Anatomical variations in the human paranasal sinus region studied by CT

Investigation of nasal cavity alterations in individuals with neurofibromatosis type 1 using CBCT

OBJECTIVES

This study aimed to investigate nasal septum deviation (NSD), nasal bone length (NBL), and the morphology of the middle nasal conchae (MNC) and inferior nasal conchae (INC), as well as their correlations.

MATERIALS AND METHODS

The sample included 56 cone-beam computed tomography scans divided into two groups: a study group (SG; individuals with NF1; n = 28) and a control group (CG; individuals without NF1; n = 28). NSD, NBL, MNC, and INC classifications were assessed. MNC images were classified as normal, bullous, paradoxical, secondary, and accessory. INC images were classified as normal, lamellar, compact, combined, and bullous. Intra- and interobserver reliability were evaluated.

RESULTS

SG had a mean NSD of 11.6° (±4.5°) compared with 9.6° (±3.2°) for the CG, showing moderate deviations with no significant difference between groups. SG had a mean NBL of 22.4 mm (±3.4 mm) compared with 22.1 mm (±3.2 mm) for the CG, with a statistically significant difference. Both groups exhibited normal, bullosa, and accessory MNC classifications. SG INC were normal, lamellar, and combined, whereas CG INC were normal and lamellar. There was a weak correlation between NSD and NBL across groups.

CONCLUSION

Individuals with NF1 showed longer NBL. The weak correlation between NSD and NBL suggested multifactorial influences on these variations. These findings advance our understanding of craniofacial development in NF1 and highlight the need for further research into nasal cavity involvement in this complex genetic disorder.

Unravelling the Complex Relationship Between Frontal Sinus Pneumatization and Paranasal Sinus Anatomical Variants: Insights from CT Imaging

The aim of this study was to analyse the relationship between frontal sinus pneumatization and its effect on various variations of paranasal sinuses on paranasal sinus CT scan. A total number of 100 patients (51 males, 49 females) were included in this study. Patients were divided into three groups on the basis of their frontal sinus pneumatization extent on paranasal sinus CT as Type 1 pneumatization (aplasia and hypoplasia), Type 2 pneumatization (medium) and Type 3 pneumatization (hyperplasia). The prevalence of various variations like pneumatization of upper and middle turbinate, presence of agger nasi, Haller and Onodi cell, maxillary sinus hypoplasia, extent of sphenoid sinus pneumatization, pneumatization of anterior clinoid process, pterygoid process and greater wing of sphenoid sinus, dehiscence and protrusion of internal carotid artery and optic nerve types were ascertained and compared within each group. The prevalence of Onodi cell, anterior clinoid process and greater wing of sphenoid pneumatization and optic nerves type 3 and 4 were higher in Type 3 frontal sinus pneumatization group as compared with other groups. Excessive pneumatization of frontal sinus has various effects on paranasal sinus variations. Surgeons dealing with endoscopic sinus surgery, maxillofacial and skull base surgery must be vigilant of association between these variations preoperatively for avoiding complications.

The incidence of concha bullosa: a retrospective radiologic study

AIM

This study was conducted to discuss the incidence, directions, and types of concha bullosa using studies in the literature.

MATERIALS AND METHODS

The images of patients who presented to the ENT clinic with different ENT symptoms in the last 7 years and had paranasal sinus tomography were analyzed retrospectively.

RESULTS

The study consisted of a total of 3133 patients, including 1534 females (48.96%) and 1599 males (51.03%). The age range of the cases was between 12 and 85 years, and the mean age was 57.25 years. Middle concha bullosa was detected in 1402 (44.74%) of the cases. Of these cases, it was determined that 320 (22.82%) had right, 311 (22.18%) had left, and 771 (54.99%) had bilateral middle concha bullosa. Of middle types of concha bullosa, lamellar type concha bullosa was detected in 575 (41.01%) patients, bulbous type in 363 (25.89%), and extensive type in 464 (33.09%). Of the cases with lamellar type middle concha bullosa, it was found that 130 (22.60%) had right side, 105 (18.26%) had left side, and 340 (59.13%) had bilateral lamellar type middle concha bullosa. Of the cases that were determined to have bulbous type middle concha bullosa, 97 (26.72%) had right side, 99 (27.27%) had left side, and 167 (46.00%) had bilateral bulbous type middle concha bullosa. Of the cases that were determined to have extensive type middle concha bullosa, 93 (20.04%) had right side, 107 (23.06%) had left side, and 264 (56.89%) had bilateral extensive type middle concha bullosa. The incidence of superior concha bullosa was determined in 487 (15.54%) of 3133 cases. Of these, bilateral superior concha bullosa was detected in 332 (68.17%) cases and unilateral in 155 (31.82%) cases.

CONCLUSIONS

Our study has the largest case series among studies investigating the incidence of concha bullosa. The incidence of concha bullosa appears to be common in the community. Additional studies may be useful to determine whether its high incidence is associated with other sinus pathologies and the extent of its effect on other rhinological complaints.

Nasal septal anatomical variations among Saudi population and their possible coincidence with sinusitis: a computed tomography scan study

The nasal septum is a crucial supporting factor for the nasal cavity and may develop several anatomical variants including septal deviation, spur and pneumatization. These variants could be associated with a higher incidence of sinusitis due to structural and functional alterations. So, the aim of this study was to assess the prevalence of nasal septal deviation (NSD), nasal septal spur (NSS) and nasal septal pneumatization (NSP) among the Saudi adult population and their links with the incidence of sinusitis by using computed tomography (CT). A retrospective study was achieved over a twenty-two months period on 681 adult Saudi subjects (420 males and 261 females) aged 20 years or older, referred for coronal CT evaluation of the paranasal sinuses. NSD and NSS were significantly more prevalent in males than females (80.0% vs. 67.4% respectively for NSD, and 34.5% vs. 24.9% respectively for NSS), while there was no statistical difference in frequency of NSP regarding gender (P=0.670). The incidence of sinusitis was significantly higher in presence of NSD and/or NSS (P<0.001 for both). On the contrary, NSP was not associated with a significant increase in the prevalence of sinusitis (P=0.131). In conclusion, NSD and NSS are more prevalent in males than females among the Saudi population with no statistical difference between both genders regarding the presence of septal pneumatization. Furthermore, sinusitis is more prevalent with the occurrence of NSD and NSS, and not related to the incidence of NSP.

Surgical and Radiological Differences in Intersphenoid Sinus Septation and the Prevalence of Onodi Cells with the Endoscopic Endonasal Transsphenoidal Approach

Background and Objectives: Understanding the anatomical variation in the sphenoid sinus is important to fully expose the sellar floor and clivus. Materials and Methods: The Onodi cell and intersphenoid sinus septation based on preoperative paranasal sinus computed tomography (PNS CT) and the surgical records of 877 patients who underwent the endoscopic endonasal transsphenoidal approach (EETSA) were retrospectively reviewed. Results: An intersphenoid sinus septum (ISS) blocking the clivus was defined as a pseudoclivus. Complete and incomplete pseudoclivuses were found in 2.97% and 10.5% of patients, respectively. Intraoperative and PNS CT ISS findings differed in 17.1% of patients. Misconceptions regarding a ridge or vertical ISS and confusion between an incomplete pseudoclivus and a vertical ISS were common. Conclusions: Because intraoperative and PNS CT findings may differ, anatomical variation in the paraclival area should be evaluated carefully. A pseudoclivus mimicking the clivus is important to attain a fully exposed EETSA surgical view.

Racial, Ethnic, and Gender Variations in Sinonasal Anatomy

BACKGROUND

Complications during endoscopic sinus surgery often result from unfavorable anatomy. The prevalence rates of such anatomic findings vary tremendously in the literature, in part due to the small, homogenous populations previously studied.

OBJECTIVE

To characterize the prevalence of sinonasal anatomic variants among ethnic groups and genders seen at an academic medical center.

METHODS

This is a retrospective cross-sectional study of adult subjects who underwent CT imaging of the sinuses from January 2019 to November 2020 at a tertiary academic setting. CT scans were analyzed systematically by 3 trained study personnel for the presence of critical sinus anatomic variants that endoscopic sinus surgeons typically evaluate for preoperatively. Chi-squared tests and analyses of variance were conducted to detect differences in the prevalence of structural findings between genders and races/ethnicities.

RESULTS

A total of 489 subjects (57% female) were included: 44 Asian, 14 Black/African American, 101 Hispanic/Latino, 203 White, 127 Other. The prevalence of the following anatomical variants differed by race/ethnicity: Haller cells, Type 3 optic nerve, Onodi cells, maxillary septations, sphenoid lateral recess, anterior clinoid process pneumatization, and carotid artery dehiscence. Asian subjects had higher rates of Haller cells (48% vs 16%, P < .001) and Type 3 optic nerve (18% vs 4%, P = .022) compared to Hispanic subjects, as well as a higher prevalence of Onodi cells (39% vs 17%, P = .003) compared to White subjects. Males had a higher prevalence of mesenteric anterior ethmoid arteries (62% vs 45%, P < .001) and dehiscent carotid arteries (30% vs 21%, P = .024).

CONCLUSION

Certain sinonasal anatomic variants, which have direct implications for complications during endoscopic sinus surgery, were found to be significantly more prevalent in some demographic groups. Surgeons should be aware of these differences in their review of preoperative imaging for safe surgical planning.

Prevalence of the anatomical variations of concha bullosa and its relation with sinusitis among Saudi population: a computed tomography scan study

Concha bullosa (CB) is a pneumatic cavitation inside a concha in the nasal cavity. It is one of the most widely recognized nasal variations and is mostly found in the middle concha. CB is divided according to its site into three types; lamellar, bulbous and extensive. The goal of our study was to estimate the prevalence of CB among Saudi adult population and its association with sinusitis by using multidetector computed tomography (MDCT). This was a retrospective study carried out over a three-year period on 879 adult Saudi patients aged 18 years or older, referred for MDCT assessment of paranasal sinuses. Males were 540 and females were 339. Patients with facial congenital anomalies or nasal trauma were excluded from our study. CB was prevalent in both males and females among Saudi population (55.4%, 55.7%) respectively. Bilateral CB (55.5%) was more frequent than unilateral (44.5%). Extensive CB (44.0%) was the most frequent type. Sinusitis was associated more in patients with CB (48.0%) versus those who have no CB (5.9%). In conclusion, CB was prevalent among Saudi population and the most frequently recorded is the extensive type. Furthermore, the most common type associated with sinusitis was extensive CB (49.6%).

Radiological middle turbinate variations and their relation to nasal septum deviation in asymptomatic adult

Background

Middle turbinate (MT) is one of the important anatomical and physiological structures of the nasal cavity. After the widespread use of nasal endoscope and paranasal sinus computed tomography (CT), many MT variations have been described. This study aimed to determine the incidence of MT variations by computed tomography (CT) in asymptomatic adult, their relation to each other, and to deviated septum (DS).

Results

In the included 86 subjects (172 MTs), pneumatized MT was the most common MT variation followed by paradoxical MT (PMT). Septal deviation did not appear to affect occurrence of pneumatized or PMT. Fifty-nine percent of the reported bilateral PMT were associated with pneumatized MT, while 35.7% of unilateral PMT were associated with pneumatized MT with non-significant difference.

Conclusion

MT variations in adults are common mainly pneumatized MT then PMT with no apparent relation to septum deviation.

Anatomographic Variants of Sphenoid Sinus in Ethiopian Population

Neurosurgeons often neglect the sphenoid sinus due to its deep location and difficulties in accessing during surgical interventions. Disease of the sphenoid sinus is difficult to diagnose since its presenting symptoms are difficult to recognize. Moreover, compared with other paranasal sinuses, the sphenoid sinus is considered the most variable air sinus in terms of its degree of pneumatization, number and position of inter-sinus septa, and its relationship with the surrounding anatomical structures. Anatomical variations of the sphenoid sinus are significant from a neurosurgical point of view. Understanding of these variations and its relationships with surrounding structures such as the internal carotid artery, optic nerve, and pituitary gland are clinically relevant to minimize injuries associated with surgical procedures that involve sphenoid sinus. We implemented principles of imaging using computed tomography to elucidate any anatomical variations of the sphenoid sinus in the Ethiopian population. We conducted a prospective study in 200 patients with ages 18-79, who underwent scans of the sphenoid sinus at the Tikur Anbessa Referral Teaching Hospital in 2017-2018. Our findings revealed an incidence of anatomographical variations in terms of pneumatization that varied between 2-50%. These variants include 2% conchal, 25.5% presellar, 50% sellar, and 22.5% postsellar pneumatization. We also demonstrated anatomographic variants in terms of septation, 77.5% single complete septa, 11.5% single incomplete, 10% double septa, and 1% absence of septa. In summary, the sellar pneumatization was found to be the most clinically relevant anatomographic variant among Ethiopians participating in the study, of which 90% were tomographically single septated. These variants must be taken into consideration during trans-sphenoidal surgery and knowledge of the variations has clinical implication in minimizing injuries during invasive surgical procedures involving the sphenoid sinus.

Anatomic variations of the osteomeatal complex and its relationship to patency of the maxillary ostium: A retrospective evaluation of cone-beam computed tomography and its implications for sinus augmentation

Aim:

The aim of this study is to determine the incidence of obliterated osteomeatal complex (OMC) due to the presence of anatomic variants.

Settings and Design:

Retrospective Study.

Materials and Methods:

In this retrospective study, a total of 71 patients, 34 males and 37 females, aged 35–65 years were included in the study. Cone beam computed tomography (CBCT) scans of patients were assessed to identify the status of the OMC in the presence of anatomic variants and their incidence was recorded. The radiological assessment of the anatomical variants was made by viewing the coronal sections of the scans. The variants observed were deviated nasal septum, uncinate process), agger nasi, Haller cells, middle turbinate variants, enlarged bulla, accessory ostium, and maxillary sinus abnormalities). Ostium patency was evaluated in the coronal section of each sinus and classified as “patent” or “obstructed.” The most common variants observed were then correlated with the patency of the ostium.

Statistical Analysis Used:

Chi square test was performed to assess the association between the anatomic variants and the patency of the OMC.

Results:

In the present study, the incidence of an obliterated OMC due to the presence of anatomic variants was 73.2%. The four most common variants associated with the possibility of an obliterated OMC were the deviated nasal septum (76.2%), middle turbinate (86.4%), enlarged bulla (77.8%), and sinus cavity variants (80.0%). A statistically significant association was noted between middle turbinate variants and Haller cells and the patency of the OMC.

Conclusion:

Thorough pretreatment CBCT evaluation should be performed to assess the presence of anatomic variants and thereby, the patency of the ostium before sinus floor elevation procedures. The pre and postsurgical treatment plans and regimes can be modified according to anticipated postsurgical sequelae, thereby avoiding postsurgical complications and enhancing the success of the graft procedure.

Modified Posterior Pedicle Middle Turbinate Flap: An Additional Option for Skull Base Resurfacing

OBJECTIVES/HYPOTHESIS

Although the Hadad-Bassagusteguy flap represents the first choice for middle and posterior skull base reconstruction and coverage of exposed bony areas, in some cases it is unavailable. The aim of this study is to describe, as an alternative option in selected cases, a modified posterior pedicle middle turbinate flap (mPPMTF) extended to the lacrimal area. Anatomical features, step-by-step harvesting technique, and surgical applications are presented.

STUDY DESIGN

Anatomic dissection study and case report.

METHODS

Four mPPMTFs were raised in two fresh-frozen cadaver heads. A study of the vascular supply and measurements of length, width, and area of the flap were performed. The ability of the flap to cover the ventral skull base, particularly the upper clivus area, was tested. A clinical case in which an mPPMTF was used for clivus resurfacing after osteoradionecrosis is reported.

RESULTS

The vascular supply of the mPPMTF was identified as the middle turbinate branch of the sphenopalatine artery. The flap had a mean length of 6.92 cm, mean maximum width of 1.08 cm, and mean total area of 5.33 cm² . The flap was able to reach the upper clivus, with a clival coverage ratio of 70.66%. In the clinical case, good surgical outcomes were observed, with accelerated re-epithelization without complications.

CONCLUSIONS

The mPPMTF represents an alternative to the Hadad-Bassagusteguy flap for posterior cranial fossa and nasopharynx resurfacing. The main drawbacks are its technically demanding and time-consuming harvesting.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E767-E774, 2021.

Imaging Analysis of Onodi Cells on Cone-Beam Computed Tomography

Introduction  Onodi cells are the most posterior ethmoid air cells, and extend superolaterally to the sphenoid sinus. The identification of Onodi cells is essential to because they can have some significant anatomic variations and relationships to vital adjacent structures, like the optic canal, the sphenoid sinus, and the internal carotid artery. Objective  The present study aimed to assess the prevalence of Onodi cells and their position with respect to sphenoid sinus. To the authors' best knowledge, this is the first study that uses cone-beam computed tomography (CBCT) to assess the prevalence and position of Onodi cells. Methods  We collected CBCT scan records from November 1st, 2016, to July 31st, 2017; the patients who fulfilled the eligibility criteria were included in the present study. The CBCT scans were reviewed by two independent observers. The descriptive statistics was performed using the Statistical Package for the Social Sciences (SPSS, SPSS, Inc., Chicago IL, US) software, version 17.0. A cross-tabulation of gender with the presence and position of Onodi cells was evaluated using the Chi-squared (χ ² ) test. The inter- and intraobserver agreements were evaluated using Kappa (κ) statistics. Results  Onodi cells were identified in 86 (42.8%) out of 201 patients. A subgroup analysis revealed that Onodi cells were present in 45 (43.3%) female and 41 (42.3%) male patients. The position of the Onodi cells was superior with respect to the sphenoid sinus in 43 (50%) of the patients, superolateral in 36 (41.9%), and lateral to the sphenoid sinus in 7 (8.1%) of the patients. Conclusion  The present study indicated a high prevalence of Onodi cells, with approximately equal distribution among males and females, and mostly superior in position in relation to the sphenoid sinus.

Computed Tomographic Study of Remarkable Anatomic Variations in Paranasal Sinus Region and their Clinical Importance - A Retrospective Study

INTRODUCTION

With the advent of functional endoscopic sinus surgery and coronal computed tomography (CT) imaging, more attention has been paid toward paranasal region anatomy. Detailed knowledge of anatomic variations in paranasal sinus region is critical for surgeons performing endoscopic sinus surgery as well as for the radiologist involved in the pre- and post-operative assessment. The anatomical variants with some accompanying pathologies would directly influence the success of diagnostic and therapeutic management of paranasal sinus diseases. Our study intends to explore the anatomy of paranasal air sinus through CT and to describe its variants, which may predispose to chronic sinusitis and complications in endoscopic sinonasal surgery.

MATERIALS AND METHODS

This was a retrospective study carried out in a tertiary institution. Two hundred and fifty patients without paranasal sinus symptoms who presented for head CT studies and gave consent for a coronal section scan of the paranasal sinuses to be taken in addition to the axial section of the head were included in the study. The CT examination was performed with GE Hispeed-NX/I Base-2002 Dual Slice Helical CT machine.

RESULTS

Among 250 study population, 100 were females and 150 males. Among these 423 cases of anatomical variants were observed. The most common anatomical variants were pneumatization of the middle nasal turbinates 30.73%. This is followed by agger nasi cells 21.64%, Haller's cells 22.91%, septal deviation 21.91%, and sphenoid sinus septation (20.18%).

DISCUSSION

CT is the gold standard in the radiologic investigation of the paranasal sinuses, sinonasal lesions, and inflammatory disease or pre- and post-surgical assessment. It has the capability of disclosing in greatest detail any anatomical variations, which could be causing or precipitating the sinusitis.

Intraoperative Sphenoid Sinus Volume Measurement as an Alternative Technique to Intraoperative Computer Tomography

Isolated sphenoid sinus disease (ISSD) is where there is a group of pathologies characterized by inflammation in one or both sphenoid sinuses. Although computer tomography (CT)-based 3D reconstruction remains the gold standard among noninvasive approaches to ISSD diagnostics, no standardized techniques for direct intraoperative measurements of the sphenoid sinus volume in ISSD patients have been documented. We suggest a novel technique for the intraoperative measurement of the sphenoid sinus volume. Our technique is based on filling the sinus with 0.01% methylene blue solution after an endoscopic endonasal sphenoidotomy. The proposed technique was applied to 40 ISSD patients during surgery. Obtained intraoperative measurements were compared to noninvasive measurements from 3D reconstructions based on preoperative CT scans. Our results demonstrated that the obtained measurements did not exhibit significant differences exceeding 0.4 cm³, with CT-scan-based measurements in 39 out of 40 cases (p < 10⁻⁶, Wilcoxon sign-rank nonparametric test), thus confirming the accuracy of the proposed technique. Disagreements between direct intraoperative and CT-based measurements in a single case have been attributed to the presence of remaining pathological masses in the sinus, which was further confirmed during the secondary check of the operated sinus. Accordingly, we suggest that the agreement between the CT-based and intraoperative volume measurements can be used as an indicator of the successful elimination of all pathological masses from the sinus without having to perform an adequate exposure of the entire sphenoid sinus to reduce intraoperative bleeding. The proposed technique is accurate and does not require the involvement of specialized intraoperative CT scanners and avoids additional radiation exposure for the patient during an additional postoperation CT scan to confirm the success of the surgery.

Sphenoid sinuses: pneumatisation and anatomical variants-what the radiologist needs to know and report to avoid intraoperative complications

PURPOSE

Sphenoid sinuses are pneumatised structures, placed in the body of the sphenoid bone, with highly variable morphology. The strict relationships with vascular and nervous structures determine the importance of their anatomical variants in otorhinolaryngology and neurosurgery; a precise understanding of the complex anatomy and anatomic variations of these structures is pivotal for radiological diagnosis of paranasal sinuses pathology and for surgical planning, to avoid potential complications. Our aim is to describe the anatomical variants of sphenoid sinuses, and to help general radiologists and specialists in endoscopic surgery in becoming familiar with these sensitive anatomical structures.

METHODS

A literature search of PubMed and Embase (Elsevier) databases was performed using the keywords "sphenoid sinus" and "anatomy, "sphenoid sinus" and "anatomic variants", "sphenoid sinus", and "anatomic variations".

RESULTS

We described the anatomical variants of the sphenoid sinuses anatomy, according to their size, shape, degree of pneumatisation, protrusion of anatomical structures into their lumen, superimposition of ethmoid cells (Onodi cells), and presence of accessory septations CONCLUSION: The information provided by this study may help in the identification and description of the anatomical variations of the sphenoid sinuses and their relationship to neurovascular structures.

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.

An additional challenge for head and neck radiologists: anatomic variants posing a surgical risk - a pictorial review

Anatomic variants in the head and neck are quite numerous and occur frequently: a minority of them increase the risk of complications during surgical procedures and may be visualized on cross-sectional images. As some of these complications are potentially fatal, awareness (and accurate reporting) of such variants is a basic responsibility of radiologists, particularly when surgery in the pertinent anatomic area is under consideration.

Total and Unilateral Peak Nasal Inspiratory Flow and Unilateral Visual Analogue Scale: Rationale in Indication and Outcomes of Septoplasty?

Septoplasty is one of the most frequently performed procedures in otorhinolaryngology. Proper selection of patients for septoplasty as well as examination is essential for good outcome of surgery. The aim of this study was to evaluate the suitability of combination of 2 simple, cheap, and easily performed examinations for indication and outcomes of septoplasty to evaluate the effectiveness in this type of surgery. Seventy patients were enrolled from 2 tertiary centers from the period of April 2017 to March 2018, who all underwent septoplasty for nasal septal deviation. Total and unilateral peak nasal inspiratory flow (PNIF), unilateral visual analogue scale, and nasal endoscopy for indication and outcomes of septoplasty were performed. Furthermore, assessment of possible correlation between subjective and objective data before and 3 months after septoplasty was done. Statistical analysis was carried out on the obtained data. Postoperatively the total and both unilateral PNIF measurements increased significantly compared with corresponding preoperative values and similarly means of visual analogue scale scores on both sides decreased 3 months after the procedure. No significant correlation was seen between objective and subjective outcomes neither before the surgery, nor postoperatively. The study confirmed the suitability of using PNIF as a simple and inexpensive tool that can be a reasonable alternative to rhinomanometry and which is able to reflect changes after septoplasty. Simultaneously, along with the expected improvement in the total PNIF and unilateral PNIF on deviated side, a slight but significant improvement in PNIF values on the nondeviated side was also demonstrated.

Ethnic Variation of Sinonasal Anatomy on CT Scan and Volumetric Analysis

To determine Ethnic differences in the frequency of the relatively common anatomical variants along with difference in anatomy of sinonasal region with surgical importance. A study was conducted to determine the frequency of anatomical variants, volumes of paranasal sinuses using computed tomography and to identify any difference between Group A consisting of people of Indian subcontinent and Group B consisting of people from north east Asian region. Volumetric analysis done using cumulative of area multiplied by slice thickness. The results were compared using Chi square test, p value < 0.05 was considered statistically significant. Among the common and uncommon anatomical variants (Agger nasi, pneumatized uncinate, concha bullosa etc.) there was no significant difference between the two groups. In both the groups Keros Type 1 was the most common type of ethmoid roof seen. On volumetric analysis sphenoid sinus volume was found to be higher in Indians without mongoloid features. Hence it's ideal that in this era of endoscopic sinus surgery we tailor make approaches to address individual anatomical variation.

Relationship between sphenoid sinus volume and accessory septations: A 3D assessment of risky anatomical variants for endoscopic surgery

Sphenoid sinus accessory septations involve serious complications during their removal for the injury of the internal carotid artery (ICA) and the optic nerve (ON). The relationships of this anatomical variant with sphenoid size still remain unclear. In the present study, 260 patients (equally divided among sexes, aged between 18 and 92 years) were retrospectively assessed. Number of accessory septations and their relationship with ICA and ON were recorded. The 3D model of sphenoid sinuses was extracted. Pearson's coefficient was calculated to assess correlations between the volume of sphenoid sinuses and the number of septations (P < 0.05). Sex-related differences in prevalence of septations inserted onto ICA or ON were assessed through chi-square test (P < 0.05). Differences in volume between patients with and without ICA or ON septal insertions were assessed through Mann-Whitney test (P < 0.05). In most of the cases, two septations were found (24.6%), whereas only 21.9% of patients did not show any septum. ICA and ON septal insertions were found in 20.8% and 7.7% of cases, respectively. Number of septations significantly increased with sinus volume, independently from sex (P < 0.001). Moreover, volume was significantly higher in patients with ICA septal insertion (P < 0.001), whereas no difference was found between subjects with and without ON septal insertion (P > 0.05). The present study first proved that septations and probability of ICA insertion are related with sphenoid volume. On the other side, ON insertion does not depend upon sphenoid sinuses size. Anat Rec, 303:1300-1304, 2020. © 2019 American Association for Anatomy.

Agger Nasi Cells Versus Lacrimal Cells and Uncinate Bullae in Cone-Beam Computed Tomography

The maxillary bone's frontal process, lacrimal bone, and ethmoidal labyrinth's uncinate process can each harbor pneumatizations, referred to as agger nasi cells (ANCs), lacrimal cells (LCs), and uncinate bullae (UBs), respectively. Different studies have failed to differentiate ANCs from LCs. We aimed at studying these 3 anatomic sites to establish the anatomical patterns that could be encountered. We performed a retrospective study on cone-beam computed tomography scans of 36 patients (72 sides); the anatomic identification was supported by bidimensional multiplanar reconstructions (MPRs) in all 3 planes and 3-dimensional volume renderings. We established 6 patterns of pneumatization as follows: (1) type I: single LCs (47%), (2) type II: distinctive adjacent LCs and ANCs (8%), (3) type III: LCs expanded as UBs (6%), (4) type IV: ANCs adjacent to LCs expanded with UBs (1%), (5) type V: ANCs expanded as LCs (27%), and (6) type VI: ANCs expanded as LCs and further expanded as UBs (11%). In a type I pattern case, we found a cell-in-cell aspect on sagittal MPRs, which was further demonstrated as being an anterolateral recess of the middle nasal meatus projected in front of an LC. Such an "agger nasi recess" of the middle meatus was not previously described. For an accurate anatomical diagnosis, computed tomography studies should use complementary MPRs in all anatomical planes, as well as 3-dimensional models, to avoid confusing ANCs with LCs and better document the drainage pathways.

Surgical anatomy of the nasal and paranasal sinuses in Egyptian native sheep (Ovis aries) using computed tomography and cross sectioning

The present work aimed to describe the normal computed tomography (CT) and cross-sectional anatomy of the nasal and paranasal sinuses in sheep and to correlate these features with the relevant clinical practices. Twenty apparent healthy heads of Egyptian native breed of sheep (Baladi sheep) of both sexes were used for studying these sinuses. CT images and their closely identical cross sections of the same head were selected and serially labelled in a progression from the rostral nasal region to the caudal aspect of the head using cheek teeth as landmarks. The current investigation reported seven sinuses in sheep, including maxillary, frontal, lacrimal and sphenoidal as paranasal, as well as dorsal and middle conchal and ethmoidal as nasal with unnoticeable palatine and ventral nasal conchal sinuses. The boundaries, extension, structure and communications of these sinuses were fully described. The current study provided anatomical guidelines for surgical interference in the frontal and maxillary sinuses during trephination, dehorning and sinuscopy. Also, an acceptable anatomical explanation was reported in this study for the high incidence of maxillary sinusitis than other sinuses. CT and cross-sectional anatomy could be used as helpful database for diagnosis and clinical interference of the nasal and paranasal sinuses in sheep.

Volumetric assessment of sphenoid sinuses through segmentation on CT scan

PURPOSE

Computed tomography represents the gold standard for the assessment of morphological characteristics of sphenoid sinuses, whose anatomy has acquired a novel interest because of the recent introduction of transsphenoidal surgery and robot-assisted procedures. One of the most relevant parameters for planning surgical intervention is the volume of sphenoid sinuses, and with time few population studies have been published. However, at present, no data are available concerning the relation between volume and anatomical variants of sphenoid sinuses.

METHODS

We retrospectively evaluated head CT-scans of 100 patients (age range 25-99 years; mean age males 45.0; mean age females 50.5 years) to calculate the volume of sphenoid sinuses through automatic segmentation. Possible statistically significant differences according to sex and variants of pneumatization, and type of sinus were assessed, respectively, through Student's t test and one-way ANOVA test (p < 0.05).

RESULTS

Average volume of sphenoid sinuses in males was 10.005 ± 5.101 cm³, in females 7.920 ± 3.176 cm³. Differences according to sex were statistically significant (p < 0.05). Patients with pneumatization of pterygoid processes, dorsum sellae and anterior clinoid processes had a significantly higher volume than unaffected subjects. Moreover, differences of volume according to the type of sphenoid sinus were statistically significant (p < 0.05).

CONCLUSIONS

Results show that volume of sphenoid sinuses strongly depend upon the type of sinus and possible pneumatization variants. Moreover, the important of ethnic variability is confirmed.

Sphenoethmoid Cell: The Battle for Places Inside of the Nose Between a Posterior Ethmoid Cell and Sphenoid Sinus: 3D-Volumetric Quantification

Background

Sphenoethmoid cells may be above the sphenoid sinus with/ or without con-tact to optical nerve. Although sphenoethmoid cells are theoretically considered to possibly influence the sphenoid sinus volume, we could not find any study in the literature on this issue.

Aims

The aim of our study was to detect sphenoethmoid cells and measure the sphenoid sinus vol-ume using multiplanar computerized tomography and also investigate the correlation between the presence of sphenoethmoid cells and the sphenoid sinus volume.

Methods

Retrospectively 141 patients who had available paranasal computerized tomography images were included in this study. The sphenoid sinus volumes of each patient were calculated individually for each side, and the relationship between the presence of sphenoethmoid cell and sphenoid sinus volume was investigated.

Results

Sphenoethmoid cells were detected at 106 (37.5%) of the total 282 sides in 141 patients. No gender difference was observed. The total sphenoid sinus volume was significantly lower in the group of patients who had bilateral sphenoethmoid cells than in the sphenoethmoid cell negative group. In patients with a unilateral sphenoethmoid cell, a significant decrease in the sphenoid sinus volume was observed only for the side where the sphenoethmoid cell was located.

Conclusion

It was observed that the sphenoethmoid cells caused a significant reduction in the sphe-noid sinus volume on the side where they were located. In the case of low sphenoid sinus aeration, the sphenoethmoid cell should be kept in mind. Further studies with an extended patient series are required to explore this issue.

Radiological sinonasal anatomy. Exploring the Saudi population

OBJECTIVES

To assess the prevalence of common radiological variants of sinonasal anatomy among Saudi population and compare it with the reported prevalence of these variants in other ethnic and population groups. 

METHODS

This is a retrospective cross-sectional study of 121 computerized tomography scans of the nose and paranasal sinuses of patients presented with sinonasal symptoms to the Department of Otorhinolarngology, King Fahad Hospital of the University, Khobar, Saudi Arabia, between January 2014 and May 2014. 

RESULTS

Scans of 121 patients fulfilled inclusion criteria were reviewed. Concha bullosa was found in 55.4%, Haller cell in 39.7%, and Onodi cell  in 28.9%. Dehiscence of the internal carotid artery was found in 1.65%. Type-1 and type-2 optic nerve were the prevalent types. Type-II Keros classification of the depth of olfactory fossa was the most common among the sample (52.9%). Frontal cells were found in 79.3%; type I was the most common.  

CONCLUSIONS

There is a difference in the prevalence of some radiological variants of the sinonasal anatomy between Saudi population and other study groups. Surgeon must pay special attention in the preoperative assessment of patients with sinonasal pathology to avoid undesirable complications.

Frequency and volumetry of infraorbital ethmoid cells (Haller cells) on cone-beam computed tomograms (CBCT) of the mid-face

Objective: The aim of this study was to determine the frequency and morphology of Haller cells using a new radiological technique that allows examination of the facial skull.

Material and methods: In a single center retrospective cohort study the cone-beam computed tomography (CBCT) volume data of the maxillary sinus of 199 patients were analysed (398 paranasal sinuses). If Haller cells were found, their capacity was determined. If orthopantomograms (OPG) were taken in a narrow time frame around the CBCT investigation, the rate of correspondence of the radiological findings was determined. The correlation between frequency of Haller cells and age and gender was calculated.

Results: Out of 199 patients 47 showed at least one Haller cell (23.62%). The total number of Haller cells was 64. Correspondence was rare in the same case between the results from different examination procedures with respect to the target object.

Conclusions: Bony variants of paranasal sinuses can be analysed using CBCT as an alternative to computed tomography (CT), whereas OPG images do not reliably detect Haller cells.

Cone-beam computed tomography analysis of accessory maxillary ostium and Haller cells: Prevalence and clinical significance

Purpose

This study aimed to evaluate the prevalence of Haller cells and accessory maxillary ostium (AMO) in cone-beam computed tomography (CBCT) images, and to analyze the relationships among Haller cells, AMO, and maxillary sinusitis.

Materials and Methods

Volumetric CBCT scans from 201 patients were retrieved from our institution's Digital Imaging and Communications in Medicine archive folder. Two observers evaluated the presence of Haller cells, AMO, and maxillary sinusitis in the CBCT scans.

Results

AMO was observed in 114 patients, of whom 27 (23.7%) had AMO exclusively on the right side, 26 (22.8%) only on the left side, and 61 (53.5%) bilaterally. Haller cells were identified in 73 (36.3%) patients. In 24 (32.9%) they were present exclusively on the right side, in 17 (23.3%) they were only present on the left side, and in 32 (43.8%) they were located bilaterally. Of the 73 (36.3%) patients with Haller cells, maxillary sinusitis was also present in 50 (68.5%). On using chi-square test, a significant association was observed between AMO and maxillary sinusitis in the presence of Haller cells.

Conclusion

Our results showed AMO and Haller cells to be associated with maxillary sinusitis. This study provides evidence for the usefulness of CBCT in imaging the bony anatomy of the sinonasal complex with significantly higher precision and a smaller radiation dose.

The incidence of concha bullosa, unusual anatomic variation and its relationship to nasal septal deviation: A retrospective radiologic study

OBJECTIVE

Identifying anatomical variations associated with pathological findings is very useful for diagnoses and therapeutics. We conducted a study to detect various anatomical variations (superior, middle, inferior turbinate concha bullosa, uncinate bulla and nasal swell body [NSB]) in connection with nasal septal deviation.

METHODS

This study used a retrospective radiological design to analyze 594 (1188 sides) osteomeatal computed tomography scans from 494 male patients and 100 female patients aged between 17 and 75 years. We randomly selected 100 male and 100 female patients as controls; we compared the groups and performed a statistical analysis. All patients in the control group had sinusitis only (i.e., they lacked nasal septal deviations).

RESULTS

Left-sided septal deviation was found to be slightly more prevalent than right-sided deviation (43.9% and 36.4%, respectively). The incidence of S-curved septal deviation was 18.5%, that of dorso-ventral deviation was 10.9%, and that of caudal-rostral deviation was 7.6%. The incidence of only septal spur was 1.2%. In the case of middle turbinate concha bullosa, the incidence of the unilateral type was 17.3% and that of the bilateral type was 36.4%. In superior turbinate concha bullosa, the incidence of the unilateral type was 11.3% and that of the bilateral type was 27.4%. The incidence of inferior turbinate concha bullosa was 1.0% and that of uncinate bulla was 1.7%. NSB was found in 25.1% of patients, 24.7% of males and 27.0% of females. The frequencies of middle and superior concha bullosa were about 10-12 fold higher on the concave side. The nasal septal deviation group exhibited a higher incidence of most anatomical variants than the non-deviated group; differences in the middle turbinate concha bullosa attained statistical significance.

CONCLUSION

The radiologist must focus on anatomical variants in the preoperative evaluation. It is important for surgeons to be aware of these variations.

The association of superior attachment of uncinate process with pneumatization of middle turbinate: a computed tomographic analysis

The frontal sinus outflow pathway is complex and can be influenced by the configuration of the uncinate process (UP). The UP can attach superior to the lamina papyracea, skull base, and middle turbinate. The factors associated with superior attachment remain unclear. This study analyzed the relationships between different types of superior UP attachment and characteristics of the surrounding structures including the agger nasi cell, skull base, and middle turbinate. This retrospective study utilized computed tomography images of 836 sides with identifiable sinus structure from 434 Taiwanese patients. Types of superior UP attachment, height of the ethmoid cribriform plate, prevalence of agger nasi cell, and degree of pneumatization of the middle turbinate were analyzed. In the current study, neither the presence of an agger nasi cell nor height of the cribriform plate had significant relationship with superior UP attachment type. However, UP attachment type was statistically significantly associated with pneumatized middle turbinate (PMT) type (p < 0.01). The PMT group had a higher incidence of UP attachment to the middle turbinate (38%) than the non-PMT group (18%). In the extensive PMT group, the incidence of UP attachment to the middle turbinate was high to 49%. In conclusion, superior UP attachment to the middle turbinate was associated with pneumatization of the middle turbinate. The UP has a greater tendency to attach to the middle turbinate in cases with more PMT.

The Effect of Nasal Obstruction after Different Nasal Surgeries Using Acoustic Rhinometry and Nasal Obstruction Symptom Evaluation Scale

BACKGROUND

The efficiency of nasal surgeries can be determined by objective or subjective methods. We have assessed the effect of nasal obstruction after different nasal surgeries using Acoustic Rhinometry (AR) and Nasal Obstruction Symptom Evaluation (NOSE) Scale.

METHODS

Between May 2011 and May 2012, 40 young adult patients and 10 healthy volunteers as control group who referred to Otorhinolaryngology Clinic in Eskisehir Military Hospital due to nasal obstruction were enrolled. Depending on operation, patients were divided into four equal groups. Group 1: Septoplasty, Group 2: Septoplasty with sprader graft, Group 3: Septorinoplasty and Group 4: Septorhinoplasty with spreader graft. The patients completed NOSE scale, 1 week before and 1 month after the surgery and AR measurements.

RESULTS

There were a significant improvement in mean NOSE scores of patients and statistical difference was found between pre and post-operational values for each group. There was a statistically significant change of the mean minimal cross section areas (MCA) of the deviated side of nasal passages measured by AR between pre and postoperative period.

CONCLUSION

In patients with nasal obstruction, functional nasal surgeries which were performed after appropriate medical examination and with right operation methods had a positive impact on quality of life and patient satisfaction. We observed that nasal findings were correlated with NOSE scores and MCA values. So, we suggest that NOSE scale and AR to be used for evaluation of the efficiency of functional nasal surgeries.

Assessing the prevalence of paranasal sinuses anatomical variants in patients with sinusitis using Cone Beam Computer Tomography

Background and aims

To asses, by using the Cone Beam CT (CBCT) reformatted images, the presence of anatomical variants of the sinonasal cavities and to determine the correlation of these variations with the onset of maxillary sinus inflammations.

Method

The study is a retrospective one and consists of the investigation of 130 patients with CBCT imaging, patients that were referred to the Maxillo-Facial Clinic, Radiology Department of the Iuliu Hatieganu University of Medicine and Pharmacy in Cluj-Napoca, for clinical symptoms of sinusitis within a period of 24 months. The images were analyzed for the presence of different anatomical variations and sinus inflammation. The CBCT images were obtained using a NewTom 3G scanner and the data acquired were statistically analyzed using Chi-square test, Odds ratio data and confidence intervals, with a determined p<0.05 considered to be statistically significant.

Results

The anatomical variants were detected both in the inflammation and control group. From the spectrum of variations concha bullosa, deviation of uncinate process and asymmetrical ethmoid roof presented significant association with sinusitis. The deviated position of the uncinate process appeared in more than 50% of patients in the positive group [OR=2.55] compared with a third of the control group. Concha bullosa was observed in 31% cases, 23% in the control group and 34% in the positive group [OR=1.73]. Haller cells showed a small difference between groups [OR=1.14] whereas the ethmoid roof asymmetry was evidently more prevalent in the inflammation group.

Conclusion

The anatomical variants of the paranasal sinuses are not incidental, being found in a large number of patients and may be a predisposing factor in the onset and recurrence of sinuses inflammation. The CBCT technique, due to the finest multiplanar reconstruction, permits a very good pre-therapeutic assessment of these predisposing conditions.

Frontal sinus asymmetry: Is it an effect of cranial asymmetry? X-ray analysis of 469 normal adult human frontal sinus

Background and Aims:

There is no study in the literature that investigates an asymmetric morphological feature of the frontal sinus (FS).

Materials and Methods:

Four hundred and sixty-nine consecutive direct X-rays of FSs were analyzed for the asymmetry between the right and left sides. When an asymmetry in the height and contour of the FS existed, this difference was quantified.

Results:

Of the 469 patients, X-rays of 402 patients (85.7%), there was an asymmetry between right and left sides of the FS. Of these 235 (50.1%) were dominant on the left side, whereas 167 (35.6%) were dominant on the right, the sinuses of remaining 67 patients (14.3%) was symmetric.

Statistical Analysis:

The comparisons between parameters were performed using Wilkinson signed rank test. The relationship between handedness and sinus asymmetry was also examined by two proportions test. There is statistically significant difference between the dominance of left and right FS.

Conclusions:

Hemispheric dominance may have some effect (s) of on sinus asymmetry of the human cranium. Surgeons sometimes enter the cranium through the FS and knowledge of asymmetric FS is important to minimize surgical complications.

Epidemiology of chronic rhinosinusitis, selected risk factors, comorbidities, and economic burden

Chronic rhinosinusitis (CRS) is a relevant and prevalent medical condition in Germany, Europe and the world. If analysed in detail, the prevalence of CRS shows regional and temporary variety. In this review, currently available data regarding the prevalence of CRS is therefore sorted by country and/or region, time point of data collection and the CRS-definition employed. Risk factors like smoking and gastroesophageal reflux are discussed regarding their influence on CRS prevalence. Moreover, comorbidities of CRS, like asthma, conditions of the cardiovascular system and depression are listed and their influence on CRS is discussed. Furthermore, data on CRS prevalence in special cohorts, like immunocompromised patients, are presented. To estimate the economic burden of CRS, current data e.g. from Germany and the USA are included in this review.

Identification of Onodi cell and new classification of sphenoid sinus for endoscopic sinus surgery

BACKGROUND

There is no effective classification method for the opening of the sphenoid sinus. The objective of this study was to examine the effectiveness of identification of the Onodi cell and classification of the sphenoid sinus using sagittal computed tomography (CT) for sphenoidotomy.

METHODS

CT images of the sinuses of surgical patients (n = 261; 522 sides) were studied. Using sagittal CT, the relationships between the lateral side of the anterior wall of the sphenoid sinus and the optic nerve, and between the middle of the anterior wall of the sphenoid sinus and the skull base or pituitary gland were studied. Images were classified as demonstrating skull base (without the Onodi cell), optic canal, sella, or infra-sella (all with the Onodi cell) type.

RESULTS

Two hundred and fifty-eight sides (49.2%) were of the skull-base type, 181 (34.7%) were of the optic-canal type, 58 (11.1%) were of the sella type, and 26 (5.0%) were of the infra-sella type; ie, the Onodi cell was present in 50.8% of sides. The width of the anterior wall of the sphenoid sinus became narrower as it shifted from the skull-base type to the infra-sella type.

CONCLUSION

Classification of the anterior wall of the sphenoid sinus based on the Onodi cell allows 3-dimensional assessment of the shape of the sphenoid sinus. We believe that the sphenoid sinus can be opened safely by full preoperative assessment of the anterior wall type, the position of the superior turbinate, and the position of the ostium of the sphenoid sinus.

Anatomical Variations of Ostiomeatal Complex in CBCT of Patients Seeking Rhinoplasty

STATEMENT OF THE PROBLEM

Anatomic variation can potentially impact the surgical safety.

PURPOSE

The purpose of this cross-sectional study was to assess the prevalence of ostiomeatal complex variations based on cone beam computed tomography (CBCT) images of the patients seeking rhinoplasty.

MATERIALS AND METHOD

In this cross-sectional study, CBCT images of 281 patients including 153 female and 128 male with Mean±SD age of 26.97±7.38 were retrieved and analyzed for presence of variations of ostiomeatal complex and mucosal thickening. All CBCT images were acquired by NewTom VGi scanner with 15×15 field of view, as a part of preoperative recording of patients seeking rhinoplasty in an otolaryngology clinic. Chi- square test and Odds ratio were used for statistical analysis of the obtained data and p< 0.05 was considered to be statistically significant.

RESULTS

Agger nasi cells which were seen in 93.2% of the cases were the most common anatomic variation. It was followed by Haller cells (68%), concha bullosa (67.3%), uncinate process variations (54.8%), nasal sepal deviation (49.5%) and paradoxical curvature of middle turbinate (10%). Mucosal thickening were detected in 60.7% of the studied cases.

CONCLUSION

Ostiomeatal complex variations and mucosal thickening are considerably prevalent among the patients seeking rhinoplasty. This study also revealed that CBCT evaluation of paranasal sinuses has comparable result in delineation of the sinonasal anatomy.

An analysis of the anatomic variations of the paranasal sinuses and ethmoid roof using computed tomography

OBJECTIVE

To determine the Keros classification and asymmetrical distribution rates of the ethmoid roof and the frequency of anatomic variations of the paranasal sinuses.

MATERIALS AND METHODS

Paranasal sinus scans of 500 patients obtained using computed tomography were evaluated retrospectively. Measurements were performed using a coronal plan with right-left comparison and with distance measurement techniques. The depth of the lateral lamella was calculated by subtracting the depth of the cribriform plate from the depth of the medial ethmoid roof. The results were classified according to their Keros classification. Any asymmetries in the ethmoid roof depth and fovea ethmoidalis configuration were examined. The anatomic variations frequently encountered in paranasal sinuses (pneumatized middle concha, paradoxical middle concha, agger nasi cells, Haller cells, Onodi cells, etc.) were defined.

RESULTS

The mean height of the lateral lamella cribriform plate (LLCP) was 4.92±1.70 mm. The cases were classified as 13.4% Keros Type I, 76.1% Keros Type II, and 10.5% Keros Type III. There was asymmetry in the LLCP depths of 80% of the cases, and a configuration asymmetry in the fovea in 35% of the cases. In 32% of the cases with fovea configuration asymmetry, there was also asymmetry in the height of the right and left LLCP. The most frequent variations were nasal septum deviation (81.8%), agger nasi cells (63.8%), intralamellar air cells (45%), and concha bullosa (30%).

CONCLUSION

Using the Keros classification for LLCP height, higher rates of Keros Type I were found in other studies than in our study. The most frequent classification was Keros Type II. The paranasal sinus variations in each patient should be carefully evaluated. The data obtained from these evaluations can prevent probable complications by informing rhinologists performing endoscopic sinus surgery about preoperative and intraoperative processes.

A Study of Anatomical Variations of Osteomeatal Complex in Chronic Rhinosinusitis Patients-CT Findings

BACKGROUND

Chronic rhino sinusitis (CRS) is the most common disease for which consultation of otorhinolaryngologist is sought. The approach to patients with chronic rhino sinusitis is endoscopic surgery which aims at removing the obstruction of the main drainage pathway. The osteomeatal complex based essentially on the concept that such obstruction perpetuates the sinus disease. This in turn requires the surgeons to have detailed knowledge of the anatomy of the lateral nasal wall, paranasal sinuses and surrounding vital structures and of the large number of anatomical variants in the region.

AIM

To study anatomical variations of osteomeatal complex in chronic sinusitis patients.

MATERIALS AND METHODS

Descriptive cross-sectional study design in which 54 consecutive cases of chronic rhino sinusitis patients attending the ENT outpatient department, who had chronic sinusitis for more than three months duration not responding to the medical line of treatment and who were willing to undergo Functional Endoscopic Sinus Surgery satisfying the inclusion criteria were studied. The results were expressed in percentage and proportions.

RESULTS

In our study it was observed that 53.7% of the chronic sinusitis cases had two or more anatomical variations and 33.3% of the cases had single anatomical variation. Deviated nasal septum was found to be the most common amongst the anatomical variations in chronic sinusitis cases in the present study which was followed by unilateral concha bullosa and paradoxically bent middle turbinate. Agger nasi cell and Haller cell were seen in one case each.

CONCLUSION

Prevalence of multiple anatomical variations was more in our study in comparison to single anatomical variation. Deviated nasal septum was the most common anatomical variation encountered in our study followed by concha bullosa.

Analysis of the Agger nasi cell and frontal sinus ostium sizes using computed tomography of the paranasal sinuses

The Agger nasi cell (ANC) and the frontal sinus ostium (FO) are important structures that can influence the anatomy and physiology of the frontal recess. The aim of this study was to evaluate the presence and size of ANC and the FO and correlate them according to gender, race and among themselves.

Method

A prospective study with 40 patients who underwent CT of the paranasal sinuses with sagittal reconstruction. Measurements: ANC (APAN) anteroposterior diameter, ANC (CCAN) craniocaudal diameter, ANC (LLAN) side-to-side diameter, anteroposterior diameter of the FO (APFO) and side-to-side diameter of the FO (LLFO).

Results

Twenty-two patients were male and 18 females, mean age 33.7 years. Most patients were white (45%), followed by browns (32.5%), blacks (20%) and asians (2.5%). The ANC was present in 98.7% of patients. There was statistical difference for APAN on females and LLAN on females and on the total sample. There were no differences for all measurements regarding gender, as well as the race. ANC and FO measurements showed positive correlation, but poor or very poor.

Conclusion

The prevalence of ANC in our sample was high and did not show a statistically significant difference for most measurements. The correlation between measurements of ANC and the FO was poor or very poor.

Cone beam CT analysis of Haller cells: prevalence and clinical significance

OBJECTIVES

Haller cells are anterior ethmoid air cells located in the medial orbital floor immediately lateral to the maxillary infundibulum. The purpose of this study was to demonstrate the prevalence and relationship between the existence and size of these cells with ipsilateral maxillary sinusitis and orbital floor dehiscence as visualized on cone beam CT (CBCT) images.

METHODS

CBCT image volumes of 50 patients were retrieved and analysed. All CBCT images were acquired with a 9-inch field of view scan. χ(2) and Cochran-Mantel-Haenszel tests were used for statistical analysis of the obtained data, and p-values of <0.05 were considered to be statistically significant.

RESULTS

There was no statistically significant association between the existence and size of Haller cells and maxillary sinusitis. There was a significant association between Haller cells and orbital floor dehiscence.

CONCLUSIONS

The explanation of maxillary sinusitis on the basis of mechanical obstruction is unlikely. This study provides evidence for the usefulness of CBCT scan in delineation of the sinonasal anatomy.

Comparison of cone-beam computed tomography incidental findings between patients with moderate/severe obstructive sleep apnea and mild obstructive sleep apnea/healthy patients

OBJECTIVE

The objective of this study was to compare the incidental radiographic findings in the maxillofacial structures and the pharyngeal airway between subjects with moderate/severe obstructive sleep apnea (OSA) and mild OSA/healthy subjects using cone-beam computed tomography (CBCT) scans.

STUDY DESIGN

A total of 53 subjects with moderate/severe OSA (with a Respiratory Disturbance Index [RDI] ≥ 15 events/h) and 33 mild OSA/healthy subjects (RDI < 15), based on ambulatory somnographic assessment, were recruited. Supine CBCTs were taken and sent for radiological report. The incidental findings were compared between the 2 groups.

RESULTS

Moderate/severe subjects had larger prevalence of conchae bullosa, hypertrophic turbinates, hypertrophic tonsils, elongated or posteriorly placed soft palate, narrower airway, enlarged tongue, and focal calcifications, although no significant differences were found.

CONCLUSIONS

CBCT is useful in identifying maxillofacial and airway anomalies that could interfere with normal breathing; however, no significant difference was found in prevalence of incidental findings between subjects with moderate/severe OSA and mild OSA/healthy subjects. Further studies are necessary to generalize our results.

There is no structural relationship between nasal septal deviation, concha bullosa, and paranasal sinus fungus balls

This study aims to determine the relationship between nasal septal deviation, concha bullosa, and chronic rhinosinusitis by using a definitive pathological and simplified model. Fifty-two consecutive sinus computed tomography scans were performed on patients who received endoscopic sinus surgery and whose final diagnosis was paranasal sinus fungus balls. The incidences of nasal septal deviation and concha bullosa for patients diagnosed with paranasal sinus fungus balls among the study group were 42.3% and 25%, respectively. About 63.6% sinuses with fungus balls were located on the ipsilateral side of the nasal septal deviation, and 46.2% were located on the ipsilateral side of the concha bullosa. When examined by Pearson's chi-square test and the chi-squared goodness-of-fit test, no significant statistical difference for the presence of paranasal sinus fungus balls between ipsilateral and contralateral sides of nasal septal deviation and concha bullosa was noted (P = 0.292 and P = 0.593, resp.). In conclusion, we could not demonstrate any statistically significant correlation between the location of infected paranasal sinus, the direction of nasal septal deviation, and the location of concha bullosa, in location-limited rhinosinusitis lesions such as paranasal sinus fungal balls. We conclude that the anatomical variants discussed herein do not predispose patients to rhinosinusitis.

The relationship between pneumatized middle turbinate and the anterior ethmoid roof dimensions: a radiologic study

The development of pneumatized middle turbinate may affect anterior ethmoid roof formation. The aim of this study was to investigate the relationship between the pneumatized middle turbinate and the dimensions of the anterior skull base structures using computed tomography scans. The coronal reconstructed images of the computed tomography scans were evaluated retrospectively. The lateral and medial ethmoid roof points, the width of the cribriform plate (CP), and the anterior ethmoid roof were identified at the first coronal cut, which was determined by the infraorbital nerve. The pneumatized middle turbinates were measured on the axial, vertical, and sagittal planes. The images of 101 patients were evaluated. The mean axial diameters of the pneumatized middle turbinate on the right and left sides were between 6.93 and 4.95 mm, respectively. The correlation between the axial diameters of the pneumatized middle turbinate and the width of the anterior ethmoid roof (termed AER width) was significant for both sides and gender (p < 0.05). There was a higher correlation on the right side where the pneumatized middle turbinate was observed more frequently (r = 0.357). The relationship between CP width and the diameters of the pneumatized middle turbinate was not significant (p > 0.05) for both sides. Iatrogenic lesions of the skull base occur predominantly in the lateral lamella of the CP. The risk of this complication may decrease with increasing of the AER width. Pneumatized middle turbinate may cause an increase in the width of the anterior ethmoid roof and provide more reliable endoscopic intervention of the anterior skull base and frontal sinus.

High-resolution computed tomography analysis of the prevalence of Onodi cells

OBJECTIVES/HYPOTHESIS

Onodi cells are the posterior-most ethmoid air cells that lie superior to the sphenoid sinus. Identification of these cells is essential prior to endoscopic sinus and skull base surgery due to their intricate relationship with the optic nerves and carotid arteries, which may lead to deleterious complications. In this study, high-resolution computed tomography (HRCT) scans from 170 adult-patients were analyzed by two independent observers for the presence of Onodi cells.

STUDY DESIGN

Radiographic analysis at a tertiary care medical center.

METHODS

A retrospective analysis was performed on patients undergoing HRCT between July 2008 and September 2010. Incidence of Onodi cells and demographic data were collected.

RESULTS

The overall prevalence of Onodi cells in this cohort was 65.3%. Subgroup analysis based on ethnicity showed a rate of Onodi cells of 83.3% in Asians, 73.1% in whites, 57.0% in African Americans, and 62.7% in Hispanics. The prevalence of Onodi cells was not significantly different among the different ethnicities (P > .05). However, this was limited by a small sample size in some ethnic groups. Onodi cell prevalence was equivalent among males and females: 62.2% and 63.5% respectively (P > .05). Overall, our results show a greater prevalence of Onodi cells than previously reported.

CONCLUSIONS

We found a higher prevalence of Onodi cells in our cohort than previously reported in the literature. Therefore, it is important for surgeons to anticipate the presence of these cells during endoscopic sinus and skull base procedures to prevent potential complications.

Prevalence of pathologic findings in the maxillary sinus in cone-beam computerized tomography

OBJECTIVE

The aim of this study was to assess the prevalence of pathologic findings in the maxillary sinus by using cone-beam computerized tomography (CBCT).

STUDY DESIGN

One thousand twenty-nine consecutive CBCT scans were retrospectively inspected for pathologic findings in the maxillary sinus by 3 observers. Findings were differentiated by mucosal thickening, partial opacification with liquid accumulation, total opacification, and polypoidal mucosal thickening. Position and diameter of the maxillary sinus ostium were assessed. Correlations for pathologic findings and the factors of age and gender were calculated. Patients with clinical manifestations of sinusitis or total opacification in either sinus were reevaluated.

RESULTS

A total prevalence for pathologies in the maxillary sinus of 56.3% was found in this study. The most frequent pathology was mucosal thickening. Patients >60 years of age showed significantly more pathologies in the maxillary sinus (P = .02), and male patients showed significantly more pathologies than female patients (P = .01). Clinical signs of sinusitis could be confirmed on CBCT images for all patients.

CONCLUSIONS

Pathologies in the maxillary sinus are frequently found in CBCT imaging and have to be treated or followed-up accordingly. CBCT is applicable for diagnosis and treatment planning of clinically present sinusitis.

Role of surgery in isolated concha bullosa

Objective:

To study the benefit of surgery in different types of isolated concha bullosa.

Design:

Prospective case series.

Setting:

Academic Medical Center.

Patients:

Forty seven symptomatic patients complaining of nasal congestion and block, headache and facial pain having concha bullosa without any other sinonasal finding. Their conchae bullosa were classified as lamellar, bulbous and extensive concha bullosa. They were subjected to endoscopic operation.

Main outcome measures:

Subjective evaluation of postoperative improvement of sinonasal symptoms and objective pre- and postoperative measurement of total nasal resistance by rhinomanometry.

Results:

Two patients (25%) of lamellar type showed complete improvement, 5 patients (62.5%) showed partial improvement and 1 patient (12.5%) showed no improvement. Regarding bulbous type, 16 patients (72.72%) showed complete improvement, 6 patients (27.28%) showed partial improvement and no patient (0%) showed no improvement. Regarding extensive type, 15 (88.24%) patients showed complete improvement, 2 patients (11.76%) showed partial improvement and no patient (0%) showed no improvement. The total nasal resistance was 0.25 Pa/cm³ per second postoperatively compared with 0.37 Pa/cm³ per second preoperatively in patients having lamellar type; 0.28 Pa/cm³ per second postoperatively compared with 0.71 Pa/cm³ per second preoperatively in patients having bulbous type; and 0.27 Pa/cm³ per second postoperatively compared with 0.67 Pa/cm³ per second preoperatively in patients having extensive type.

Conclusions:

With proper patient selection, the operative management is of great value in relieving the sinonasal symptoms in patients having isolated Concha bullosa. This will be more obvious in certain types as bulbous and extensive types especially of large sizes.

A quite rare condition: absence of sphenoidal sinuses

The absence of sphenoidal sinuses (SS) in an adult is an extremely rare condition. We investigated in agenesis of the sphenoid, maxillary, ethmoid, and frontal sinuses in 20 male adult cadavers. In a 50-year-old man, bilateral absence of the SS was observed. On the macroscopic examination, opening of the SS was not found on the lateral wall of the nasal cavity. There were multiple small mucosal grooves between the sphenoidal rostrum and the superior nasal turbinates. The bulging of the sphenoidal rostrum at the choanal level was flat. The body of the sphenoid bone was normal and consisted of a symmetrical bony structure with a total lack of pneumatization. Other paranasal sinuses agenesis was not observed. Surgeons should also consider the possibility of sphenoidal agenesis before transsphenoidal hypophysectomy. As a supplement to the traditional classification, agenesis of the SS can be described as the fourth type of pneumatization.

CT scan evaluation of the anatomical variations of the ostiomeatal complex

INTRODUCTION

Functional endoscopic sinus surgery (FESS) has revolutionized the approach and treatment of chronic rhinosinusitis. Certain anatomical variations are thought to be predisposing factors for the development of sinus disease and it is necessary, for the surgeon to be aware of these variations, especially if the patient is a candidate for FESS.

OBJECTIVE

The aim of the present study was to identify the various anatomical variations of the ostiomeatal complex in patients of chronic rhinosinusitis who underwent FESS.

MATERIALS AND METHODS

A total of 150 patients of chronic rhinosinusitis (medical treatment failures) who were subjected to FESS were CT scanned preoperatively to find any bony anatomic variation and the extent of mucosal disease.

RESULTS

Concha bullosa was the commonest anatomic variation and was seen in 45 (30%) patients. The other anatomic variations noted included: paradoxical middle turbinate in 9.33% patients, uncinate process variations in 25% patients, agger nasi cells in 9.33%, Haller cells in 8.66% and posterior septal deviations in 25.33% patients. The mucosal disease was most commonly seen in anterior ethmoids (87.33% ), followed by maxillary sinus ostial area (70%), maxillary sinus disease (65.33%), posterior ethmoidal disease (38%), frontal sinus disease (15%) and sphenoid sinus mucosal disease (8.66%) patients.

CONCLUSION

A thorough preoperative CT evaluation of the patients undergoing FESS is necessary to detect various anatomical variations in the ostiomeatal complex.

CT-based manual segmentation and evaluation of paranasal sinuses

Manual segmentation of computed tomography (CT) datasets was performed for robot-assisted endoscope movement during functional endoscopic sinus surgery (FESS). Segmented 3D models are needed for the robots' workspace definition. A total of 50 preselected CT datasets were each segmented in 150-200 coronal slices with 24 landmarks being set. Three different colors for segmentation represent diverse risk areas. Extension and volumetric measurements were performed. Three-dimensional reconstruction was generated after segmentation. Manual segmentation took 8-10 h for each CT dataset. The mean volumes were: right maxillary sinus 17.4 cm(3), left side 17.9 cm(3), right frontal sinus 4.2 cm(3), left side 4.0 cm(3), total frontal sinuses 7.9 cm(3), sphenoid sinus right side 5.3 cm(3), left side 5.5 cm(3), total sphenoid sinus volume 11.2 cm(3). Our manually segmented 3D-models present the patient's individual anatomy with a special focus on structures in danger according to the diverse colored risk areas. For safe robot assistance, the high-accuracy models represent an average of the population for anatomical variations, extension and volumetric measurements. They can be used as a database for automatic model-based segmentation. None of the segmentation methods so far described provide risk segmentation. The robot's maximum distance to the segmented border can be adjusted according to the differently colored areas.