Tomographic characteristics of the frontal sinus in a public hospital in Peru

The frontal sinus is the paranasal cavity with the greatest anatomical variability. Since the level of difficulty in dissecting the frontal recess during surgery is directly related to these anatomical variations, identifying them in the preoperative stage is crucial. This study aims to determine the most prevalent tomographic characteristics of the frontal sinus in paranasal sinus CT scans performed at a tertiary-level hospital in Lima, Peru, during the period 2023-2024.

This is an observational, descriptive, cross-sectional study. Paranasal sinus CT scans obtained between July 2023 and June 2024 were analyzed. Sinus morphology, anteroposterior diameter of the frontal ostium, frontal angle, and frontal ostium grade were evaluated. Identification of ethmoidal cells and measurement of the distance from the columella to the frontal beak and to the anterior skull base were also included. Data was collected using Excel spreadsheets, and frequency tabulations were performed using IBM SPSS Statistics software.

A total of 328 CT scans were included. In our sample, the most frequent age group was 30-59 years (54.6%), and the female sex predominated (55.2%). The most frequent morphology of the frontal sinus was medium size (66.5% on the right side and 59.5% on the left side). Hyperplasia predominated in males. More than 60% of the analyzed CT scans presented an anteroposterior distance of the frontal ostium between 5-10 mm (64.63% on the right side and 60.98% on the left). Adults over 30 years of age showed a diameter >10 mm more frequently than those aged 18-29 years. The frontal angle between 45° and <60° was the most frequent (65.55% on the right side and 62.80% on the left), and the most common grade was positive (62.80% on the right side and 65.55% on the left). The mean D-CFB was approximately 5.6 mm on the right side and 5.7 mm on the left side. Males presented greater measurements (approximately 0.5 mm more) than females. The mean D-CASB was 6.39 mm (right) and 6.53 mm (left). Males presented a significantly greater distance (∼0.5-0.6 mm more) than females (P < .001). The most prevalent cells were the agger nasi cell (90.55% on the right side and 92.38% on the left side) and the suprabullar cell (67.68% on the right side and 72.26% on the left side).

This study provides a detailed tomographic characterization of the frontal sinus in a Peruvian population, serving as a theoretical basis to optimize surgical planning and anticipate potential challenges in the endoscopic approach to this anatomical region. The IFAC classification, frontal ostium diameter, and frontal angle are key factors to consider in surgical decision-making.