A novel anatomical classification of the frontal sinus: can it be useful in clinical approach to frontal sinusitis?

We aimed to test the clinical relevance of a newly introduced anatomical classification system of the frontal sinus and to investigate the relation between the frontal sinus type according to this system and the development of frontal sinusitis. We retrospectively evaluated the computed tomography images of 808 frontal sinuses of 404 patients and classified the sinuses as small, medium-sized, and large, based on their size and relation to the orbital roof. We related this classification to the presence or absence of the findings of frontal sinusitis including mucosal thickening, retention cyst/polyp, and/or fluid collection. We found that the most common frontal sinus type is medium-sized (65.84%), followed by the small (22.89%) and large (11.26%) types, respectively. There was no significant difference between the right and left sides in terms of frontal sinus type (P<0.05). We recorded sinusitis in 28 (15.1%) small, 180 (33.8%) medium-sized, and 40 (43.9%) large sinuses. And we showed that the prevalence of sinusitis in medium-sized and large sinuses is significantly higher than that in small sinuses for both sides (P values were 0.001 and 0.015, respectively for the right, and 0.005 and 0.001, respectively for the left side). The result obtained in this study may be considered the first step in demonstrating the clinical benefit of this classification. However, there is no doubt that further comprehensive studies with large series are needed to fully determine the clinical relevance of this newly introduced classification system.