and bone volume in osteotome sinus floor elevation (OSFE) without bone graft but placing implants simultaneously by using cone beam computed tomography (CBCT) and three dimensional analysis, and to find the impacting factors on endo-sinus bone augmentation. METHODS OSFE was performed in 38 edentulous patients with missing teeth at posterior maxillary region, and 44 implants were placed and referred for OSFE using no graft materials. CBCT was performed pre-surgery and 9－68 months post-surgery when the patients encountered another implant surgery. The gained bone height at mesial, distal, buccal and palatal sites around the implant in sinus were measured, volumetric measurements of the endo-sinus gained bone volume (ESGBV) in the elevated region were calculated by Mimics software. Univariate analysis and multiple linear regression were performed to investigate the impacting factors on the gained bone height and ESGBV. Marginal bone loss was recorded according to the periapical radiography after implant restoration. RESULTS The mean residual bone height (RBH) pre-surgery was (3.41±1.23) mm, the mean protruded length (PL) into sinus of implant post-surgery was (3.41±1.28) mm, the mean endo-sinus gained bone height was (2.44±1.23) mm at distal sites, (2.88±1.20) mm at mesial sites, (2.83±1.22) mm at buccal sites and (2.96±1.16) mm at palatal sites, the mean endo-sinus gained bone height at distal sites was significantly lower than the other three sites (P < 0.05). The average endo-sinus gained bone height was (2.78±1.13) mm. The mean ESGBV was (122.15± 73.27) mm3. Univariate analysis showed the more RBH, the less bone height gained in sinus, which existed at buccal, lingual, mesial and distal sites (P < 0.001), and the more RBH, the smaller ESGBV gained (P=0.012). The ESGBV was significantly higher in the subjects whose bone generation period was more than 24 months than those whose bone generation period less than 24 months (P=0.034). The more PL, the more bone height and ESGBV gained (P=0.008). Multivariate analysis showed after adjusting factors of gender, age, smoking, width of sinus floor, thickness of sinus membrane pre-surgery, diameter and length of the implant, PL and bone generation period was positively correlated with mean endo-sinus gained bone height and ESGBV, while RBH negatively correlated with mean endo-sinus gained bone height. During the follow-up, the mean marginal bone loss was 0 (0－1.41) mm and all the implants loaded successfully. CONCLUSION OSFE without bone graft but with placed implant simultaneously can increase endo-sinus gained bone height and ESGBV. RBH, PL and bone generation period are the significant factors impacting endo-sinus bone augmentation.

Evaluation of the maxillary sinus anatomical variations related to maxillary sinus augmentation using cone beam computed tomography images

ObjectiveThe purpose of this study was to evaluate the anatomical characteristics of the maxillary sinus and their association with sex, age, and dental status using cone beam computed tomography images (CBCT). MethodsThis was a retrospective study using CBCT images of maxillary sinuses from 370 sinuses in 185 patients. The following anatomical structures were evaluated: (1) Residual ridge height (RRH), (2) Lateral wall thickness (LWT), (3) Maxillary sinus septa, (4) Sinus membrane thickness (MT), and (5) Ostium. These anatomical structures were compared based on sex, age, and dental status. ResultsMean RRH was 12.13 ± 3.64 mm. Mean LWT was 2.23 ± 0.95 mm. The septa prevalence were 22.43 %. The typical orientation of the septa were mediolateral (89.13 %). The septa were commonly at the middle region (66.3 %). Mean MT was 1.3 ± 2.05 mm. The ostium was most located at the middle region (95.98 %). Mean distance of the ostium from the sinus floor was 30.03 ± 5.08 mm. The sex, age, and dental status results indicated that females had a greater RRH than males; Males had a thicker LWT, thicker MT, and higher distance of the ostium; the dentate group had a greater RRH, thicker LWT, and higher distance of the ostium; the elderly had a lower RRH, thinner LWT, thicker MT, and lower distance of the ostium. ConclusionsDue to the anatomical variations in the maxillary sinus, it should be evaluated before surgery. We recommend using CBCT in planning the surgery, to minimize the risk of complications related to sinus surgery.