Correlations between anatomical variations of the nasal cavity and ethmoidal sinuses on cone-beam computed tomography scans

The Ethmomaxillary Sinus-A False Duplicate Maxillary Sinus

Functional endoscopic sinus surgery consistently benefits from good anatomical knowledge and modern imaging techniques. Ethmoid air cells migrate in specific topographical sites near the ethmoid. Posterior ethmoid air cells that descend into the maxillary sinus (MS) are ethmomaxillary sinuses (EMSs) that into the superior nasal meatus. Few previous studies found EMSs in 0.68% to 16.48% of cases. An EMS differs from a Haller's infraorbital cell nearing the ethmoidal infundibulum. A posterior ethmoid air cell intercalated between the ethmoid, MS and sphenoidal sinus is a Sieur's cell, but it could also be regarded as an EMS. An EMS should be discriminated from a maxillary recess of the sphenoidal sinus. An EMS could determine Onodi's maxillary bulla into the MS. The false duplicate MS described by Zuckerkandl consists of a MS draining into the middle nasal meatus adjoined by an EMS draining into the superior nasal meatus. These are separated by the ethmomaxillary septum. The latter may be confused with an intrasinus septum of the MS if the drainage pathways are not adequately documented. Therefore, a case-by-case anatomic identification of the pneumatic spaces nearing the MS should be performed before surgical endoscopic approaches of the nose and sinuses.

Does Frontal Recess Cell Variation Associate with the Development of Frontal Sinusitis? A Narrative Review

Chronic rhinosinusitis (CRS) can have a significant impact on quality of life. With persistent symptoms and the failure of initial medical treatments, surgical management is indicated. Despite the excellent results of endoscopic sinus surgery for persistent CRS, it is quite a challenging procedure for frontal sinusitis given the complex anatomy and location of the frontal sinus. Frontal recess cells significantly contribute to the complexity of the frontal sinus, and numerous studies have sought to establish their association with sinusitis. This review offers a comprehensive understanding of frontal recess cells, their different classifications, their prevalence among different populations, and their relationship to sinusitis. After an extensive review of the current literature, the International Frontal Sinus Anatomy Classification (IFAC) is the most recent classification method and a preferred practical preoperative assessment tool. Although the agger nasi cell is the most prevalent cell among all reported populations, ethnic variations are still influencing the other cells' distribution. Studies are inconsistent in reporting a relationship between frontal recess cells and sinusitis, and that is mainly because of the differences in the classification methods used. More research using a standardized classification method is needed to understand the association between frontal recess cells and sinusitis.

Combined Radiological and Endoscopic Evaluation of Sino Nasal Anatomical Variations in Patients of Chronic Rhinosinusitis: A North Indian Study

To determine the prevalence of anatomical variations of nasal cavity and paranasal sinuses of patients with chronic rhinosinusitis (CRS) on CT scan imaging. To correlate the Anatomical variations with the extent of CRS. 100 patients attending the ENT outpatient department with clinically diagnosed CRS were selected for study based on inclusion and exclusion criteria. Patients were subjected to CT scan and diagnostic nasal endoscopy. The correlation of anatomical variation with severity of CRS based on radiological score and endoscopic score was observed. Deviated nasal septum was the most common anatomical variation observed in 71% cases. Followed by Agger nasi (68%), concha bullosa (55%), Onodi cell (25%), Haller cell (14%), frontal sinus hypoplasia (2%) and uncinate bulla (1%) respectively. Statistically significant relationship of radiological score with left side Bullous Concha Bullosa and highly statistically significant relationship with Haller Cell was observed. While statistically significant relationship between Deviated Nasal Septum on left side with endoscopic score was also observed. Correlation of anatomical variation with CRS concludes on the note that some variations cause impaired sinus drainage and ventilation leading to recurrent sinusitis. Also, incidence of these variations was comparable to other studies done in asymptomatic population therefore, simply detection of a solitary anatomical variant itself does not determine predisposition to disease or the pathogenesis of the CRS and that we should have a critical look out for these anatomical variations from point of view of surgical management.

Variations of the Nasal Septum in Adult Nigerians: Computed Tomography Study

Introduction  The morphological variants of the nasal septum have been implicated in sinus pathology and pose a challenge during endoscopic surgeries. Objective  The present study aimed at evaluating the prevalence of nasal septum variants in adult Nigerians. Methods  The present study was performed at the Radiology Department of Delta State University Teaching Hospital, Nigeria, following ethical approval. Brain computed tomography (CT) scan images of 336 adults were evaluated for nasal septum variants. The angle of the deviated nasal septum was measured, and the severity was classified. Data were analyzed using IBM SPSS Statistics for Windows, version 23.0 (IBM Corp., Armonk, NY, USA). The angle of deviation was presented in means and standard deviation. Frequencies of the variants were presented in percentages. The Student t -test was used to compare the angle of deviation, while the chi-squared test was used to compare the frequencies in the different groups. A p-value < 0.05 was considered statistically significant. Results  The prevalence of straight and deviated nasal septum was 59.5% and 40.5%, respectively. Deviation was predominant in females (46%) and, more frequently, of moderate severity (75%). The angle of deviation was significantly larger in males (12.55 ± 2.99°) than in females (11.13 ± 2.41°; p  = 0.003). Nasal spur had a prevalence of 11.9%, and its coexistence with deviated nasal septum was observed in 5.06%. Septal pneumatization was seen in 10 patients (3%). Conclusion  Deviation of the nasal septum occurred more in females and toward the left; however, the angle of deviation was significantly higher in males. Nasal septal spur and pneumatization were the least prevalent variants.

Comparison of Diagnostic Quality of Multidetector Computed Tomography and Cone-Beam Computed Tomography in High and Low Resolution Modes for Assessment of the Nasal Cavity

Background

We aimed to compare the diagnostic quality of multidetector computed tomography (MDCT) and cone-beam computed tomography (CBCT) in high (HR) and low (LR) resolution modes for assessment of the nasal cavity and paranasal sinuses.

Methods

This in vitro study was conducted on 5 dry human skulls by using a CBCT and a MDCT scanner in HR and LR modes to assess their diagnostic quality for 21 anatomical landmarks of the nose. The quality of images was evaluated by two oral and maxillofacial radiologists and a dentist using a four-point Likert scale of (I) poor, (II) decreased, (III) good, and (IV) excellent. Data were analyzed by STATA at 95% confidence interval. The Chi-square test was applied to compare the quality of visualization of landmarks based on the type of scanner.

Results

The diagnostic quality of HR CBCT and CT for the majority of landmarks was higher than that of LR CBCT and CT (P<0.05). The diagnostic quality of HR CBCT for agger nasi cells (P=0.010), olfactory cleft (P=0.032), sphenoethmoidal recess (P=0.032), and nasolacrimal duct (P=0.014) and LR CBCT for the middle turbinate (P=0.046) and middle meatus (P=0.031) was significantly higher than that of MDCT.

Conclusion

The diagnostic quality of HR CBCT and CT for the majority of the landmarks in the nasal cavity and paranasal sinuses was higher than that of LR CBCT and CT. For the majority of landmarks, the diagnostic quality of CBCT and CT was the same; while for some landmarks, the diagnostic quality of HR and LR CBCT was higher than HR and LR CT. In general, CBCT has high efficacy for evaluation of the paranasal sinuses and the nasal cavity, and provides diagnostic information comparable to those provided by CT, but with a much lower radiation dose.

Investigation of the prevalence and main features of skull-base anomalies and characteristics of the sphenoid sinus using cone-beam computed tomography

Objectives

This study aimed to define the prevalence and characteristics of skull base anomalies and the features of sphenoid sinus pneumatization (SSP).

Materials and Methods

Five hundred cone-beam computed tomography scans were evaluated retrospectively for the presence of fossa navicularis magna (FNM), canalis basilaris medianus (CBM), sphenoid emissary foramen (SEF), and/or Onodi cells (OC). Patterns of the SSP and sphenoid sinus mucosa dimensions (SSMD) were also recorded.

Results

The prevalence of FNM, CBM, SEF, and OC was 26.0%, 22.4%, 47.4%, and 18.4%, respectively. Two hundred sixty-two (52.4%) sellar-type SSP were defined, followed by post-sellar 191 (38.2%), pre-sellar 31 (6.2%), and conchal 16 (3.2%) types. The frequency of SSMD less than 1 mm, 1-3 mm, and greater than 3 mm was 40.6%, 38.4%, and 21.0%, respectively. An SEF was detected more frequently in females, while SSMD greater than 3 mm was more frequent in males. An FNM was more prevalent in the 18-29 and 30-39 age groups and SEF was significantly less frequent in patients over 60 years of age compared to other age groups. A sinus mucosa larger than 3 mm was more common in the younger than 18 year group. The frequency of post-sellar-type pneumatization was lower in patients younger than 18 years.

Conclusion

Skull-base anomalies are common and may be detected incidentally during imaging procedures. The sphenoid sinus, its variations, and pneumatization patterns should also be taken into consideration in imaging procedures performed for various purposes.

Anatomical variations of the ethmoid sinuses and their association with health or pathology of the ethmoid and maxillary sinuses in a Southern Chinese population: An analysis using cone-beam computed tomography

Purpose

The aim of this study was to evaluate the prevalence of clinically relevant anatomical variations of the ethmoid sinuses and their potential association with ethmoid and maxillary sinus pathologies on cone-beam computed tomography (CBCT) scans. Additionally, potential associations with different sides and demographic factors, including age and sex, were evaluated.

Materials and Methods

In total, 273 CBCT scans with complete ethmoid and maxillary sinuses were analyzed to determine the prevalence of Agger nasi cell, supraorbital ethmoid cell, Haller cell, Onodi cell, and ethmomaxillary sinus. In addition, the health or pathology of the ethmoid and maxillary sinuses was also recorded to assess correlations with the aforementioned variations.

Results

The prevalence of Agger nasi cell was found to be the highest (95.6%) in this study, followed by Onodi cell (60.4%), Haller cell (29.3%), and supraorbital ethmoid cell (19.4%). Ethmomaxillary sinus was the least common finding (16.5%). Males and persons above 61 years of age had a significantly higher frequency of supraorbital ethmoid cell and Onodi cell, respectively. However, no significant relationships were noted between anatomical variations of the ethmoid sinus and pathologies of the ethmoid or maxillary sinus.

Conclusion

There was a high prevalence of ethmoid sinus variations in this Southern Chinese population. The prevalence of Agger nasi cell and Onodi cell was higher than that of other anatomical variations of the ethmoid sinuses. Anatomical variations of the ethmoid sinuses were not associated with ethmoid or maxillary sinus pathologies in this patient cohort.

A comprehensive morphometric analysis of crista galli for sex determination with a novel morphological classification on computed tomography images

PURPOSE

This study aimed to examine the morphometry of the crista galli (CG) on paranasal sinus computed tomography (PNCT) images to develop a new approach of morphological classification with objective radiological criteria and to investigate the relationship of morphometric and morphological characteristics with gender.

METHODS

The height, width, and length of the CG were measured on the PNCT images of 533 subjects (266 males, 267 females). Based on the dimensions and the presence of the cavitary component of the CG, the CG was classified into three morphological types. The success of CG dimensions and new morphological classification of CG in the determination of gender was evaluated with ROC and Paired Logistic Regression analyses.

RESULTS

The morphometric cutoff values of the height, width, and length of the CG for the estimation of gender were determined as 15.15, 3.45, and 13.25 mm, respectively. CG length (accuracy 83.7%) showed more successful classification rate on gender determination as compared to height (accuracy: 81.4%), and width (accuracy 81.2%) of the CG. The presence of ossified type CG accurately identified the male sex at a rate of 88.7%, and teardrop type CG determined female sex at a rate of 82.9%. Tubular type CG identified male sex correctly at the rate of 65.8%.

CONCLUSION

The height, length, and width measurements of CG on PNCT images and the new morphological types recommended in this study can be used in the determination of gender with high accuracy rates.

Characteristic features of fungus ball in the maxillary sinus and the location of intralesional calcifications on computed tomographic images: A report of 2 cases

This report presents 2 cases of sinus fungus ball and describes the characteristic radiographic features of fungus ball in the maxillary sinus. Two female patients, aged 62 and 40 years, sought consultations at a dental hospital for the treatment of dental implants and tooth pain, respectively. Panoramic radiography and small field-of-view (FOV) cone-beam computed tomography (CBCT) did not provide detailed information for the radiographic diagnosis of fungus ball due to the limited images of the maxillary sinus. Additional paranasal sinus computed tomographic images showed the characteristic features of fungus ball, such as heterogeneous opacification and intralesional calcification of the maxillary sinus. The calcified materials of the fungus balls were located in the middle and superior regions of the maxillary sinus. It is necessary to use large-FOV CBCT for the detection of calcified materials in the upper maxillary sinus to confirm the diagnosis of fungus ball.

Assessing the Clinical Value of Performing CT Scan before Rhinoplasty Surgery

Introduction

The endonasal mucosal or anatomic pathologies could lead to poor functional results and dissatisfaction after rhinoplasty. Although computed tomography (CT) scan has become an integral part of the diagnostic paradigm for patients with pathologies of the paranasal sinuses, the use of CT scan for preoperative evaluation of patients seeking rhinoplasty is up for debate. Our aim in this study was to compare the efficacy of CT scan in diagnosing nasal pathologies with other evaluating tools in patients undergoing rhinoplasty.

Design

In this randomized controlled trial study, 74 consecutive patients seeking cosmetic rhinoplasty referred to otorhinolaryngology clinic were randomly assigned into three groups based on the perioperative evaluation method: the CT group, the nasal endoscopy group, and the control group (anterior rhinoscopy only). Surgical planning was made according to perioperative findings, and the identified endonasal pathologies were corrected during the surgery. The functional and aesthetic outcomes of the rhinoplasty were assessed by Nasal Obstruction Symptom Evaluation (NOSE), Rhinoplasty Outcome Evaluation (ROE), and the Visual Analogue Scale (VAS) tools before surgery and at 12-month follow-up.

Results

All outcome measures improved significantly in either group toward one year after rhinoplasty (all with p value <0.05). Subjects in the CT group demonstrated greater improvement in the NOSE, VAS, and ROE compared to other two groups (NOSE: p value = 0.17; VAS: p value = 0.024; ROE: p value = 0.042).

Conclusions

According to our study, perioperative CT is associated with greater patients' satisfaction and quality of life after rhinoplasty compared to either nasal endoscopy or anterior rhinoscopy. A preoperative CT scan may improve the outcomes of rhinoplasty.

The systolic pulmonary artery pressure and the E/e' ratio decrease after septoplasty in patients with grade 2 and 3 pure nasal septal deviation

INTRODUCTION

Nasal septal deviation may contribute to a wide range of symptoms including nasal obstruction, headache, increased secretion, crusting, mucosal damage, and loss of taste and smell. Excessive increase in the respiratory resistance, as seen in nasal septal deviation, results in reduced lung ventilation, thereby potentially leading to hypoxia, hypercapnia, pulmonary vasoconstriction. The deformities in the nasal cavity can be associated with major respiratory and circulatory system diseases.

OBJECTIVE

To investigate cardiovascular effects of septoplasty by comparing pre- and postoperative transthoracic echocardiography findings in nasal septal deviation patients undergoing septoplasty.

METHODS

The prospective study included 35 patients with moderate and severe nasal septal deviation (mean age, 23.91±7.01) who underwent septoplasty. The Turkish version of the nasal obstruction symptom evaluation, NOSE questionnaire, was administered to each participant both pre- and postoperatively in order to assess their views on the severity of nasal septal deviation, the effect of nasal obstruction, and the effectiveness of surgical outcomes. A comprehensive transthoracic echocardiography examination was performed both preoperatively and at three months postoperatively for each patient and the findings were compared among patients.

RESULTS

Mean preoperative NOSE score was 17.34±1.62 and the mean postoperative score was 2.62±1.68 (p=0.00). Mean preoperative systolic pulmonary artery pressure value was 22.34±4.31mmHg and postoperative value was 18.90±3.77mmHg (p=0.00). Mean E/e' ratio was 5.33±1.00 preoperatively and was 5.01±0.90 postoperatively (p=0.01). The NOSE scores, systolic pulmonary artery pressure values, and the E/e' ratios decreased significantly after septoplasty (p<0.05 for all), whereas no significant difference was found in other transthoracic echocardiography parameters (p>0.05).

CONCLUSION

The decrease in NOSE scores following septoplasty indicated that the satisfaction levels of the patients were increased. Upper airway obstruction secondary to nasal septal deviation may be a cardiovascular risk factor and may affect transthoracic echocardiography measurements. Moreover, the significant decrease in the systolic pulmonary artery pressure value and E/e's ratio following septoplasty indicated that negative echocardiographic findings may be prevented by this surgery.

Efficiency evaluation of rapid maxillary expansion treatment on nasal septal deviation using tortuosity ratio from cone-beam computer tomography images

BACKGROUND AND OBJECTIVE

This study aims to assess the effect of Rapid Maxillary Expansion (RME) on Nasal Septal Deviation (NSD) changes from three-dimensional (3D) images.

METHODS

In this study, cone-beam computed tomography (CBCT) images from 15 patients with maxillary constriction (mean age 12 ± 1.6 years) were included. RME treatment with Hyrax appliance was performed in all patients. CBCT scans were taken at three different times; before appliance insertion (T0), after active expansion (T1) and 3 months after appliance insertion (T2). We developed a novel Matlab-based application to quantify NSD based on the tortuosity ratio by dividing the actual length of the septum by the ideal length in the mid-sagittal plane by using this application.

RESULTS

Tortuosity ratio (TR) values were found as 1.03 ± 0.03 (T0), 1.02 ± 0.02 (T1), and 1.02 ± 0.02 (T2). Differences of TR values among these groups were evaluated using the statistical method of ANOVA (ANalysis Of VAriance) for repeated measures with the significance level of p ≤ .05. Results showed significant reductions in TR values between T0-T1 (p ≤ .05) and between T0-T2 (p ≤ .05). Nonetheless, a significant difference between T1-T2 was not determined (p > .05).

CONCLUSIONS

As a result, we can conclude that the NSD degree is affected by the RME treatment. The developed application can be used for both educational and research purposes.

Nasal cavities and the nasal septum: Anatomical variants and assessment of features with computed tomography

The nasal cavities are complex anatomical structures with high inter-individual variability that relates to different functions. Different anatomic variants may manifest at this site, mainly belonging to the nasal septum and turbinates. Precise knowledge of the anatomy and variants is fundamental for both radiologists and ENT surgeons. This article provides an overview of the main anatomic variants and their frequency, according to the existing literature, as well as ongoing research on nasal cavity segmentation in order to obtain personal 3D models and to predict post-surgical results.