Examination of ethmoidal roof regarding Keros and Yenigun classifications in a Turkish population: a computerized tomography study.

PURPOSE: Understanding ethmoid roof morphology is crucial to prevent complications in endoscopic sinus surgery. This study aimed to evaluate the morphological properties of the ethmoidal roof regarding gender and age differences using Keros and Yenigun classifications on high-resolution computed tomography images. METHODS: We retrospectively analyzed 891 high-resolution computed tomography paranasal sinus study images and measured the depth of the cribriform plate in coronal sections and the anterior-posterior length in axial planes. The study retrospectively examined CT images of paranasal sinuses of patients living in the eastern Anatolian region of Turkey. RESULTS: In both Keros and Yenigun Classifications, the most common class was type 2, and the least common class was type 3. According to Keros et al.'s method, no significant difference was observed between men and women (p = 0.698). However, according to Yenigun et al., the average values of women in terms of the anterior-posterior distance of the ethmoid roof were significantly higher than men (p = 0.001). When examined according to age, a very low, negative correlation was revealed regarding Keros and Yenigun classifications (p = 0.047 and p < 0.001 retrospectively). According to Keros and Yenigun's classification, there was no significant difference between the left and right sides (p = 0.488 and p = 0.919, respectively). CONCLUSION: The morphological properties of the ethmoidal roof have importance to be considered for preoperative planning. Studying larger patient groups and meta-analyses that gather various research results about this subject might help better understand the ethmoidal roof morphology among populations.

Growth and microanatomy of the paranasal sinuses in two species of New World monkeys.

Paranasal sinuses of living apes and humans grow with positive allometry, suggesting a novel mechanism for bone enlargement. Here, we examine the paranasal sinuses of the owl monkey (Aotus spp.) and a tamarin (Saguinus midas) across postnatal development. The prediction that paranasal sinuses grow disproportionately faster than the main nasal chamber is tested. We used diffusible iodine-based contrast-enhanced computed tomography and histology to study sinuses in eight Aotus and three tamarins ranging from newborn to adult ages. Sinuses were segmented at the mucosa-air cavity interface and measured in volume. All sinuses were lined by a ciliated respiratory epithelium, except for the ethmoid air cells in Aotus, which are lined in part by olfactory epithelium. An age comparison indicates that only the maxillary sinus and ethmoid air cells are present in newborns, and two additional sinuses (invading the orbitosphenoid and the frontal bone), do not appear until late infancy or later. Comparing newborns and adults, the main nasal airway is 10 times larger in the adult Aotus and ~ 6.5 times larger in adult Saguinus. In contrast, the maxillary sinus far exceeds this magnitude of difference: 24 times larger in the adult Aotus and 46 times larger in adult Saguinus. The frontal sinuses add significantly to total paranasal space volume in both species, but this growth is likely delayed until juvenile age. Results suggest ethmoid air cells expand the least. These results support our prediction that most paranasal sinuses have a distinctly higher growth rate compared to the main nasal chamber.

Advancements in acoustic drug delivery for paranasal sinuses: A comprehensive review.

Chronic rhinosinusitis (CRS) impacts patients' quality of life and healthcare costs. Traditional methods of drug delivery, such as nasal sprays and irrigation, have limited effectiveness. Acoustic Drug Delivery (ADD) using a nebulizer offers targeted delivery of drug to the sinuses, which may improve the treatment of CRS. This review examines the influence of aerosol particle characteristics, aero-acoustic parameters, inlet flow conditions, and acoustic waves on sinus drug delivery. Key findings reveal that smaller particles improve the ADD efficiency, whereas larger sizes or increased density impair it. The oscillation amplitude of the air plug in the ostium is crucial for the ADD efficiency. Introducing acoustic waves at the NC-sinus system's resonance frequency improves aerosol deposition within sinuses. Future research should address advanced models, optimizing particle characteristics, investigating novel acoustic waveforms, incorporating patient-specific anatomy, and evaluating long-term safety and efficacy. Tackling these challenges, ADD could offer more effective and targeted treatments for sinus-related conditions such as CRS.

A Systematic Literature Study of the Sinus Septi Nasi, Crista Galli and Other Minor Pneumatizations / Estudio Bibliográfico Sistemático del Seno Septi Nasi, Crista Galli y Otras Neumatizaciones Menores

SUMMARY: Variations in the paranasal sinuses and pneumatizations originating from these structures are clinically important for surgical procedures to be performed in the nose and nasal cavity regions. No systematic review examining the sinus septi nasi, crista galli and other minor pneumatizations was found in the literature review. This study aimed to review the papers in the literature including the sinus septi nasi, crista galli and other minor pneumatizations and standardize the mean incidence, distribution by sex, age and origin of these structures. Furthermore, it was aimed to examine the height, length, and width values of sinus septi nasi and crista galli pneumatizations, determine the measurement intervals and measurement values, and standardize them. The studies involving these pneumatizations were reviewed from various databases. After being evaluated according to the inclusion and exclusion criteria, 35 articles between the years 1991-2021 were reviewed. Based on the data obtained from these articles, we examined the incidence of sinus septi nasi, crista galli, and other minor pneumatizations. Middle nasal turbinate pneumatization had the highest incidence among all these pneumatizations. Uncinate process pneumatization had the lowest incidence. Considering the distribution by sex, no difference was found. Upon examining the age range, there were people aged between 1-95 years, and the mean age range was 33.05-41.48. The length, width and height values of crista galli and sinus septi nasi could not be standardized due to the insufficient number of studies and variable data in the literature. We believe that our study will contribute to similar future studies in larger populations with the clinical procedures to be performed in and around the nasal cavity.

Las variaciones en los senos paranasales y las neumatizaciones que se originan en estas estructuras son clínicamente importantes para los procedimientos quirúrgicos que se realizan en las regiones de la nariz y la cavidad nasal. En la revisión de la literatura no se encontró ninguna revisión sistemática que examinara el seno septi nasi, la crista galli y otras neumatizaciones menores. Este estudio tuvo como objetivo revisar los trabajos en la literatura que incluyen el seno septi nasi, la crista galli y otras neumatizaciones menores y estandarizar la incidencia media, la distribución por sexo, edad y origen de estas estructuras. Además, tuvo como objetivo examinar los valores de altura, longitud y ancho de las neumatizaciones del seno septi nasi y crista galli, determinar los intervalos de medición y los valores de medición, y estandarizarlos. Los estudios relacionados con estas neumatizaciones se revisaron a partir de varias bases de datos. Luego de ser evaluados según los criterios de inclusión y exclusión, se revisaron 35 artículos entre los años 1991-2021. Sobre la base de los datos obtenidos de estos artículos, examinamos la incidencia de septi nasi nasi, crista galli y otras neumatizaciones menores. La neumatización de la concha nasal media tuvo la mayor incidencia entre todas estas neumatizaciones. La neumatización del proceso uncinado tuvo la menor incidencia. Considerando la distribución por sexo, no se encontró diferencia. Al examinar el rango de edad, había personas con edades entre 1 y 95 años, y el rango de edad promedio fue de 33,05 a 41,48. Los valores de longitud, ancho y altura de crista galli y seno septi nasi no pudieron estandarizarse debido a la cantidad insuficiente de estudios y datos variables en la literatura. Creemos que nuestro estudio contribuirá a futuras investigaciones similares en poblaciones más grandes con los procedimientos clínicos que se realizarán en y alrededor de la cavidad nasal.

Validation of a three-dimensionally printed simulator for training in endoscopic sinonasal surgery.

BACKGROUND: The ability to incorporate different materials in the construction of 3-D printed models has resulted in the ability to mimic a variety of anatomical structures such as cartilage, mucosa and bone. The aim of this study was to evaluate the face and content validities of a model as a training tool for endoscopic sinus surgery. METHODS: Twenty-six delegates and ten teaching faculty members were invited to complete a post-hoc questionnaire survey. The survey consisted of a 22-question 5-point Likert scale to assess the model's realism (face validity) and its effectiveness as a training tool (content validity). RESULTS: Over 80% of the delegates agreed or strongly agreed that the appearance of anatomical structures within the model was realistic and mimicked actual sinus anatomy. In addition, a similar proportion agreed or strongly agreed that the application of instruments on the composite materials of the model realistically mimicked bone. All faculty agreed that the model was useful to develop hand-eye coordination and was a useful training tool for endoscopic sinus surgery. Overall, the sinus model received high scores regarding its use for training surgeons, especially to develop camera and instrument handling skills. CONCLUSION: The results of this study suggest that otolaryngology doctors in their early or intermediate stage of training would benefit most from a clinical-based modular programme. The model requires further development in areas such as the realism of mucosa, incorporation of sinonasal pathology and having more complex anatomy to be useful for the training of more advanced surgeons.

Normal and Variant Sinonasal Anatomy.

The anatomy of the paranasal sinuses is complex with multiple anatomic variants that can predispose patients to disease. Knowledge of this complex anatomy is important not only for successful treatment but to also avoid complications at the time of surgery. This article will review the anatomy with emphasis on a variety of clinically important anatomic variants.

An anatomical study of the skull, the dorsal and ventral nasal conchal bullae and paranasal sinuses in normal Noma horses: Computed tomographic anatomical and morphometric findings.

Noma horses have the smallest body size among native Japanese horses and are classified as pony breeds by their size. Additionally, the Japanese horse breeds are classified into a single lineage, which includes Mongolian horses. Great intraspecific differences reportedly exist in the head shapes of domesticated horses, which have been investigated in various horse breeds. The present study aimed to evaluate the size of the nasal conchal bullae, and the paranasal sinuses of Noma horses in relation to the skull dimensions using computed tomography. Reconstructed images of the heads of five adult Noma horses were used. Skull and paranasal sinus parameters were measured and analysed in relation to each other and were compared with the data in the literature on the skulls of various horse breeds. In comparison with pony breed, Shetland ponies and donkeys had a shorter nasal length than cranial length, while Noma horses had a longer nasal length than cranial length, similar to the larger breeds. In the nasal conchal bullae, Shetland ponies showed a negative correlation between the head and bullae size, while Noma horses, similar to larger breeds, had a positive correlation. In conclusion, our findings suggest that Noma horses, despite having a body size that belongs to the pony breed, had a distinguishing ratio of the skull and paranasal sinuses similar to that of the larger breeds. Our results provide information on the physiological morphology of the head and comparative anatomy based on genetic diversity in horses.

CT anatomy of the head in the Ile de France sheep.

BACKGROUND: CT scan images provide accurate anatomical data from different areas of the body that can be used to diagnose diseases. OBJECTIVES: The present work aimed to describe the normal anatomical structures of the Ile de France sheep head and its morphometric and volumetric properties using computed tomography (CT) and stereological methods. METHODS: Five adult Ile de France sheep heads, which were of mature age (above 10 months), were included in this study. The different cavities of the head, including the nasal cavity, paranasal sinuses, oral cavity, orbital cavity and vestibulocochlear system, were evaluated using CT scans, cross, sagittal and coronal sections. RESULTS: The mean length, height and width of the skull were 25.3 ± 1.02, 9.8 ± 0.93 and 12.3 ± 0.91 cm, respectively. The results showed that the nasal cavity is divided into three regions. Vestibular, respiratory and olfactory regions. The paranasal sinuses are composed of maxillary, frontal, palatine, sphenoid, lacrimal and ethmoidal that were identified and named in the CT scan images and their corresponding anatomical cross-sections. The total volume of the head, nasal cavity and oral cavity was estimated to be 2998 ± 202.00, 303 ± 31.33 and 229.3 ± 10.61 cm3 , respectively. CONCLUSIONS: The frontal sinus in the Ile de France sheep was limited to the frontal bone without extending into the parietal, temporal, or occipital bones, similar to Saanen goat. This study provided a comprehensive atlas of Ile de France sheep anatomy to internal medicine veterinarians and surgeons.

Pediatric paranasal sinuses-Development, growth, pathology, & functional endoscopic sinus surgery.

The paranasal sinuses (maxillary, frontal, ethmoid, and sphenoid sinuses) are complex anatomical structures. The development and growth of these have been investigated utilizing a number of different methods ranging from cadaveric analysis to modern cross sectional imaging with 3D modeling. An understanding of normal pediatric paranasal sinus embryology and development enables us to better determine when pathology may be affecting the normal developmental process. Cystic fibrosis, chronic sinusitis, deviated nasal septum and cleft lip and palate are some of the conditions which have been shown to effect paranasal sinus development to varying degrees. Functional endoscopic sinus surgery (FESS) is becoming increasingly common and an understanding of sinus anatomy together with when periods of rapid growth occur during childhood is important clinically. Although concerns have been raised regarding the impact of FESS on facial growth, there is limited evidence of this in regards to either changes in anthropomorphic measurements or clinical assessments of symmetry post operatively.

Variations in Paranasal Sinus Anatomy in Children With Apert Syndrome: A Radiological Analysis.

BACKGROUND: Apert syndrome is a genetic disorder characterized by craniofacial abnormalities and premature closure of the coronal sutures. The restriction of cranial development may have a subsequent effect on paranasal anatomy development. AIM: The aim of the study was to gain an understanding of paranasal sinus anatomical variations seen in children with Apert syndrome. MATERIALS AND METHODS: This was a retrospective review of computed tomography and magnetic resonance images of children with Apert syndrome from 2000 to 2020. Images were reviewed to identify anatomical variations in paranasal sinus anatomy. RESULTS: Twenty-one patients were included in the study. The most commonly seen variation was septal deviation in 86% of cases, with 60% of patients having a septal defect. The presence of protrusion or dehiscence of the infraorbital nerve, carotid canal and Vidian nerve, and presence of a concha bullosa were not observed in any patients. Keros type I was the most commonly observed olfactory fossa depth in 79% of patients, and type I Kuhn cells were observed in 83% of patients. CONCLUSIONS: To our knowledge, this is the first study which describes the prevalence of variations in paranasal sinus anatomy found in children with Apert syndrome. Septal deviation, type I Kuhn cells and Keros type I olfactory fossa depth were observed in a higher prevalence in our cohort than in the general population. As such, assessment for the presence of chronic rhinosinusitis and nasal obstruction should be evaluated as part of the multidisciplinary assessment.

Nasosinusal Endoscopic Anatomy and Physiology

The present article focuses on the analysis of the nasal cavity's anatomy succinctly and descriptively. This essay was carried out through a bibliographic review, directed to the detailed anatomy of the nasal cavity, and the structures that form its sinuses. We have identified the need formore studies directed to the related anatomical area so that the improved knowledge of this region ensures a nasoendoscopic treatment with better effectiveness and no complications.

Comparison of Sinus Deposition from an Aqueous Nasal Spray and Pressurised MDI in a Post-Endoscopic Sinus Surgery Nasal Replica.

BACKGROUND: Optimising intranasal distribution and retention of topical therapy is essential for effectively managing patients with chronic rhinosinusitis, including those that have had functional endoscopic sinus surgery (FESS). This study presents a new technique for quantifying in vitro experiments of fluticasone propionate deposition within the sinuses of a 3D-printed model from a post-FESS patient. METHODS: Circular filter papers were placed on the sinus surfaces of the model. Deposition of fluticasone on the filter paper was quantified using high-performance liquid chromatography (HPLC) assay-based techniques. The deposition patterns of two nasal drug delivery devices, an aqueous nasal spray (Flixonase) and metered dose inhaler (Flixotide), were compared. The effects of airflow (0 L/min vs. 12 L/min) and administration angle (30° vs. and 45°) were evaluated. RESULTS: Inhaled airflow made little difference to sinus deposition for either device. A 45° administration angle improved frontal sinus deposition with the nasal spray and both ethmoidal and sphenoidal deposition with the inhaler. The inhaler provided significantly better deposition within the ethmoid sinuses (8.5x) and within the maxillary sinuses (3.9x) compared with the nasal spray under the same conditions. CONCLUSION: In the post-FESS model analysed, the inhaler produced better sinus deposition overall compared with the nasal spray. The techniques described can be used and adapted for in vitro performance testing of different drug formulations and intranasal devices under different experimental conditions. They can also help validate computational fluid dynamics modelling and in vivo studies.

Computed Tomography Image Analysis and Clinical Correlations of Retromaxillary Cells.

OBJECTIVE: This study aimed to investigate and analyze the anatomic characteristics of the retromaxillary cell (RMC) by using computed tomography (CT) images of paranasal sinuses and to improve its identification with ethmomaxillary sinus (EMS). METHODS: The paranasal sinus CT scans of 441 outpatients or inpatients in our hospital from January 2018 to October 2018 were analyzed. The incidence of RMC, EMS, Haller cell, imaging anatomical characteristics, and morphological manifestations were observed via sinus CTs. The relationship of RMC and ipsilateral maxillary sinusitis was analyzed. RESULTS: The incidence of RMC is 83.90% (740/882). The incidence of males and females was 83.81% (414/494) and 84.02% (326/388), respectively. The incidence of bilateral (72.79%, 321/441) was much higher than that of unilateral (22.22%, 98/441). The lateral extension of the RMC ranged from 1.18 to 13.31 mm, with an average of 6.10 ± 2.03 mm. The incidence of ipsilateral maxillary sinus opacification on the RMC sides and non-RMC sides has no significance difference (χ2 = .054, P = .459). The incidence of Haller cell and EMS decreased significantly in the presence of RMC (P < .01). CONCLUSION: The RMC is an anatomical variation originating from posterior ethmoid cells, which is commonly encountered in the clinic. The pneumatization of RMC is highly variable, and a bilateral is common. During endoscopic sinus surgery, it is necessary to carefully identify such an air cell to ensure the complete opening of the paranasal sinus during surgery.

Active airflow of the paranasal sinuses in extinct crocodyliforms: Evidence from a natural cast of the thalattosuchian Dakosaurus andiniensis.

The evolution of Thalattosuchia documents the unique shift among Crocodylomorpha from aquatic continental/coastal habitats to a fully pelagic lifestyle. This transition was coupled with deep modification of their skeletons, such as hydrofoil forelimbs, hypocercal tail, and loss of osteoderms. The natural snout casts of the rhacheosaurin Cricosaurus araucanensis showed that it also included changes in the internal anatomy of the snout like the enlargement of nasal glands (probably for salt excretion) and the rearrangement of the paranasal sinus system, including the internalization of the antorbital sinus. Here we described the snout natural cast of the geosaurin Dakosaurus andiniensis from the Late Jurassic of Patagonia. The information provided by it indicates that, despite having different external morphologies and ecology, D. andiniensis and C. araucanensis share the same facial anatomy. The new cast preserves a suborbital diverticulum of the antorbital sinus protruding into the orbit through the postnasal fenestra. Its location indicates that it was interleaved with jaw adductor muscles suggesting an active airflow in the paranasal sinus. We provide a putative functional interpretation of this peculiar arrangement where bellow pumps actions of musculature may help drain salt glands. The rearrangement of the paranasal sinuses predates the transition to a completely pelagic-lifestyle. We proposed a stepwise evolutionary scenario of Thalattosuchia, implying changes in the preorbital region (and orbit orientation) where the internalized antorbital sinus via its subsidiary diverticulum was co-opted for helping nasal glands drainage. Further scrutiny of facial anatomy of a larger sample of thalattosuchians will help to test this hypothesis.

Applied anatomy of the skull in the Arabian horse: A computed tomographic, cross-sectional, volumetric and morphometric study.

This study was conducted to present a comprehensive and integrative computed tomography (CT) - anatomical cross sections atlas of skull, volumetric properties of the paranasal sinuses, and morphometric values for surface cranial nerves in the adult Arabian horse. Ten heads of Arabian horse breed were used. The different structures in the nasal, oral and cranial cavities were determined and labelled in the anatomical sections and their corresponding CT scan images. Three paranasal sinuses namely maxillary, conchofrontal and sphenopalatine sinuses were identified in the CT scan images. The caudal maxillary sinus was the largest paranasal sinus with 131.93 ± 7.67 cm3 volume and the sphenopalatine sinus 13.3 ± 1.2 cm3 volume was the smallest one. The infraorbital foramen was located 4.16 ± 0.18 cm and 4.70 ± 0.35 cm far away from the most rostral point of the facial crest and alveolar root, respectively. The mean distance between the mental foramen and most lateral incisive tooth was 3.12 ± 0.29 cm. These results including present CT scan-cross-sectional atlas, paranasal sinuses volume and morphometric properties would be applicable in practice for more precise diagnosis of head lesions and blocking the surface terminal branches of the cranial nerves during surgical operations in this valuable horse's breed.

Macroscopic anatomy, radiography and computed tomography of normal paranasal sinuses of the adult one-humped dromedary (Camelus dromedarius).

In order to improve the current knowledge of the topography and the anatomy of the paranasal sinuses of the one-humped dromedary (Camelus dromedarius), we applied both conventional and advanced imaging techniques, namely, radiography and computed tomography (CT). Twelve heads of healthy dromedaries were used; eight heads were dissected to obtain skulls for the fenestration of the sinuses, two heads underwent anatomical sections, and two heads were imaged respectively by radiography and CT. Sinus fenestration allowed observation of sinuses and their communications. In each dissected dromedary's head, the frontal sinus is a large compartment delimited by thick partitions. The sphenoid sinus is divided into small compartments by bony plates. The lacrimal sinus occupies a small cavity in the rostro-medial lacrimal bone of the orbit. In all dissected heads, there was neither palatal sinus nor ventral conchal sinus. Five images obtained by CT were selected with an excellent correspondence with the anatomical sections. These images allowed a good differentiation between bones and sinus cavities. The visualisation of the sinus cavities and their anatomical limits has better quality using the CT compared to the radiography. Radiographic and CT images are therefore very useful for the interpretation of clinical imaging studies of the dromedary's paranasal sinuses.

The skull of the Miocene Spheniscus urbinai (Aves, Sphenisciformes): osteology, brain morphology, and the cranial pneumatic systems.

Spheniscus urbinai represents one of four extinct Spheniscus species from the Cenozoic of southern South America, known from several poorly described diversely complete skulls and postcranial elements. Here, we present a review of the cranial osteology of all known specimens (collected in Argentina, Chile, and Peru), including a paleoneurological analysis using CT scans, and an exploration of its cranial pneumaticity compared to other extinct and living seabirds. Our results show that among Spheniscus species, S. urbinai exhibits slightly greater cranial pneumaticity than the living species. Additionally, we confirm previous findings which indicate that the marked reduction of cranial pneumaticity-which is characteristic of living penguins-occurred early during the Eocene (as observed in the Antarctic penguin MLP 12-I-20-1, but not in the coeval Anthropornis).

Volumetric measurements of paranasal sinuses and examination of sinonasal communication in healthy Shetland ponies: anatomical and morphometric characteristics using computed tomography.

BACKGROUND: Despite clinical importance and frequent occurrence of sinus disease, little is known about the size of paranasal sinuses and their communication in ponies and small horses. To examine the shape and volume of the paranasal sinuses and evaluate the sinonasal communication, three-dimensional (3D) reconstructions of computed tomography (CT) datasets of 12 healthy adult Shetland ponies were performed and analysed. Linear measurements of head length and width were taken. Using semi-automatic segmentation, 3D-models of all sinus compartments were created. Volumetric measurement of the seven sinus compartments were conducted and statistical analysis was performed. Sinus volumes were compared between the left and right sinuses and the relation to age and head size was evaluated. RESULTS: Structure and shape of the paranasal sinus system in Shetland ponies was similar to that of large horses. All seven sinus compartments on each side of the head were identified (rostral maxillary sinus, ventral conchal sinus, caudal maxillary sinus, dorsal conchal sinus, middle conchal sinus, frontal sinus, sphenopalatine sinus). The existence of a bilateral cranial and a caudal system formed by a maxillary septum was visible in all 12 individuals. The volumetric sizes of the left and right sinuses did not differ significantly (p > 0.05). A positive correlation between the size of the paranasal sinuses and the head length was shown. A relation between sinus volumes and age could not be proved in adult ponies aged > six years. Communication between single sinus compartments was identified. Furthermore, communication with the nasal cavity over the nasomaxillary aperture (Apertura nasomaxillaris) and a common sinonasal channel (Canalis sinunasalis communis) as well as its splitting up into a rostral and a caudolateral channel could be seen. Examination of the sinonasal communication was challenging and only a descriptive evaluation was possible. CONCLUSIONS: Our findings concerning the size, shape and volumetric dimensions of Shetland pony CT images could help improve CT interpretation of abnormal clinical cases as well as aiding clinicians to develop and select appropriate instruments for medical inspection and treatments.

The dimensions of the sphenoid sinuses: evaluation before the functional endoscopic sinus surgery.

BACKGROUND: The following study aimed to evaluate the dimensions (anteroposterior, transverse and vertical) of the sphenoid sinuses in the adult population. MATERIALS AND METHODS: The study was conducted as a retrospective analysis of the computed tomography (CT) scans of the paranasal sinuses of 296 patients (147 females and 149 males), who did not present any pathology in the sphenoid sinuses. The CT scans of the paranasal sinuses were done with the spiral CT scanner, without using any contrast medium. After obtaining transverse planes, frontal and sagittal planes were created using secondary reconstruction tool. RESULTS: The anteroposterior dimension was found to be 2.65 cm on average, in the range of 0.5-4.3 cm. The transverse dimension was on average 1.98 cm, ranging from 0.5 cm to 4.9 cm. The average vertical dimension was found to be 2.1 cm, in the range of 0.7-3.7 cm. CONCLUSIONS: Due to the high incidence of the anatomical variants of the paranasal sinuses, a CT scan is recommended in all patients before a planned surgery in order to avoid the potential iatrogenic complications. Dimensions of the sphenoid sinuses might point towards more at risk variants, but there is still a substantial amount of research that needs to be done in that aspect.