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.

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.

Biological relationships and frontal sinus similarity in skeletal remains with known genealogical data.

Frontal sinus analysis has potential utility for detecting biologically related individuals. However, the methodological approach to its evaluation, as well as its informative value, have been questioned. The aim of this work is to introduce a new approach to evaluating the frontal sinus using the 'external supraorbital line' (ESOL) and to determine whether there are sex differences within families in frontal sinus measurements and whether frontal sinus similarity reflects known genetic relationships in both measurements and morphology. We examined the skeletal remains of 41 adult individuals (25 males, 16 females), all members of one family over four generations (19th to 20th centuries), including individuals with very close consanguinity. CT images of skulls were acquired, and both the dimensions and morphology of the frontal sinuses were analyzed using their portions above the ESOL. No significant sex differences were found within families based on frontal sinus dimensions. Significant relationships were found between biological distance and the maximum height and morphology of the frontal sinuses. The greatest degree of similarity was found among closely related individuals. Additionally, in several cases, there was a greater degree of similarity between first cousins or grandparents and their grandchildren than among siblings or parents and their children. Total surface, volume and width are not significant indicators of relatedness. Known genetic relationships are also supported by individual morphological features. Variability within families with very close consanguineous relationships was lower than within families with common degrees of consanguinity, although differences are significant only for some variables.

Incidence of anatomical variations according to the International Frontal Sinus Anatomy Classification (IFAC) and their coincidence with radiological sings of opacification.

BACKGROUND: The endonasal access to the frontal recess and sinus may be complicated by a variety of anatomical variations. Previous classifications of these variants were characterized by proper names or position information without anatomical reference. The IFAC is intended to simplify the classification of anatomical variations of the frontoethmoidal complex. The aim of this study was to analyse a representative number of sinus CT scans to assess the incidence of anatomical variations according to the IFAC and to compare the results with previous classifications. In addition, the coincidence of complex anatomical variations and radiological sings of opacification was investigated. METHODOLOGY/PRINCIPAL: Two hundred and forty-nine sinus CT scans were analysed in multiplanar reconstructions. Exclusion criteria were previous operations on the paranasal sinuses, malignant diseases, and an insufficient image quality. All anatomical variants were analysed according to the IFAC criteria. In addition, the coincidence of radiological sings of opacification and the presence of anatomical variations of the frontal recess and sinus were investigated. RESULTS: The analysis revealed Agger nasi cells in 95% of the CT scans. Supra agger cells (SACs) were detected in 49% and Supra agger frontal cells (SAFCs) in 25% of the data sets. Suprabulla cells (SBCs) were detected in 89% and Supra bulla frontal cells (SBFCs) in 27% of the scans. Supraorbital ethmoid cells (SECs) were detectable in 9% and interfrontal septal cells in 28% of the scans. Despite a partially strong narrowing of the frontal recess, no increased occurrence of radiological sings of opacification could be detected (p > 0.05). CONCLUSIONS: Anatomical variations in the frontoethmoidal area are very common. According to the IFAC criteria, in 43% of the patients, cells could be detected with pneumatization to or into the frontal sinus. The IFAC is structured more clearly compared to previous classifications due to the anatomical aspect. It represents the most consistent classification regarding surgical planning. Further studies will demonstrate the scientific and clinical value of this classification.

Frontal Sinus Anatomy Variations in Race and Sex Using the International Frontal Sinus Anatomy Classification.

Objective: To identify frontal sinus anatomical variations grouped by patient sex, race, and presence of chronic rhinosinusitis with frontal sinus involvement (CRFS) using the International Frontal Sinus Anatomy Classification (IFAC) system. Methods: A retrospective review from 2015 to 2020 was performed of consecutive adult patients with computed tomography sinus imaging. Prevalence of frontal sinus cells using the IFAC system was recorded. Comparisons were made between patient race, sex, and CRFS groups. Results: A total of 184 patients (368 sides) were included, 90 (48.9%) of which had CRFS. The racial distribution was 50 white (27.2%), 50 black (27.2%), 45 Hispanic/Latino (24.5%), and 39 Asian (21.2%) patients. The supra agger cell was most prevalent in the white population (P = 0.009), and supraorbital ethmoid cells were more prevalent in the Asian population (P = 0.017). Patients with frontal sinus disease were more likely to have a supraorbital ethmoid cell (P = 0.024). Overall, CRFS was more prevalent in the Asian population (P = 0.013). Conclusion: Significant differences in frontal sinus anatomy and disease exist between patient race and sex. Supraorbital ethmoid cells are associated with the development of CRFS. These patterns in frontal sinus anatomy should be noted prior to frontal sinus surgery to improve surgical awareness and outcomes.

Use of 3D-Printed and 2D-Illustrated International Frontal Sinus Anatomy Classification Anatomic Models for Resident Education.

OBJECTIVE: To examine the impact of 2-dimensional (2D) illustrations and 3-dimensonal (3D)-printed anatomic models of the frontal sinuses according to the International Frontal Sinus Anatomy Classification in the education of otolaryngology and radiology residents. STUDY DESIGN: A crossover study design with half of the study participants randomized to the 2D illustration intervention first and the other half randomized to the 3D-printed model first. SETTING: Regularly scheduled resident didactic lectures at a tertiary care center. SUBJECTS AND METHODS: Forty-one otolaryngology and radiology residents were assessed with pre- and postintervention questionnaires that included subjective and objective methods of assessment. RESULTS: Overall, there was a statistically significant improvement in total number of answers correct and in confidence score between the pre- and postintervention assessments (P < .0001). The primary outcome of order of intervention (ie, 2D → 3D vs 3D → 2D) did not result in statistically significant differences in postevaluation scores. In regard to the secondary outcome of learner preference for educational modality, radiology residents favored the 2D illustrations to understand anatomic relationships, while otolaryngology residents preferred the 3D model to be more helpful in surgical planning (P = .0075). CONCLUSION: There is no difference between 2D-illustrated and 3D-printed International Frontal Sinus Anatomy Classification anatomic models in overall educational outcome, despite the preference of learners. Together, these models can be used as helpful tools in frontal sinus education for otolaryngology and radiology trainees.

The Bifurcated Frontal Sinus.

OBJECTIVES: Frontal sinus anatomy is complex, and multiple variations of ethmoid pneumatization have been described that affect the frontal outflow tract. In addition, the lumen proper of the frontal sinus may exist as 2 separate parallel cavities that share an ipsilateral outflow tract. This variant has not been previously described and may have implications for surgical management. STUDY DESIGN: Case series. SETTING: Tertiary rhinology practice. SUBJECTS AND METHODS: Cases with radiographic and intraoperative findings of separate parallel tracts within a unilateral frontal sinus were identified from a consecutive series of 186 patients who underwent endoscopic sinus surgery between May 2015 and July 2016. Data were recorded including sinusitis phenotype, coexisting frontal cells, and extent of surgery. RESULTS: Ten patients (5.4%) were identified with computed tomography scans demonstrating bifurcation of the frontal sinus into distinct medial and lateral lumens. All cases were treated with Draf 2a or 2b frontal sinusotomy with partial removal of the common wall to create a unified ipsilateral frontal ostium. Eleven sides had a coexisting ipsilateral agger nasi cell, 7 had a supra-agger cell, 8 had a suprabullar cell, and 1 had a frontal septal cell. There were no significant complications. CONCLUSION: The bifurcated frontal sinus is an anatomic variant that the surgeon should recognize to optimize surgical outcomes. Failure to do so may result in incomplete clearance of the sinus and residual disease. The bifurcated sinus may occur with other types of frontal sinus cells and may be safely treated with endoscopic techniques.

Computed tomography analysis of frontal cell prevalence according to the International Frontal Sinus Anatomy Classification.

BACKGROUND: The International Frontal Sinus Anatomy Classification (IFAC) is an international consensus document published in 2016 to standardize the nomenclature of cells in the region of the frontal recess and frontal sinus. The IFAC was designed to be surgically relevant and anatomically precise. The current study was undertaken to assess the prevalence of the frontal cell variants as defined by the IFAC, as well as to determine the interrater reliability of the IFAC. METHODS: Three independent reviewers examined triplanar nondiseased maxillofacial computed tomography (CT) scans to assess the anatomy of the frontal recess according to the IFAC system. The prevalence of each cell type was assessed and interrater reliability was measured using an intraclass correlation coefficient (ICC). RESULTS: One hundred CT scans (200 sides) were examined. Of the 200 sides, 96.5% contained an agger nasi cell (ICC, 0.82; 95% confidence interval [CI], 0.77-0.86), 30.0% contained a supra agger cell (ICC, 0.89; 95% CI, 0.86-0.92), 20.0% contained a supra agger frontal cell (ICC 0.80; 95% CI 0.74-0.84), 72.0% contained a supra bulla cell (ICC, 0.81; 95% CI, 0.76-0.85), 5.5% contained a supra bulla frontal cell (ICC, 0.71; 95% CI, 0.63-0.77), 28.5% contained a supraorbital ethmoid cell (ICC, 0.78; 95% CI, 0.72-0.83), and 30.0% contained a frontal septal cell (ICC, 0.80; 95% CI, 0.74-0.84). The ICC was good to excellent for identification of all frontal cell types. CONCLUSIONS: This study describes the normative distribution of frontal recess cells in a nondiseased population according to IFAC and demonstrates favorable interrater reliability of the classification system.

Virtual Mapping of the Frontal Recess: Guiding Safe and Efficient Frontal Sinus Surgery.

Objective To define relationships between the frontal sinus opening, ostia of other frontal recess cells, and endoscopic landmarks and to develop a clinically useful framework to guide frontal sinus surgery. Study Design Retrospective review. Setting Tertiary care academic referral center. Methods Adult patients with computed tomography (CT) without sinonasal pathology were included. Virtual endoscopy (using OsiriX) and corresponding CT reconstructions were used to identify all visible ostia in the frontal recess and characterize their positions in spaces between the uncinate/agger nasi (U), bulla ethmoidalis (EB), and middle turbinate (MT). Results Two hundred sides in 100 patients (median age 51 years, 62% female) were analyzed. The "center" of each map was defined as the intersection of spaces between U, EB, and MT. The frontal sinus opening was in the "center" in 53% of frontal recesses, lateral to this position in 29%, and anterior in 11%. When the frontal sinus opening was at the "center," anterior ostia drained frontal Kuhn T cells in 51% and intersinus septal cells in 23%. The skull base attachment of the apical strut of the uncinate process demarcated medial and lateral within the space between U and EB, with the opening to the frontal sinus medial in 68% and lateral in 31%. Left-right asymmetry in frontal sinus openings was noted in 46% of patients. Conclusion Combining preoperative imaging and knowledge of these anatomic relationships may facilitate more efficient frontal outflow tract identification and instrumentation. This represents the first and largest description of ostial configurations relative to endoscopic structural landmarks. LEVEL OF EVIDENCE: 4.