Antral computerized tomography pre-operative evaluation: relationship between mucosal thickening and maxillary sinus function

Characterization of the Maxillary Sinus Using Cone Beam Computed Tomography. A Retrospective Radiographic Study

PURPOSE

To analyze the anatomical findings and alterations of the maxillary sinus in asymptomatic patients observed by cone beam computed tomography.

MATERIALS AND METHODS

A cross-sectional retrospective study of the anatomical variations and alterations of the maxillary sinus was made in 160 patients-71 males (44.3%) and 89 females (55.6%), with an age range of 18 to 74 years-measuring the thickness of the Schneiderian membrane and the cortical thickness of the lower margin of the maxillary sinus (in its most caudal portion), and correlations among the different study variables were assessed.

RESULTS

Sinus pneumatization was the most frequent anatomical finding (81.3%). A negative correlation was observed between the thickness of the Schneiderian membrane and the presence of Underwood septa (P < 0.005). Mucosal thickening of more than 2 mm was directly correlated with the presence of maxillary sinus lesions (opacification, discontinuity of the floor of the sinus, polypoid lesions, or air-liquid levels).

CONCLUSION

The presence or absence of septa seems to be related to the thickness of the Schneiderian membrane.

Three-Dimensional Evaluation of Maxillary Sinus Septa for Implant Placement

Background

The aim of our study was to investigate, in 3 dimensions, the maxillary sinus septa as an alternative site for dental implant placement to avoid sinus lift procedures.

Material/Methods

We selected 100 dentate and 100 edentate patients with the presence of a maxillary sinus septum by reviewing a larger cone beam computer tomography (CBCT) database from the Department of Oral and Maxillofacial Surgery at Cliniques Universitaires Saint Luc in Bruxelles, Belgium.

Three-dimensional reconstructions of 200 maxillary sinus septa were performed using Maxilim software. Ten measurements (length, lateral height, and thickness of the middle and medial region of the septum) were performed by 1 observer, 2 times, with an interval of 1 week between measurements. The angle between the septum and the maxillary plane was also measured. Finally, localization and orientation were assessed for each septum.

Results

There was no statistically significant difference between the 2 intraobserver measurements (p>0.05).

Student’s t-test was used to compare means. Middle height was the only measurement for which there was a difference between edentate and dentate patients (p=0.0095, edentate mean < dentate mean).

The location of the septa observed in our study groups demonstrated greater prevalence in the posterior region than in the anterior and middle regions. For the spatial orientation of the septum, we found that most septa (81.2% in dentate patients, 53% in edentate patients) were oblique.

Conclusions

Three-dimensional evaluation of maxillary sinus septa using 3D CBCT imaging showed that the sinus septum could offer an alternative site for implant placement in the maxillary sinus.

Dental implants and grafting success remain high despite large variations in maxillary sinus mucosal thickening

Background

Although mucosal thickening is the most common radiographic finding observed regarding sinus pathology, the knowledge regarding its clinical significance on the outcomes of dental implants and grafting in the maxillary sinuses is still limited. We hypothesized that mucosal thickening would not alter the predictability for sinus floor augmentation and dental implant placement. The purpose of this retrospective study was to evaluate the outcomes of dental implant placement in sinus-augmented areas with preexisting sinus mucosal thickening.

Methods

This study involved the review of cone-beam computed tomographic (CBCT) scans taken on patients that underwent both maxillary sinus elevation with grafting and implant placement at the University of Michigan School of Dentistry from 2004 to 2014. Cases with documented radiographic and clinical follow-up were included. The data analyses revealed the following.

Results

A total of 29 CBCT scans met the inclusion criteria for evaluation, and 93.1% of them had maxillary sinus mucosal/tissue thickening. Specifically, 6.9% of cases exhibited no thickening, 6.9% had minimal thickening (1–2 mm), 20.7% of cases had moderate thickening (2–5 mm), and 65.5% had severe thickening (>5 mm). We propose these categorical measurements of tissue thickening as a new “mucosal thickening index.” The tissue thickening did not vary based on gender, age, or smoking status, nor did it relate to the underlying alveolar ridge height. However, patients with a history of periodontal diseases demonstrated a significant association with mucosal thickening (p = 0.0043). These data indicate that there is high implant and grafting success rate (100%) in the maxillary sinus despite large and varied physiologic sinus mucosal/tissue thickening.

Conclusions

Based on study findings, this research will help guide dental practitioners regarding cases that exhibit mucosal thickening. These data support the concept that physiologic mucosal thickening in varied ranges is not associated with implant or grafting failure in the maxillary sinus.

Radiological Study of Maxillary Sinus using CBCT: Relationship between Mucosal Thickening and Common Anatomic Variants in Chronic Rhinosinusitis

INTRODUCTION

Inflammatory diseases of the maxillary sinus favour the thickening of the sinus mucosa. Therefore, it might be possible to establish a radiological, pathological threshold of mucosal thickening. Furthermore, there is an association between common anatomic variants of the nose and maxillary mucosal thickening.

AIM

To define the pathological thickening of maxillary sinus mucosa and its association with the presence of common anatomic variants (concha bullosa, Haller's cell and accessory maxillary ostium).

MATERIALS AND METHODS

From March 2014 to February 2016, Two hundred patients underwent Cone Beam Computed Tomography (CBCT) of the paranasal sinus. We conducted this retrospective study of total 70 patients, 34 patients i.e., a total of 68 meatus-maxillary units (study group - those affected by Chronic Rhinosinusitis (CRS) and another 36 patients i.e., a total of 72 meatus maxillary units (control group - without symptoms of CRS). We assessed the degree of thickening of the sinus mucosa distinguishing between ≥ 2mm or ≤ 2mm, than we analysed the behaviour of the thickness in the study group and in the control group. Chi-Square test was used to compare mucosal thickening between study and control group and the presence of some common anatomic variants or closure of maxillary ostium.

RESULTS

In the study group we observed a clear association between maxillary mucosal thickening ≥ 2mm and CRS (p<0.01). We however, observed no association between the presence of common anatomic variations and thickening of the maxillary mucosa and between the presence of common anatomic variations and the study group. Instead, using a binary logistic regression, we observed a significant association (p<0.01) between closure of natural ostium of the maxillary sinus and mucosal thickening or between closure of natural ostium and study group.

CONCLUSION

We believe that a thickening of the maxillary mucosa ≥ 2mm and closure of natural maxillary ostium are statistically associated with CRS. The common anatomical variants do not seem to be associated with this condition.

Do periapical and periodontal pathologies affect Schneiderian membrane appearance? Systematic review of studies using cone-beam computed tomography

OBJECTIVES

This systematic review analyzed the relationship between periapical and periodontal pathologies in the posterior maxilla and the appearance of the Schneiderian membrane in cone-beam computed tomography (CBCT) compared with sound dentitions.

METHODS

Five electronic databases (Cochrane Library, Embase, OpenGrey, PubMed, Web of Science), complemented by hand searching, were screened up to May 9, 2016. Human clinical studies that used CBCT and contained information on the periapical/periodontal status in the posterior maxilla and Schneiderian membrane appearance were included. A weighted vote counting (WVC) method was applied to summarize results across studies.

RESULTS

Out of 413 records, 20 studies were included. In the WVC, the studies that observed a positive association between periapical lesions and the appearance of the Schneiderian membrane outweighed those that found no such association (WVC 51 % and WVC 33 %, respectively), with some studies yielding indeterminate results (WVC 16 %). Regarding the relation between periodontal pathologies and the appearance of the Schneiderian membrane, WVC produced a tie between studies demonstrating a positive association (WVC 46 %) and those showing no association (WVC 44 %); one study (WVC 10 %) reported indeterminate results.

CONCLUSIONS

On CBCT scans, periapical lesions in the posterior maxilla are likely to be associated with Schneiderian membrane thickening. In contrast, current evidence regarding the relation between periodontal diseases and the appearance of the Schneiderian membrane in CBCT is inconclusive.

CLINICAL RELEVANCE

Incidental maxillary sinus findings on CBCT scans warrant thorough differential diagnosis. Frequently, they may be related to dental pathologies.

Incidental paranasal sinusitis on routine brain magnetic resonance scans: association with atherosclerosis

BACKGROUND

Incidental paranasal sinusitis (IPS) is common on imaging for non-sinusitis disorders, usually without symptoms or obstructive features, and possibly arising from periodontitis (PD). PD associations with atherosclerosis have been widely reported. We test if IPS may also be associated with atherosclerosis.

METHODS

IPS was scored retrospectively in a random sample of 180 magnetic resonance (MR) brain scans and compared with chart review for atherosclerosis (all subtypes), rhinosinusitis, and related factors (smoking, asthma, and relevant surgery). IPS was scored out of 30, from all sinuses, with maxillary sinuses weighted double volumetrically. Significant IPS (Sig IPS) was designated as 6 or more out of 30. Bivariate logistic regression was used to test for associations of Sig IPS to the clinical data, with multivariate analysis then testing for potential confounders.

RESULTS

A total of 173 subjects were analyzed (7 exclusions). MR indications included suspected acute/prior stroke (22.0%). Sig IPS found in 20 (11.6%). Positive histories for atherosclerosis were cerebral, 57 (32.9%); coronary, 48 (27.7%); and peripheral arterial disease, 14 (8.1%). IPS ≥6 was strongly associated with cerebrovascular disease (odds ratio [OR] 6.0, p < 0.001), and less robustly to smoking (OR 2.9, p = 0.07) and rhinosinusitis (OR 2.4, p = 0.09). No associations with coronary or peripheral artery diseases were found. After controlling for smoking and rhinosinusitis, yielding significant subclinical sinusitis, the link of Sig IPS to cerebrovascular disease persisted (modified OR 5.2, p = 0.002).

CONCLUSION

Significant incidental sinusitis, which is mostly subclinical sinusitis, is associated with cerebrovascular disease but not other atheroscleroses. This suggests possible common causation of both by PD.

Association between Odontogenic Conditions and Maxillary Sinus Disease: A Study Using Cone-beam Computed Tomography

INTRODUCTION

The maxillary sinus can be affected by dental infections because of its close relationship with upper teeth. This study aimed to assess the most common types of maxillary sinus alterations and to associate them with odontogenic conditions using cone-beam computed tomographic (CBCT) images.

METHODS

CBCT scans of 400 patients showing sinus disease in 1 or both maxillary sinuses were evaluated. Sinus alteration was considered as follows: generalized or localized mucosal thickening (MT), maxillary sinusitis (MS), and retention cysts (RCs). The odontogenic conditions evaluated were inadequate endodontic treatment, periapical lesions, and periodontal bone loss. Descriptive and multiple logistic regression analyses were performed.

RESULTS

Sinus diseases were observed in 85.9% of the maxillary sinuses. The most prevalent condition was generalized MT (65.2%) followed by localized MT (24.8%), MS (6.4%), and RCs (3.6%). Generalized MT was more related to males (odds ratio = 1.45, P < .05) and periodontal bone loss (P < .05). Localized MT was associated with periapical lesions (odds ratio = 3.09, P < .05) and showed a close anatomic relationship between teeth and the sinus floor (odds ratio = 2.77, P < .05). There were no statistically significant associations between either MS or RCs and the odontogenic conditions studied.

CONCLUSIONS

The most prevalent sinus diseases were the generalized and localized MT, and they were the only ones related to odontogenic conditions (periodontal bone loss and periapical lesions, respectively). We emphasize that CBCT imaging is an appropriate method for evaluating the maxillary sinus findings and their associated odontogenic conditions.

Schneiderian Membrane Thickness and Clinical Implications for Sinus Augmentation: A Systematic Review and Meta-Regression Analyses

BACKGROUND

Schneiderian membrane thickness (SMT) has been regarded as a key factor for influencing membrane perforation, which may jeopardize the final clinical outcome of sinus augmentation. Hence, this systematic review aims at studying the mean SMT and further investigating patient-related factors that may affect SMT. As a secondary goal, the association between SMT and membrane perforation rate was studied.

METHODS

Three independent reviewers in several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register databases, conducted electronic and manual literature searches. This review was written and conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and MECIR (Methodological Expectations of Cochrane Intervention Reviews) guidelines. Quantitative assessment was performed for articles that met the inclusion criteria to investigate the mean SMT, its contributing factors, and the influence on membrane damage and surgical complications.

RESULTS

Thirty-one studies that reported maxillary SMT were considered for qualitative analysis. Nineteen were further meta-analyzed. Overall mean ± SE SMT was 1.17 ± 0.1 mm (95% confidence interval [CI] = 0.89 to 1.44). Although mean SMT for the three-dimensional radiography (3DR) group was 1.33 mm (95% CI = 1.06 to 1.60), for the histology group, it was 0.48 mm (95% CI = 0.12 to 1.1). Random-effects model showed that, although there is a trend for thicker SMT as determined using 3DR compared with histologic analysis, such difference did not reach statistical significance (P = 0.15). Also, regression analyses demonstrated that the variables periodontitis (P = 0.13) and smoking (P = 0.11) showed thicker SMT. Inconclusive data were obtained when correlating SMT and perforation rate, although it seems that thicker SMT might be more prone to perforation (P = 0.14).

CONCLUSIONS

SMT is, on average, 1 mm in patients seeking sinus augmentation. Three-dimensional technologies overestimate approximately 2.5 times SMT when compared with histologic analysis. Periodontitis and smoking may result in thickening of the sinus membrane. However, current data were inconclusive to link SMT to the rate of membrane damage.

Influences of Schneiderian membrane conditions on the early outcomes of osteotome sinus floor elevation technique: a prospective cohort study in the healing period

OBJECTIVES

To radiographically investigate early outcomes of osteotome sinus floor elevation in the healing phase utilizing cone beam computed tomography and evaluate influences of Schneiderian membrane conditions.

MATERIAL AND METHODS

One hundred patients were consecutively recruited for osteotome sinus floor elevation (OSFE) surgery using deproteinized bone mineral. CBCT was taken prior to (T0), immediately post-operatively (T1), and after the healing period (T2). Linear and volumetric measurements of the elevated region from T0 to T1 were performed for evaluation on computed tomography (CT).

RESULTS

Osteotome sinus floor elevation were performed in 100 patients. One implant of each patient was selected. Mean residual bone height (RH) was 7.21 ± 1.12 mm. Mean sinus floor elevation height (SE) was 4.81 ± 0.75 mm. The mean endo-sinus bone gain after the healing period was 3.25 ± 0.83 mm. Pre-opterative CBCT scans revealed that 72 patients had a normal sinus membrane in osteotome region, 13 patients presented with flat thickened mucosa and 15 patients with antral pseudocysts. There is no significant difference in sinus mucosa elevation height, bone graft volume and new bone formation in group of Thickening membrane and Antral pseudocysts compared with normal.

CONCLUSIONS

The radiographical results show that OSFE is a safe and predictable surgical procedure in residual bone height of 7.21 ± 1.12 mm. Mild flat thickening (>2 and <5 mm) and antral pseudocysts in a small size without clinical symptoms may not be contraindications to OSFE surgery.

Association between maxillary sinus pathologies and healthy teeth

INTRODUCTION

The proximity of the roots to the maxillary sinus can create a variety of risks.

OBJECTIVE

To evaluate the relationship between the roots of healthy teeth and the maxillary sinus, as well as the occurrence of sinus pathologies.

METHODS

Three radiologists analyzed 109 cone beam computed tomography (CBCT) images. The Kappa test was used to assess the intra- and inter-rater agreement. The chi-squared test and prevalence ratio were used to test the hypothesis that roots of healthy teeth in the maxillary sinus favored the occurrence of sinus pathologies (p=0.01).

RESULTS

Intra- and inter-rater agreement ranged from good to excellent. The chi-squared test demonstrated a statistically significant difference (p=0.006) between the tooth roots in diseased maxillary sinuses (6.09%) and those in normal sinuses (3.43%). The prevalence ratio test showed a statistically significant higher prevalence of tooth roots in diseased sinuses than in normal sinuses (p<0.0001). Roots in the maxillary sinus were 1.82 times more associated with diseased sinuses.

CONCLUSION

Dental roots in the maxillary sinus are almost twice as likely to be associated with diseased sinuses than normal sinuses. Healthy teeth whose roots are inside the maxillary sinus may induce an inflammatory response in the sinus membrane. It is suspected that dental procedures may exacerbate the condition.

Longitudinal response of membrane thickness and ostium patency following sinus floor elevation: a prospective cohort study

OBJECTIVES

To investigate the influence of sinus floor elevation (SFE) on sinus physiology, including Schneiderian membrane thickness (MT) and ostium patency, using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

Based on pre-established selection criteria, 53 patients in combination with 53 sinuses were referred for SFE with a lateral approach using deproteinized bone mineral. CBCT was performed prior to, immediately after surgery and before staged implant placement. The Schneiderian MT of the elevated region, ostium patency, and other clinical data was evaluated.

RESULTS

The two-stage sinus augmentation technique was applied in 33 males and 20 females. Four membrane perforations were observed during the surgical procedure. The Schneiderian membrane exhibited significant swelling immediately after augmentation (P < 0.0001), but this difference disappeared after a mean healing period of 7.51 months. The corresponding changes were also observed for ostium patency with a tendency of transient obstruction after surgery. Sinuses with flat mucosal thickening or pseudocysts did not present a liability of perforation compared to the normal cases, and the augmentation procedure was not likely to deteriorate the pathology of mucosal thickening or pseudocysts.

CONCLUSIONS

The results show that SFE with a lateral approach has no significant influence on MT and ostium patency after the healing period except for postoperative transient swelling and obstruction. Thickened membranes and antral pseudocysts in a small size might not be contraindications to SFE from the standpoint of the surgical impact on the Schneiderian membrane.

IRAK4 gene polymorphism and odontogenic maxillary sinusitis

Objectives

This study aimed to evaluate whether a specific interleukin-1 receptor-associated kinase-4 (IRAK4) gene polymorphism had any influence on the development of changes in maxillary sinus, particularly in the presence of etiological factors of dental origin.

Materials and methods

The study population included 153 Portuguese Caucasians that were selected from a database of 504 retrospectively analysed computed tomography (CT) scans. A genetic test was performed, and a model was created through logistic analysis and regression coefficients. The statistical methodologies included were the independent Chi test, Fisher’s exact test, binary logistic regression and the receiver operating characteristic (ROC) curve.

Results

The estimated prevalence of IRAK4 gene polymorphism found in a Portuguese Caucasian population was 26.8 % (CI 95 %) [20.1, 34.7 %]. A model to predict the inflammatory response in the maxillary sinus in the presence etiological factors of dental origin was constructed. This model had the following as variables: previously diagnosed sinusitis, sinus pressure symptoms, cortical bone loss observed on CT, positive genetic test result and radiographic examination that revealed the roots of the teeth communication with the maxillary sinus, which are interpreted as risk factors.

Conclusions

The constructed model should be considered an initial clinical tool. The area under the ROC curve found, AUC = 0.91, revealed that the model correctly predicts the outcome in 91.1 % of cases.

Clinical relevance

The clinical relevance of this study lies in trying to achieve a potential tool (a model) that may assist the clinician in the implementation of suitable dental treatment plans in complex cases, with probable involvement of the maxillary sinus.

Prevalence of incidental maxillary sinus pathologies in dental patients on cone-beam computed tomographic images

OBJECTIVES

The aim of the present study was to infer and to record the prevalence of incidental maxillary sinus pathologies in patients presenting with dental problems using the cone-beam computed tomography (CBCT) scans performed for maxillofacial diagnostic purposes.

MATERIALS AND METHODS

This retrospective study has evaluated 201 patients (402 maxillary sinuses consecutive CBCT) for various incidental maxillary sinus pathologies by two observers. Pathologic findings were categorized as mucosal thickening (MT), opacification (OPA), polypoidal-mucosal thickening (PT), others (antrolith and discontinuity of the sinus floor) and no pathologic findings. Correlations for pathologic findings and the factors of age and gender were calculated.

RESULTS

The prevalence for total incidental findings is 59.7%. The present study showed MT (35.1%) as most prevalent finding followed by OPA in (16.6%), PT in 7.2% and others in 0.7%. There was no statistically significant difference between gender and between the age groups. There was no statistically significant difference between different indications groups for CBCT scans.

CONCLUSIONS

The incidental maxillary sinus abnormalities are highly prevalent in the asymptomatic dental patients; hence oral radiologists should be aware of these incidental findings and comprehensively evaluate the entire captured CBCT volume, which can help in early diagnosis, treatment and follow-up of the patient.

Sinus mucosal thickening in bisphosphonate-related osteonecrosis of the jaws: a case-control study

Osteonecrosis of the jaws is a clinically significant complication of bisphosphonate (BP) medications. Otherwise, the effects of BPs on oral soft tissue or cells remain unknown. The main objective of the present study was to determine whether the presence of sinus mucosal thickening was significantly related to BP-related osteonecrosis of the jaw (BRONJ). A case-control study was conducted on 32 patients who underwent treatment of BRONJ with conventional radiological investigations (panoramic radiographs) and computed tomography. The results indicated that patients with BRONJ had a 5.57-fold greater probability of presenting sinus mucosal thickening than controls. Although the existence of this thickening was more common in patients with advanced-stage disease or low levels of C-telopeptide-cross-linked type I collagen, no significant difference was observed between cases and controls. While considering the limitations inherent in the design and number of cases analyzed in our study, patients with osteonecrosis of the jaw were found to have a 5.57-fold greater probability of presenting sinus mucosal thickening (>3 mm) than healthy subjects.

The effects of sinus membrane pathology on bone augmentation and procedural outcome using minimal invasive antral membrane balloon elevation

Membrane pathology tends to complicate the postprocedural course of open sinus lift by ostio-meatal complex (OMC) obstruction and consequent acute sinusitis. The objective of this study was to evaluate the outcome of subjects with considerable sinus membrane pathology undergoing maxillary sinus floor augmentation and simultaneous implant placement using the minimal invasive antral membrane balloon elevation (MIAMBE) method. This study was a retrospective chart review of MIAMBE procedures performed in the presence of significant sinus membrane pathology. Sixteen patients with maxillary sinus membrane thickening in well-ventilated OMC as determined by dental computerized tomography underwent sinus augmentation and simultaneous implant placement using the MIAMBE technique. All 16 procedures were successfully concluded without significant procedural or postprocedural complications or implant failure. Post MIAMBE membrane pathology regressed or disappeared in 8 patients (50%) or remained unchanged in 6 patients (37.5%), while in 2 patients the sinus membrane pathology was limited to evaluation by periapical X rays. Sinus augmentation using the MIAMBE technique can be performed safely in asymptomatic patients in the presence of sinus membrane pathology if the OMC is not obstructed. In a significant proportion of these cases, complete resolution of the membrane pathology after MIAMBE is observed. When compared to open sinus lift, OMC obstruction is less likely to occur when employing the MIAMBE method.

Association between periapical lesions and maxillary sinus mucosal thickening: a retrospective cone-beam computed tomographic study

INTRODUCTION

Odontogenic infections are a common cause of maxillary sinusitis. This study aimed to evaluate the relationship between teeth with periapical lesions or periodontal disease and sinus mucosal thickening using cone-beam computed tomography (CBCT) imaging.

METHODS

CBCT scans of 243 patients (485 sinuses) were evaluated retrospectively for the presence of periapical lesions and/or periodontal disease in posterior maxillary teeth and associated sinus mucosal thickening. Thickening >2 mm was considered pathological and was categorized by degree (2-5 mm, 5-10 mm, and >10 mm) and type (flat or polypoid). Descriptive, bivariate, and multivariate statistical analyses were performed.

RESULTS

Mucosal thickening >2 mm was observed in 147 (60.5%) patients and 211 (44.6%) sinuses and was mostly of a "flat" type. Bivariate analysis revealed significant associations between mucosal thickening >2 mm and sex (males), age (>60 years), and teeth with periapical lesions and periodontal disease (P ≤ .027). Multivariate regression analysis identified only sex (males, odds ratio = 1.98, P = .004) and teeth with periapical lesions (odds ratio = 9.75, P < .001) to be associated with mucosal thickening >2 mm.

CONCLUSIONS

Sinus mucosal thickening is a common radiographic finding, which is more likely to be observed in males (2×) and in relation to teeth with periapical lesions (9.75×).

Cone-beam computed tomographic analysis of sinus membrane thickness, ostium patency, and residual ridge heights in the posterior maxilla: implications for sinus floor elevation

OBJECTIVE

To determine, using cone-beam computed tomography (CBCT), the residual ridge height (RRH), sinus floor membrane thickness (MT), and ostium patency (OP) in patients being evaluated for implant placement in the posterior maxilla.

MATERIALS AND METHODS

CBCT scans of 128 patients (199 sinuses) with ≥1 missing teeth in the posterior maxilla were examined. RRH and MT corresponding to each edentulous site were measured. MT >2 mm was considered pathological and categorized by degree of thickening (2-5, 5-10 mm, and >10 mm). Mucosal appearance was classified as "normal", "flat thickening", or "polypoid thickening", and OP was classified as "patent" or "obstructed". Descriptive and bivariate statistical analyses were performed.

RESULTS

MT >2 mm was observed in 60.6% patients and 53.6% sinuses. Flat and polypoid mucosal thickening had a prevalence of 38.1% and 15.5%, respectively. RRH ≤4 mm was observed in 46.9% and 48.9% of edentulous first and second molar sites, respectively. Ostium obstruction was observed in 13.1% sinuses and was associated with MT of 2-5 mm (6.7%), 5-10 mm (24%), and >10 mm (35.3%, P < 0.001). Polypoid mucosal lesions were more frequently associated with ostium obstruction than flat thickenings (26.7% vs. 17.6%, P < 0.001).

CONCLUSION

Thickened sinus membranes (>2 mm) and reduced residual ridge heights (≤4 mm) were highly prevalent in this sample of patients with missing posterior maxillary teeth. Membrane thickening >5 mm, especially of a polypoid type, is associated with an increased risk for ostium obstruction. In the presence of these findings, an ENT referral may be beneficial prior to implant-related sinus floor elevation.

Occurrence of maxillary sinus abnormalities detected by cone beam CT in asymptomatic patients

Background

Although cone beam computed tomography (CBCT) images of the maxillofacial region allow the inspection of the entire volume of the maxillary sinus (MS), identifying anatomic variations and abnormalities in the image volume, this is frequently neglected by oral radiologists when interpreting images of areas at a distance from the dentoalveolar region, such as the full anatomical aspect of the MS. The aim of this study was to investigate maxillary sinus abnormalities in asymptomatic patients by using CBCT.

Methods

1113 CBCT were evaluated by two examiners and identification of abnormalities, the presence of periapical lesions and proximity to the lower sinus wall were recorded. Data were analyzed using descriptive statistics, chi-square tests and Kappa statistics.

Results

Abnormalities were diagnosed in 68.2% of cases (kappa = 0.83). There was a significant difference between genders (p < 0.001) and there was no difference in age groups. Mucosal thickening was the most prevalent abnormality (66%), followed by retention cysts (10.1%) and opacification (7.8%). No association was observed between the proximity of periapical lesions and the presence and type of inflammatory abnormalities (p = 0.124).

Conclusions

Abnormalities in maxillary sinus emphasizes how important it is for the dentomaxillofacial radiologist to undertake an interpretation of the whole volume of CBCT images.

Distributions of calcitonin gene-related peptide and substance P in the human maxillary sinus of Japanese cadavers

BACKGROUND

Substance P (SP) and calcitonin gene-related peptide (CGRP) are released by the nociceptive sensory nerve and are involved in blood flow, pain and inflammation in the nasal mucosa. The purpose of this study was to assess the distribution of the SP and CGRP nerve fibres related to blood supply within human Schneiderian membrane of the maxillary sinus (MS).

MATERIAL AND METHODS

In this study, the MS from Japanese cadavers was examined by whole-mount immunohistochemistry. Human male cadavers (ranging in age from 80 to 90 years) were used in this study.

RESULTS

SP- and CGRP-positive fibres were found around large vessels of the medialis superior alveolar branches and also within the floor region of the MS. The floor region of the MS was composed of complex branches of these fibres.

CONCLUSION

Our results give useful information for surgical sinus floor elevation in this region of the MS. These anatomical features may assist in the execution of a successful surgical procedure.

Cone-beam computed tomographic evidence of the association between periodontal bone loss and mucosal thickening of the maxillary sinus

BACKGROUND

The aim of the present study is to determine the relationship between dental findings and mucosal abnormalities of the maxillary sinus among dental patients, using cone-beam computed tomography (CBCT).

METHODS

Two hundred fifty CBCT scans of dental patients were studied. Dental findings of the upper posterior teeth, including periodontal bone loss, periapical lesions, and root canal fillings, were assessed. The presence of mucosal thickening and mucosal cysts of the maxillary sinus was recorded. Logistic regression analysis was used to determine the influence of periodontal bone loss, periapical lesions, and root canal fillings on these sinus mucosal abnormalities.

RESULTS

Mucosal thickening was present in 42% of patients and in 29.2% of sinuses studied. Mucosal cysts were observed in 16.4% of patients and in 10% of sinuses studied. Both abnormalities were present more frequently among males than females. Severe periodontal bone loss was significantly associated with mucosal thickening (odds ratio: 3.02, P <0.001), whereas periapical lesions and root canal fillings were not. There was no association between dental findings and mucosal cysts.

CONCLUSIONS

Severe periodontal bone loss was significantly associated with mucosal thickening of the maxillary sinus. Sinuses with severe periodontal bone loss were three times more likely to have mucosal thickening. Mucosal cysts were not associated with any dental findings.