Pneumocephalus with Inverted Papilloma in the Frontoethmoidal Sinus: Case Report and Literature Review.

Here, we describe the unique case of a pneumocephalus originating from an inverted papilloma (IP) in the frontoethmoidal sinus. A 71-year-old man with diabetes presented with headaches and altered consciousness. Imaging revealed the pneumocephalus together with bone destruction in the left frontal sinus. He underwent simultaneous endoscopic endonasal and transcranial surgery using an ORBEYE exoscope. Pathological diagnosis of the tumor confirmed IP. Post-surgery, the pneumocephalus was significantly resolved and the squamous cell carcinoma antigen level, which had been elevated, decreased. This case underscores the importance of a multidisciplinary approach and innovative surgical methods in treating complex sinonasal pathologies.

CT analysis of frontal recess air cell and fluid dynamics simulation of frontal sinus in people with different frontal sinus development after Draf1-3 surgery.

OBJECTIVE: To explore the effects of Draf1-3 on frontal sinus airflow and frontal sinus irrigation in people with different frontal sinus development METHODS: The development of the frontal sinus and the distribution of the frontal recess cells were evaluated by CT scan in 150 adults (300 sides). The airflow changes into the frontal sinus and frontal recess after Draf were analyzed by Fluent software under a steady state and quiet inspiratory state. Nasal irrigation after Draf in adults with well-developed frontal sinus was simulated using 120 mL saline at a rate of 12 mL/s in a position at 45° to observe the changes in transient flow distribution. RESULTS: The moderately developed type of the frontal sinus was the most common. The airflow patterns in the frontal sinus and frontal recess in the moderate development group were laminar, while several large vortexes were formed between the frontal sinus and frontal recess in the well-development group. The Draf exerted more significant effects on the patterns, pressure, and velocity of the airflow in the frontal sinus and frontal recess in the well development group than in the moderate development group. The volume fraction of saline in the frontal sinus increased significantly from Draf1 to Draf3, and the time required for a complete infiltration of saline in the frontal sinus mucosa was significantly reduced. CONCLUSIONS: Draf1-3 has different effects on the airflow field of the frontal sinus with different developmental types; and Draf1-3 can significantly improve the postoperative flushing of the frontal sinus.

A Brief Clinical Study: Consecutive Occurences of Frontal Sinus Pneumocele.

Sinus pneumocele is a rare condition marked by pathologic expansion of a paranasal sinus with concomitant bone loss. Here, we describe the case of a 24-year-old male who first presented with a 2×3 cm bony projection of his right medial forehead. Exam and history were notably absent for any skin tethering, prior trauma, inflammation, or neurological symptoms. A computed tomography scan confirmed the prominence was secondary to an enlarged right frontal sinus. The pneumocele was successfully corrected through surgery, but the patient notably developed a similar presentation on the left frontal sinus nearly 1 year later. Clinical findings support a hypothesis of air trapping through mucosal thickening. This second pneumocele was managed similarly.

Computed Tomography Evaluation of Frontal Sinus Volume in Migraine Patients.

This study aimed to assess the frontal sinus volume (FSV) on computed tomography (CT) scans in migraine patients. Cranial and paranasal CT images from 75 migraine patients (mean age: 39.14±13.63 y) and 23 control cases (mean age: 38.78±13.32 y) were analyzed retrospectively. Three-dimensionally reconstructed images of frontal sinuses were generated. Total FSV, anterolateral, and transverse diameters of the head were measured. The presence/absence and nature of supraorbital foramen and notches were evaluated. The total FSV was 8.02±5.97 cm 3 in the migraine group and 8.38±4.83 cm 3 in the control group, with no significant differences between them. Mean FSV values showed no statistically significant difference between females (7.79±5.85 cm 3 ) and males (9.12±6.66 cm 3 ) within and between the groups. Single notch was the most observed structure in both groups, with bilateral presence being the most common. Double foramen and notch were observed only in the migraine group, and the coexistence of both structures was higher in the migraine patients than in controls. There was no statistical difference in FSV between migraine and control groups, nor based on sex. Overall, the frontal region anatomy, particularly the exit locations of the supraorbital or supratrochlear foramen/notches, may be influenced by hyperplasia/hypoplasia of FSV. Therefore, assessing FSV using CT may be crucial for surgical planning in migraine patients undergoing open or endoscopic approaches to the frontal region.

The relationship of anterior occlusion and skeletal variables with the frontal sinus index: An analytical cross-sectional study.

OBJECTIVE: To determine the relationship of anterior occlusion and skeletal variables with the frontal sinus index. METHODS: The retrospective, analytical, cross-sectional, study was conducted from July to November 2020 at Dr Ishratul- Ebad Khan Institute of Oral Health Sciences and Dow Dental College, Dow University of Health Sciences, Karachi, and comprised data from 2015 to 2018 related to pre-treatment lateral cephalograms for determining frontal sinus index and other cephalometric variables. The dental casts were observed for incisor classification. Patients with Class I incisors formed the comparison group, while the rest comprised 5 malocclusion groups. The frontal sinus was traced, and the sinus index was calculated. Data was analysed using STATA 15 and R 3.5.1. RESULTS: Of the 240 subjects, there were 40(16.66%) in each of the 6 groups; 155(64.6%) females and 85(35.4%) males. The mean age of the sample was 21.33±3.52 years (range: 16-29 years). The mean sinus index was higher in all malocclusion groups than the comparison group, but it was significantly higher only in Class II division 2 and anterior open bite groups (p<0.05). The only exception to the trend was Class II division 1 with and without contact in which the value was lower (p>0.05). The anterior cranial base length, sella-nasion mandibular plane angle, and upper incisor palatal plane angle significantly affected the frontal sinus index (p<0.05). CONCLUSIONS: The frontal sinus index could be considered an indicator of harmonious anterior occlusion.

Frontal sinus hypoplasia in unoperated older patients with craniosynostosis: a pilot study.

PURPOSE: The purpose of this study is to determine whether patients with unoperated craniosynostosis have different frontal sinus pneumatization than unaffected controls. METHODS: Retrospective review was performed between 2009 and 2020 of previously unoperated patients with craniosynostosis older than 5 years old at first presentation to our institution. Total frontal sinus volume (FSV) was calculated using 3D volume rendering tool in Sectra IDS7 PACS system. Age-matched normative FSV data was collected from 100 normal CT scans for the control group. The two groups were statistically compared using Fisher's exact test and T-test. RESULTS: Study group included nine patients, 5-39 years old, median age 7 years. Frontal sinus pneumatization was absent in 12% of the normal 7-year-old controls, while frontal sinus pneumatization was absent in 89% of the studied craniosynostosis patients (p < .001). Mean FSV of the study group (113 ± 340 mm3) was significantly different from that of age matched control mean FSV (2016 ± 2529 mm3) (p = .027). CONCLUSIONS: Frontal sinus pneumatization is suppressed in unreleased craniosynostosis and may be an intracranial space conservation phenomenon. This absent frontal sinus can have implications in future frontal region trauma and frontal osteotomies.

Change of frontal sinus in age of according to the international frontal sinus anatomy classification.

BACKGROUND: The radiological and surgical anatomy of the frontal sinus should be well-known in all age groups to successfully manage frontal sinus diseases and reduce the risk of complications in sinus surgery. PURPOSE: To define frontal sinus and frontal cells according to the International Frontal Sinus Anatomy Classification (IFAC) criteria in pediatrics and adults. MATERIAL AND METHODS: A total of 320 frontal recess regions of 160 individuals (80 pediatric, 80 adults) who underwent a computed tomography (CT) scan of the paranasal sinus (PNS) were included in the study. Agger nasi cells, supra agger cells, supra agger frontal cells, suprabullar cells, suprabullar frontal cells, supraorbital ethmoid cells, and frontal septal cells were evaluated in the CT analysis. RESULTS: The incidence rates of the investigated cells were determined to be 93.1%, 41.9%, 60.0%, 76.3%, 58.5%, 18.8%, and 0% in the pediatric group, respectively, and 86.3%, 35.0%, 44.4%, 54.4%, 46.9%, 19.4%, and 3.4% in the adult group, respectively. Considering the unilateral and bilateral incidence of the cells, agger nasi cells were highly observed bilaterally in both the pediatric group (89.87%) and the adult group (86.48%). CONCLUSION: Our study results show that IFAC can be used as a guide to increase the chance of surgical treatment in the pediatric and adult groups and that the prevalence of frontal cells can be determined radiologically and contributes to the generation of estimations of the prevalence of frontal cells.

Frontal trans-sinusal approach: how I do it.

BACKGROUND: Anterior skull base lesions could be reached by different approaches (subfrontal, pterional, interhemispheric, etc.). In selected cases, the frontal trans-sinusal approach is an effective alternative to conventional techniques. METHODS: We present our technique to perform a frontal trans-sinusal approach in a patient affected by a large olfactory groove meningioma. DISCUSSION-CONCLUSION: The frontal trans-sinusal approach allows to approach safely lesions of the median anterior cranial fossa. This approach provides lower brain retraction, easier access to olfactory grooves, and earlier tumor devascularization. However, it remains limited to patients with large-sized frontal sinuses and entails some postoperative risks such as mucocele or CSF leak.

Nasal sinuses cholesteatoma: case series and review of the English literature.

BACKGROUND: Nasal sinus cholesteatomas are uncommon slow-growing lesions that are frequently misdiagnosed preoperatively. They can develop due to embryologic remnants or iatrogenic factors (surgical trauma or nasal sinus trauma). In addition, they can cause bone destruction resulting in intracranial or intraorbital complications as well as malignant change if neglected. Complete surgical removal is a must with strict postoperative follow-up. MATERIALS AND METHODS: Three cases of nasal sinus cholesteatoma are reported. The first case was found inside the ethmoidal sinus, the second in the frontal sinus, and the third was found inside a concha bullosa. In all three cases, a wide endoscopic surgical excision was performed. Due to the lateral extension of the lesion, frontal sinus trephine was also used in the case of frontal sinus nasal cholesteatoma. In addition, a review of the English literature for the reported cases of nasal sinus cholesteatomas was conducted. RESULTS: There were no reported recurrence or residual during strict postoperative follow-up for 2 years (by endoscopic examination and diffusion-weighted MRI with delayed postcontrast T1 images). A review of the English literature revealed 42 cases of nasal sinuses cholesteatomas (including the present three cases) (17 in the frontal sinus, 15 in the maxillary sinus, 5 in the ethmoid sinus, 3 in the sphenoid sinus, and 2 in a concha bullosa). CONCLUSIONS: Although nasal sinus cholesteatomas are uncommon, they must be considered in the differential diagnosis of slow-growing nasal sinuses lesions. Preoperative CT scan and diffusion-weighted MRI are essential for proper diagnosis and to exclude other similar lesions, such as nasal sinus mucoceles, cholesterol granuloma, or neoplastic lesions. Wide complete surgical excision is necessary to avoid recurrence and facilitate postoperative follow-up. As with ear cholesteatoma, strict postoperative follow-up is required to detect recurrence or residual early and is performed by endoscopic examination, diffusion-weighted MRI, and delayed post-gadolinium T1 images.

What may surprise a rhinologist in everyday clinical practice: silent sinus syndrome or pneumosinus dilatans/pneumocele? Literature review and own experience.

BACKGROUND: The aim of the study was to present rare sinus syndromes known as silent sinus syndrome (SSS) and frontal sinus syndrome with excessive pneumatization and bone defects in the wall (pneumocele). The available literature describing pneumocele cases was reviewed. METHODOLOGY: PubMed and Science Direct databases were searched by two independent reviewers. The primary outcome was finding descriptions of the sinus pneumocele. In the end, papers on frontal sinus pneumocele that was not the result of trauma, congenital defects or comorbidities were selected. Moreover, the authors presented their own cases of SSS and pneumocele. RESULTS: Twelve case reports of frontal sinus pneumocele were found, one own case was presented. In addition, 8 subjects with SSS, diagnosed and treated in the period from September 2017 to May 2022, were described. CONCLUSIONS: With the increasing number of patients suffering from sinus diseases and the growing number of endoscopic surgeries, the knowledge of rare sinus syndromes will increase the safety of the procedures performed.

Radiological relationship of the ethmoid slit with the frontal sinus and the anterior ethmoidal artery and applications to the frontal sinus drillout.

PURPOSE: To compare two types of CT acquisition parameters: CT scan of the facial bone and CT scan of the sinuses, for studying the ethmoidal slit and its relationship with the frontal sinus and anterior ethmoidal artery. MATERIALS AND METHODS: Retrospective study of 145 scans of the sinuses and 79 of the facial bones performed between 2012 and 2016. On each scan, the visibility of the ethmoidal slits, their length, their distance from the ethmoidal artery, and their relationship with the anterior and posterior wall of the frontal sinus were studied. RESULTS: The ethmoidal slit was better visualized on CT scans of the facial bone (58.2%) than on those of the sinuses (43.1%) (p = 0.02). The distance between the anterior ethmoidal artery and the anterior part of the cribriform plate was 9.3 mm for CT scans of the facial bone and 8.4 mm for CT scans of the sinuses. The theoretical risk of damaging the glabellar soft tissue and that of damaging the meninges during a frontal sinusotomy was evaluated, respectively, at 9.6% and 26.1% for CT scans of the facial bone, and at 6.2% and 21.5% for sinus scans. CONCLUSIONS: CT scans of the facial bone are better than CT scans of the sinuses for identifying ethmoidal slits and their distance from the canal of the anterior ethmoidal artery. The identification of these elements is relevant for the surgeon during frontal sinus surgery and makes it possible to assess the risk of damaging the glabellar soft tissue or meninges. Performing a CT scan of the facial bone seems preferable to that of a CT scan of the sinuses in certain pathological situations, such as cerebrospinal rhinorrhea or revision surgeries of the frontal sinus.

Utility of flexible interventional endoscopy in endoscopic sinus surgery: a case series.

PURPOSE: During endoscopic sinus surgery (ESS), difficult-to-reach pathologies need an extended endoscopic approach or an external approach. We started to use a flexible interventional endoscope (FIE) to evaluate the necessity of those approaches. The study's objective is to describe our experience and define patients who could benefit from this technique. METHODS: We reviewed every patient who benefited from FIE associated with ESS at our tertiary University Hospital between January 2021 and February 2022. RESULTS: During this period, we did 107 ESS, and 14 patients benefited from the FIE, representing 13% of our ESS. The median duration of the flexible endoscopy time was 14 min (4-38 min). We identified three groups of patients who can benefit from the FIE. The first one is for patients with a fungal infection, to control and to clean lateral recesses in a noninvasive manner. The second one is for patients with a pathology of the lateral frontal sinus, to remove the frontoethmoidal cells or mucocele with the biopsy forceps through the working channel. The third group is for patients with inverted papillomas, to precisely identify the insertion and to decide on the most appropriate surgical approach. CONCLUSIONS: In selected cases, using flexible endoscopy during ESS helps decide the optimal surgical approach and sometimes treat the pathology through a limited approach. Prospective studies for each group of patients are needed to confirm the benefit of this new combined procedure.

Anterior ethmoid and frontal sinus drainage pathways: five patterns formed and defined by their bony walls.

PURPOSE: To perform endoscopic sinus surgery safely and effectively, surgeons need to visualize the complex anatomy of the anterior ethmoid and frontal sinus region. Because this anatomy is so variable and individualized, the foundation of understanding lies in identifying, following, and visualizing the drainage pathway patterns and anticipating possible variations. METHODS: We studied 100 sides (50 cases: 22 male, 28 female, aged 12-86, average age 46.5 years, ± 19.5) using computed tomography (CT) and multiplanar reconstruction (MPR) to identify and classify the drainage pathways leading to the frontal sinus and anterior ethmoidal cells. RESULTS: Analysis revealed five patterns of drainage pathways defined by their bony walls: between the uncinate process and the lamina papyracea [UP-LP]; between the uncinate process and the middle turbinate [UP-MT]; between the uncinate process and the accessory uncinate process [UP-UPa]; between the uncinate process and the basal lamella of the ethmoidal bulla [UP-BLEB]; and between the basal lamella of the ethmoidal bulla and the basal lamella of the middle turbinate [BLEB-BLMT]. In most cases, BLEB formed the posterior wall of the drainage pathway of the frontal sinus, indicating BLEB could be one of the most important landmarks for approaching the frontal sinus. CONCLUSIONS: As endoscopic sinus surgery depends on an understanding of this anatomy, this study may help surgeons to identify and follow the drainage pathways more accurately and safely through the anterior ethmoid to the frontal sinus.

Radiopathologic predictors of 1- and 2-year frontal sinusotomy outcomes in a southeast Asian chronic rhinosinusitis population.

BACKGROUND: The frontal sinus and its drainage pathway are difficult spaces to navigate surgically. The complexity of the frontal recess anatomy as well as inflammatory factors may influence outcomes of endoscopic frontal sinusotomy. It is not clear which factors are more important in determining post-operative frontal ostium patency. OBJECTIVE: The objective is to investigate whether the distribution of fronto-ethmoidal cells, frontal recess dimensions and sinonasal inflammation predict frontal ostium patency at 1- and 2-years after endoscopic frontal sinusotomy. METHODS: A retrospective review of 94 chronic rhinosinusitis patients (185 sides) who had undergone endoscopic frontal sinusotomies between 2015 and 2019 was conducted. Computed tomography was used to evaluate the type of fronto-ethmoidal cells present and determine the dimensions of the frontal recess. The International Classification of the Radiological Complexity of frontal recess and frontal sinus was used to grade the complexity of frontal recess anatomy. Mucosal inflammation was graded according to a structured histopathology report. Frontal ostium patency at 1- and 2-years post-operatively was recorded. RESULTS: The frontal ostium patency rates were 80.9% and 73.4% at 1- and 2-years respectively. Eosinophilic predominance (adjusted OR 3.5, 95% CI 1.6-8.0, p = 0.003) and mucosal ulceration on histology (adjusted OR 4.5, 95% CI 1.1-17.9, p = 0.033) predicted ostial stenosis at 1 year. Smoking (adjusted OR 7.6, 95% CI 2.4-24.7, p = 0.001), aspirin exacerbated respiratory disease (AERD) (adjusted OR 7.6, 95% CI 1.9-30.1, p = 0.004) and histological findings of severe inflammation (adjusted OR 8.9, 95% CI 1.9-41.2, p = 0.005) were independent predictors of ostial stenosis at 2 years. Frontal cell patterns, frontal recess dimensions and frontal recess complexity did not predict frontal ostium stenosis at both 1- and 2-years post-operatively. CONCLUSION: Post-operative control of sinonasal inflammation is important in maintaining frontal ostium patency, regardless of frontal cell patterns or frontal recess dimensions.

Computed tomographic characteristics of frontal sinus ossifying fibroma in a dog.

A 10-year-old female spayed Kelpie cross was presented to The Austin Vet Specialists for further investigation of a mineralized, lobulated frontal sinus mass that had previously been detected radiographically. Computed tomography (CT) revealed a large, expansile, well-defined, heterogeneously mineral attenuating mass invading both frontal sinuses. The mass was surgically debulked via a frontal sinusotomy approach. Histopathology was consistent with ossifying fibroma. This  is the first published report to describe frontal sinus ossifying fibroma in a dog, and the second to describe CT features of ossifying fibroma involving the cranium in a dog.

Reliability of gender determination from paranasal sinuses and its application in forensic identification-a systematic review and meta-analysis.

This systematic review aims to determine whether linear or morphometric analysis of paranasal sinuses can be used for accurate determination of gender and to appraise which sinus can be evaluated for accurate gender determination.A comprehensive search of the specialized databases (PubMed/MEDLINE, Science Direct, Clinical Key, ProQuest, Google Scholar, Epistomonikos, LILACS, OpenGrey) and other institutional repositories was performed for including the studies which assessed paranasal sinuses for gender determination. Quality assessment was carried out with the AQUA tool. The meta-analysis was performed with the eligible study data at 95% CI and p ≤ 0.05 in the random-effects model.Forty-six studies evaluating frontal sinus (13), maxillary sinus (26), frontal and maxillary sinus (5), or three paranasal sinuses (2) were included. All the included studies assessed height, length, width, and volume, respectively, and other additional parameters (area, perimeter) if wherever applicable. Frontal sinus had significantly higher values for males compared to females except for left height (LH) and left volume (LV). Maxillary sinus measurements were significantly higher in males contrasted to females except for LH. Sub-group analyses revealed that analyses involving the population had statistically significant results for all the measured parameters for both the sinuses (p < 0.05 and p = 0.00, respectively).Measurements obtained from assessing sinuses reveal that there are variations in size, among populations in different geographic regions. Hence, more studies with improved sample sizes and standardized measurement protocols should be carried out on different populations to see the diversity and their reliability.

[Frontal sinus anatomical scanographic study of transgender patients for feminization frontoorbitoplasty surgery]. / Étude anatomique scanographique du sinus frontal des patients transgenres en vue d'une chirurgie de frontoorbitoplastie de féminisation.

INTRODUCTION: Little is known about the anatomical elements that allow safe and predictable performance of fronto orbital surgery for facial feminization. The primary objective of this study was to analyze the characteristics (dimensions, pneumatization rate, and anterior wall thickness) of the frontal sinus in MtF transgender patients. The secondary objective was to establish reproducible criteria for CT measurements that could guide preoperative planning of frontal impaction in feminization frontoplasty (FF). MATERIALS: Fifty preoperative facial mass scans of FF surgery patients were included. The mean age of the operated patients was 34 years. The F line represented the ideal forehead tilt in the absence of a frontal hump. RESULTS: The height, width, depth, and thickness of the anterior sinus wall were 26.6mm (±5.7), 49.5mm (±11.3), 10.9mm (±3.3), and 3mm (±0.7), respectively. The mean sinus width to skull width ratio was 0.73 (±0.12). Six percent of patients had bilateral frontal sinus agenesis. An osteotomy of the anterior wall of the frontal sinus was performed in the 64% of patients with frontal sinus projection anterior to the F-line. The emergence of the supraorbital nerves from the frontal bone was through a bony notch in 73.8% of cases. CONCLUSIONS: Knowledge of the anatomy of the frontal sinus and preoperative study of the scans of the facial mass is essential for planning the FF. These characteristics guide the surgical technique of bone remodeling as well as the procedure for releasing the supraorbital nerves.

Ontogenetic patterns in human frontal sinus shape: A longitudinal study using elliptical Fourier analysis.

Frontal sinus morphology is highly variable across individuals, but little is known regarding how or at what age that variation is reached. Existing ontogenetic studies are conflicting and often cross-sectional in nature, limiting understanding of individualistic growth. Studies investigating sinus growth with longitudinal series often focus on lateral cephalograms and consequently do not capture the sinus morphological features that are most relevant to clinical and medicolegal settings (e.g., arcade/scalloping, width-to-height dimensions, asymmetry). Longitudinal analysis of sinus morphology from frontal radiographs is important to understand when sinus morphology stabilizes. The purpose of this study was to investigate at what age the frontal sinus attains its final shape, and whether sex-based differences in ontogeny are evident, using a longitudinal sample of posterior-anterior (PA) frontal radiographs from the AAOF Legacy Collection. Frontal sinus outlines were manually traced in 935 radiographs from 111 individuals (55F/56M) spanning 8-29 years of age. Outlines were subjected to elliptical Fourier analysis (EFA) and underwent principal components analysis (PCA). PC1 (51.02% of variation) appears to represent the relative height and breadth of the sinus, PC2 (11.73%) and PC3 (10.03%) captures the degree of relative complexity in the outlines. Individual PC scores were plotted against age-in-months with individual Loess growth curves. Overall, younger individuals typically display relatively shorter, flatter sinuses, increasing in vertical complexity with age. Mixed-effect models on PC1 indicate significant effects for the repeated measure of years (p < 0.001). Within individuals, Euclidean distances of PCs between each sinus outline and their oldest-age outline (i.e., final morphology) were calculated and plotted against age-in-months with Loess growth curves. The results indicate that final frontal sinus morphology is mostly attained by 20 yoa regardless of sex. There is sexual dimorphism in ontogenetic trajectories: females attain frontal sinus shape earlier than males. Specifically, Loess growth curves of the Euclidean distances to final sinus shape indicate that female shape shows decreased development at 14-16 yoa, with males approaching stabilization at 18-20 yoa. These trends were supported by paired t-tests on PC1 between each year and the oldest age, whereby significant differences end for females starting at 15 and 18 yoa for males. The timing of shape-stabilization in the current study closely aligns with previous studies on linear and size dimensions, indicating a close relationship between the ontogeny of frontal sinus shape and size. This research has several implications in diverse fields. Documenting ontogenetic patterns in modern humans could lead to more accurate interpretations of frontal sinus variation in hominin lineages. Understanding the age at which frontal sinus shape and size stabilizes in pediatric populations has important clinical implications, with future studies needed to investigate if/how sinus development directly relates to sinonasal disease susceptibility (e.g., sinusitis), surgical complications, and/or expected trauma patterns. For forensic practitioners utilizing frontal sinus comparisons for decedent identifications, it is important to know at what age these features stabilize to understand how much change may be expected between antemortem and postmortem radiographs.

The prevalence of frontal cell variants according to the International Frontal Sinus Anatomy Classification and their associations with frontal sinusitis.

BACKGROUND: The International Frontal Sinus Anatomy Classification (IFAC) is introduced to simplify the classification of different frontal cell variants based on their topographical structures. The objectives of our study were to determine the prevalence of the frontal cell variants according to IFAC and their association with the development of frontal sinusitis. METHODOLOGY: A retrospective chart review on computed tomography paranasal sinus (CTPNS) was conducted. A total of 200 patients who had clinical and endoscopic findings of chronic rhinosinusitis (CRS) and undergone CTPNS were reviewed. The CTPNS was evaluated for the presence of frontal cell variants according to IFAC and mucosal changes consistent with frontal sinus involvement. RESULT: A total of 400 sides of the CTPNS were analyzed. The agger nasi cells (ANCs) were the most common (95.5%) followed by supra bulla cells (SBCs) (60.8%), supra bulla frontal cells (SBFCs) (53.0%), supra agger cells (SACs) (50.0%), supra agger frontal cells (SAFCs) (36.0%), frontal septal cells (FSCs) (8.3%), and supraorbital ethmoidal cells SOECs (5.5%). There was significant association between SOEC (p = 0.001) and FSC (p = 0.044) with the development of frontal sinusitis. CONCLUSIONS: Apart from ANCs, the posterior-based cells (SBCs and SBFCs) have higher prevalence than the anterior-based cells (SACs and SAFCs). Despite being the least, both SOECs and FSCs are significantly associated with frontal sinusitis.

Defining the limits and indications of the Draf III endoscopic approach to the lateral frontal sinus and maximizing visualization and maneuverability: a cadaveric and radiological study.

PURPOSE: The DRAF III procedure has been used for access to the lateralmost part of the frontal sinus. We sought to identify anatomical and radiological measurements as well as modifications that predict the lateral limits of visualization and surgical access after this procedure. METHODS: Seven cadaver heads were imaged with computed tomography scan. The distance from midline to the medial orbital wall (MOWD), midline to the lateral end of the frontal sinus (MLD), the sum of MLDs (SMLD), interorbital distance (IOD) and the shortest anteroposterior distance of the frontal recess (APD) were utilized. The ratios MLD/MOWD, and SMLD/IOD were calculated. The same distances were measured on 41 CT scans. Orbital transposition (OT) and partial resection of the piriform aperture (PAR) were performed; the visualization and reach were assessed. The angle of insertion was measured before and after the modifications. RESULTS: Only the ratio MLD/MOWD was consistently predictive of access to the lateral, superior and posterior wall of the frontal sinus. Following the modifications, a visualization of 100% laterally was achieved with the 30- and 45 degree endoscopes and every lateral recess could be reached with the 70 degree suction. A mean increase of the angle of insertion of 25.3 and 59.6% was recorded after OT and PAR, respectively. CONCLUSIONS: IOD rather than APD defines the limits of the Draf III approach to the lateral frontal sinus and MLD/MOWD ratio can serve as a useful preoperative tool. Along to the already described OT, PAR increases visualization and reach of the lateral frontal sinus.