Analysis of frontal sinus ostium variants based on computed tomography data

Abstract

Introduction. The structure of the nasal cavity and the sinonasal region is crucial in selecting treatment methods for their pathologies. Endoscopic surgery of the frontal sinus requires an assessment of the position and diameter of the frontal ostium, which can be determined and classified by analyzing a series of sinonasal computed tomography scans. The aim of our study was to investigate possible variations in the position and dimensions of the frontal sinus ostium and determine their frequency in individuals of mature age using computered tomography data.Material and methods. The study was conducted by analyzing 40 series of anonymized archived computer scans of 20 men and 20 women of mature age. The material for the study was obtained at the "Lithotripsy Center" (Lviv) on the Siemens SOMATOM GO.UP 32 (64) device (Germany). The evaluation and determination of the frontal ostium diameter were performed using the method described by Gheriani H. et al.[5].Results. Three variants of frontal sinus ostia were identified: with a positive, neutral, and negative evaluation. In 70% of examined women and 60% of examined men, the frontal sinus ostia received a positive evaluation on both sides, while in 10% of women and 10% of men, it was only on one side. Frontal sinus ostia with a negative evaluation were observed in 20% of women and 10% of men on one side. In 30% of women and 20% of men, the frontal sinus ostia had a neutral evaluation on one side, and in 20% of men, it was on both sides. The diameter of frontal ostia in both groups of men and women showed significant variability. In the studied group of individuals of mature age, the most common category of frontal ostium passability was the second category (50%), and the rarest was the fourth category (10%). The frequency of visualization of frontal ostia of the first and third categories was 45% and 30%, respectively. The symmetry of categories passability of frontal ostia in men was 80%, which was twice as high as in women. In men, the first category of frontal ostium patency was most frequently observed (50% of examined men), while in women, it was the second category (80% of examined women). The fourth category of frontal ostium passability was the least common in both men and women, each accounting for 10% of individuals of both genders.Conclusion. Computed tomography allows to determine the position and size of the frontal sinus ostium, which is crucial for assessing the complexity of surgical intervention.