Evaluation of maxillary sinus anatomical variations and lesions: A retrospective analysis using cone beam computed tomography

Anatomy of Maxillary Sinus: Focus on Vascularization and Underwood Septa via 3D Imaging

The study of the maxillary sinus anatomy should consider the presence of two features of clinical importance. The arterial supply course and the presence of the so-called Underwood septa are two important factors to consider when planning surgical treatment to reduce the risk of surgical complications such as excessive bleeding and Schneiderian membrane perforations. This study aimed to investigate the above-mentioned anatomical structures to improve the management of eventual vascular and surgical complications in this area. This study included a total of 200 cone-beam computed topographies (CBCTs) divided into two groups of 100 CBCTs to evaluate the arterial supply (AAa) course through the lateral sinus wall and Underwood's septa, respectively. The main parameters considered on 3D imaging were the presence of the AAa in the antral wall, the length of the arterial pathway, the height of the maxillary bone crest, the branch sizes of the artery in the first group, and the position of the septa, the length of the septa, and their gender associations in the second group. The CBCT analysis showed the presence of the arterial supply through the bone wall in 100% of the examined patients, with an average size of 1.07 mm. With regard to the septa, 19% of patients presented variations, and no gender difference was found to be statistically significant. The findings add to the current understanding of the clinical structure of the maxillary sinus, equipping medical professionals with vital details for surgical preparation and prevention of possible complications.

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

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

Anatomical variations and abnormalities of the maxillary region and clinical implications: A systematic review and metaanalysis

OBJECTIVE

The objective of this review is to investigate and analyze the anatomical variations present in the maxillary sinus (MS), through the examination of the prevalence of these variations, as well as the corresponding prevalence of clinically significant pathologies and complications associated with them.

METHODS

The search process was carried out in the following databases; MEDLINE, SCIELO, WOS, CINHAL, SCOPUS, and GOOGLE SCHOLAR, using as search terms; "Maxillary bone," "Maxillary sinus," "Paranasal sinus," "Anatomical variations," "Sinusitis" and "Clinical anatomy."

RESULTS

A total of 26 articles and 12969 samples were included, from which 12,594 subjects had their sex recorded giving a total of 5802 males and 6792 females. The variants reported by the included were Haller cells, Concha Bullosa, Number of septa, Hypoplastic sinus, Agger Nasi, Thickening of the MS mucosa, Deviation of the nasal septum, Accessory ostium, and Onodi cells. Among the mentioned, the ones that presented the greatest number of studies (between 8 and 10 studies included) were: the Haller Cells, the Concha Bullosa, and the Number of septa, where prevalence was 0.30, 0.36, 0.39 respectively. These variations can lead to sinusitis, cause some types of tumors, or affect neighboring structures that could be compromised by this variation.

CONCLUSION

As a result, it is certainly complex to distinguish the presence of anatomical variations from pathological abnormalities. Therefore, knowledge of the different variations and their clinical relationships could be a useful asset for clinicians dedicated to this region.

Are maxillary sinus variations related to maxillary sinus diameters?

OBJECTIVES

The reasons why the maxillary posterior region is challenging for dentists are its structure and anatomical variations. For this reason, it is necessary to have complete knowledge about the anatomy of this region. In dentistry, necessary information for the desired evaluation in this region can be provided by CBCT. The fact that it provides a three-dimensional evaluation and has measurement reliability emphasizes its importance in surgical applications. The septa, haller cell, and accessory ostium are variations of the maxillary sinus. There are few studies in the literature examining the relationship between maxillary sinus diameters and its variations. The aims of this study are to determine the prevalence of maxillary sinus variations and the average of maxillary sinus diameters, to examine their relationships according to age and gender, and to evaluate the effects of maxillary sinus diameters on variations.

METHODS

In this retrospective study, CBCT images of 212 patients were examined. The examined CBCT images were analysed and recorded in more than one section. Descriptive statistics, chi-square tests, independent t test, one-way Anova tests were used to evaluate the data.

RESULTS

As a result, a statistically significant difference was observed between the variations, gender and age groups in terms of morphometric characteristics of the maxillary sinus. The most common variation was observed to be accessory ostium.

CONCLUSIONS

The rate of patients with at least one anatomical variation was 77.8%. For this reason, a detailed analysis should be performed to avoid complications before surgical procedures are performed in the area.

[Maxillary sinus lesions and their association with apical lesions observed by cone beam computed tomography. A retrospective cross-sectional study]

Introduction

Through cone beam computed tomography, alterations in the maxillary sinuses, such as opacities, space occupation and thickening of the mucosa, can be observed. Some factors contribute to this thickening, standing out among dental factors, periodontitis, apical pathology and endodontic treatments.

Objective

To evaluate the association between changes observed in the maxillary sinuses and apical lesions using cone beam computed tomography.

Materials and methods

It was a descriptive study with a retrospective and cross-sectional, correlational, field, non-experimental design. The sample consisted of 115 tomographic volumes obtained using Planmeca ProMax 3D Classic equipment (Planmeca, Helsinki, Finland). The presence/absence of endodontic treatment in the present posterior teeth, presence/absence of periapical lesion associated with these teeth, the size of the periapical lesion, presence/absence of alteration in the maxillary sinus and its thickness were evaluated.

Results

Apical lesions were observed that averaged a size of 3.32 ± 1.82 mm, and almost half (44.35%) presented between 2 and 4 mm in size. The main alteration of the maxillary sinus that was observed was the thickening of the mucosa (58.26%). The average thickness of the thickening of the sinus mucosa was 3.51 ± 1.78 mm, with 72.17% of the cases with thickening greater than 2 mm.

Conclusion

There was an association between the changes observed in the maxillary sinuses and apical lesions. The larger and closer the lesion was to the sinus, the greater the thickening of the sinus mucosa.

Diagnostic value of CBCT in Chinese children with adenoid hypertrophy

Objective

The main objectives of the study were to investigate the reliability and accuracy of cone‐beam computed tomography (CBCT) in the diagnosis of adenoid hypertrophy in Chinese children and to evaluate its value in clinical diagnosis.

Methods

From January 2019 to January 2020, 300 children with sleep snoring in Xinhua Hospital Affiliated to Medical College of Shanghai Jiaotong University were retrospectively studied. All patients underwent nasopharyngoscopy (NE) and CBCT scanning. The sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio of CBCT were determined according to the diagnostic criteria of NE, and the consistency between CBCT and NE was evaluated.

Results

The clinical study of 300 children patients found that compared with NE, CBCT had a sensitivity of 87.3%, specificity of 89.2%, the positive predictive value of 93.20%, the negative predictive value of 80.5%, the positive likelihood ratio of 8.08, the negative likelihood ratio of 0.14, and Kappa value of .748.

Conclusion

CBCT is a reliable and accurate tool for the diagnosis of adenoid hypertrophy and can be used as an alternative examination method for children with contraindications or intolerance during NE.

Level of Evidence

4.

Prevalence of and factors associated with maxillary sinus cyst in a Chinese population

PURPOSE

This study used cone-beam computed tomography (CBCT) to assess the prevalence of and factors associated with maxillary sinus cysts (MSCs) in a Chinese population.

METHODS

A total of 2,571 CBCT scans of 5,000 sinuses were analyzed. MSCs were diagnosed on the basis of imaging features within the maxillary sinus. Sex, age, dental condition, and anatomic condition were assessed. Associations with these factors were evaluated with logistic regression and a generalized estimating equations model.

RESULTS

The prevalence of MSCs was 15.46% at the sinus level and 23.44% at the patient level. The prevalence of MSCs was higher for men (OR = 1.864, P < 0.001) and for patients with apical lesions (OR = 1.76, P < 0.001), severe bone loss (OR = 1.363, P < 0.05), tooth roots in contact with the sinus floor (OR = 1.68, P < 0.001), and pits or septa on the floor of the maxillary sinus (OR = 1.539, P < 0.001).

CONCLUSION

This large sample had a high prevalence of MSCs. MSC prevalence was associated with multiple factors, including sex, dental condition, and anatomic condition. Maintenance of healthy dental and periodontal status might help prevent MSCs.

Prevalence of maxillary sinus septa: systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to determine the prevalence and characteristics of maxillary sinus septa using cone beam computed tomography and computed tomography data. Publications were searched until October 5, 2020 in three electronic databases. Additionally, article bibliographies were searched, and authors were contacted if required. This review has been registered in PROSPERO (CRD42019124933). Two independent evaluators assessed methodological quality using the Joanna Briggs Institute levels of evidence; inter-rater reliability tests were performed (Cohen's κ). The prevalence of maxillary sinus septa was expressed as a proportion; differences according to sex were reported in terms of the odds ratio (OR) and 95% confidence interval (95% CI). Heterogeneity and sources of heterogeneity were evaluated by meta-regression. Publication bias was assessed by visual analysis of the funnel plot. Statistical significance was set at P < 0.05. The 62 studies identified and included in the review involved 13,701 patients (22,460 sinuses). The meta-analysis of 35 studies (14,664 sinuses) revealed an overall mean sinus septa prevalence per sinus of 33.2% (95% CI 27.8-38.5%; I² = 98.32%). The meta-analysis of 42 studies (9631 patients) found an overall mean sinus septa prevalence per patient of 41.0% (95% CI 36.0-46.0%, I² = 96.45%). The OR for the difference in septa prevalence between sexes was 0.785 (95% CI 0.590-1.046; P = 0.098, I² = 73.24%). Septa were most frequent in the middle area of the sinus and with a transverse orientation (86.0%). Within the limitations, the results suggest a high proportion of septa in the sinus, commonly in the middle area, which can interfere with the success of sinus floor elevation required for implant rehabilitation.

[Automated system of the determination of maxillary sinus morphometric parameters]

THE AIM OF THE STUDY

Was to compare manual, semi-automatic and automatic methods for determining the maxillary sinus volume using cone beam computed tomography (CBCT).

MATERIAL AND METHODS

CBCT images from 48 patients (96 maxillary sinuses) with no history of sinus and alveolar bone surgery, who were presented to Minsk medical centers, were used in this study. Neural network training was performed on CBCT scans of 42 patients (84 maxillary sinuses).The height, depth and width of the sinus were measured manually on CBCT scans of 6 patients (12 maxillary sinuses). Maxillary sinus volume (V) was calculated by the formula: V=height´depth´1/3 width. Semi-automatic segmentation was carried out by an expert radiologist. The convolutional neural network technology was applied for maxillary sinus automatic segmentation.

RESULTS

The largest values were revealed by using the automatic method for sinus volume measurement. These values were within the 95% confidence interval (±4.29 cm³) of the average sinus volume obtained from semi-automatic method.

CONCLUSION

The data obtained using the convolutional neural network technique (artificial intelligence) has a high correlation with the results of sinus morphometric analysis acquired through manual and semi-automatic methods. Automatic maxillary sinus segmentation technique does not require special user knowledge. This method is reproducible and it is implemented in a short time interval.

Anatomical Variations of the Nasal Cavities and Paranasal Sinuses: A Systematic Review

The anatomy of the nasal cavities and paranasal sinuses is one of the most varied in the human body. The aim of this study is to review the prevalence of anatomical variations in the sinonasal area. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We performed on PubMed a literature search from October 2004 until May 2020. The search strategy included the following keywords: ('paranasal sinus' OR 'frontal sinus' OR 'maxillary sinus' AND ('anatomical variants' OR 'anomalies')). Fifty studies were eligible and included in the analysis. Overall, the studies encompassed a total of 18,118 patients included in this review. Most common anatomical variations include agger nasi cells, nasal septum deviation and concha bullosa. Other variations seen in this region are uncinate process variations, paradoxical middle turbinate, Haller, Onodi and supraorbital ethmoid cells, accessory ostia of maxillary sinus. Less common variations include any sinus aplasia, crista galli pneumatization and dehiscence of the optic or maxillary nerve, internal carotid artery and lamina papyracea. Anatomical variations of this region also differ among ethnic groups. This study highlights the amount, variability and significance of most anatomical variants reported in the literature in the last years. It is essential for the sinus surgeon to have a broad spectrum of knowledge not only of "the typical" anatomy but also all the possible anatomical variations. With modern imaging modalities, anatomical variations can be detected, and uneventful pitfalls might be prevented.

[Function and physiology of the maxillary sinus]

BACKGROUND

The question of the "true" function of the maxillary sinus and the paranasal sinuses (PS) has been a controversial issue in the literature for decades, leading to many discussions and speculations.

OBJECTIVE

This review briefly summarizes various theories on the possible physiology and functions of the maxillary sinus/PS that have been discussed over the centuries.

MATERIALS AND METHODS

A literature search was conducted in PubMed using a combination of the search terms "physiology," "function," "maxillary sinus," and "paranasal sinuses."

RESULTS

Current and scientifically evidenced theories are described. "Sinusology" is the science of the PS. The maxillary sinuses might simply serve to improve the respiratory function of the nose. A flow of inspiratory air does not occur. The maxillary sinuses are decisively involved in the production of nitrogen monoxide (NO) and thus in supporting the immune defense of the nasal cavity. The mucosa of the maxillary sinus continuously synthesizes NO and serves as a reservoir of NO. Other important functions are protection of the orbit and the brain in case of skull fractures, as well as weight reduction of the skull.

CONCLUSION

The various theories about the function of the PS still raise many questions and their true function is yet not fully understood. Possible functions of the maxillary sinuses are local immune defense through the production of NO. The PS serve as a crumple zone for vital cerebral structures in the context of craniocerebral traumas.